Department of Physics, NCUE, Department of Physics, THU, College of Science, NCHU

Welcome ！！

The LDS workshops were initiated in 2017 for promoting researches on nanoscale and low dimensional sciences for local people. Information of previous workshops can be found in this website for your reference:

http://140.120.11.1/LDS/workshops.htm Organized and hosted

Department of Physics and Institute of Nanoscience, NCHU Co-organized

Department of Physics, NCUE, Department of Physics, THU, College of Science, NCHU

Research Center for Sustainable Energy and Nanotechnology, NCHU

Industrial session

Information

Low Dimension Science

Since 2010, Low Dimensional Science Workshop has been held three times a year: Spring, summer and autumn. The workshop was pioneered by researchers situated in central Taiwan to meet and greet researchers with the same interest; Low Dimensional Science – which is how the workshop got its name. Every workshop consists of ~150 attendees who have travelled from different universities all over Taiwan; all with different backgrounds and studies of interests:

Students, professors and researchers from Academia Sinica, National Taiwan University, National Cheng Kung University, Chiayi University are but some of the participants that can be seen at the workshop. This workshop is not restricted to Taiwanese researchers only: Researchers from Japan are also invited as guest speakers to promote and present their research.

During LDS, many researchers will be presenting on the work that they are either knee deep in, or have just gotten their hands on. Through attendance of the LDS, hopefully you can give your ideas and have opportunities to ask and exchange thoughts and in addition, keep pace with the rapid change that is happening within your field of study. With the topic mainly focusing on Nano materials science and condensed matter physics and low-dimensional science, it will allow for in depth exchange in ideas, opinions and thoughts and have researchers leaving with new and budding friendships and ideas.

Introduction to National Chung Hsing University

National Chung Hsing University (NCHU), located in Taichung city, is one of the most historic university in Taiwan. Adjacent to Taichung Precision Science Park, NCHU is the most important academic, research and internet center in central Taiwan. It was founded in 1919 in the Roosevelt Road Campus of National Taiwan University, and was then moved to its present location in 1943.

With overall 18,000 students and nearly one thousands of faculties, it is the third largest comprehensive national university in Taiwan, and is one of the 100 top universities in Asia. NCHU is famous of its excellent Agricultural Science, Veterinary, Life Science, Environmental Conservation, Biotechnology and Fire Prevention Information.

Focusing on the developing into a comprehensive research university, NCHU devoted to researches on cutting-edge science and technologies. Meanwhile it has carried on transformation and integration within the campus. The faculties of the College of Science and College of Engineering collaborated in the research on nano technology and science. With clear academic planning, they has constructed the nano technology talents pool, organized many seminar and forum, and set up Nano Technology and Science Center to foster the educational, research and industrial development of nano technology and science.

NCHU has become one of the top universities in Taiwan since the school was granted under the

"Development Plan for World Class Universities and Research Centers of Excellence program"

funded by the Ministry of Education in 2006. In September, 2010, the Extension Division for In- service and Continuing Education was transformed into the School of Innovation and Industry Liaison. In August, 2011, the College of Social Science & Management was renamed as the College of Management, and the College of Law and Politics was established at the same time.

The main campus contains the College of Liberal Arts, the College of Agriculture and Natural Resources, the College of Science, the College of Engineering, the College of Life Sciences, the College of Veterinary Medicine, the College of Management, the College of Law and Politics, and the School of Innovation and Industry Liaison. It is located in the south of Taichung City and has an area of approximately 53 hectares.

Important Events

Conference session

Day 1

2016/8/28 PM 14:45 Opening ceremony & plenary session Location : Science Building S104 (理學大樓，物理系) Day 2 , 3

2016/8/29-30 AM 9:00 Plenary session, invited talks & oral session Location : Science Building S104

Day3

2016/8/30 PM 15:50 Closing ceremony Location : Science Building S104

Diet Information

Function Location Aug.29(Tue.) Aug.30(Wen.) Aug.31(Thu) Coffee Break 1F square 10:00~10:20 10:00~10:20

Lunches S103 12:00~14:00 12:00-14:00

Coffee Break 1F square 15:30~16:00 15:30~16:00 Banquet 1F square 17:00~19:30 18:00~19:30

8/29(二) 8/30(三) 8/31 (四)

10:00~14:00 報到及海報張貼

11:00~12:00 議程委員會討論

Plenary Session 9:00~10:00 葉文冠教授

Invited Talk 9:00~10:00 程德勝教授 10:00~10:20

Coffee Break

10:00~10:20 Coffee Break Invited Talk

10:20~11:00 吳仁彰教授

10:20~11:10 Oral Session Plenary Session

11:10~12:00 Prof. Kazuhito

Tsukagoshi

14:45～15:00 Open ceremony

12:00 Lunch 12:00 Lunch 14:00~15:30

Oral Session

14:00~15:30 Oral Session Plenary Session

15:00~17:00 Prof. Keiji Ono Prof.邱博文教授

15:30~16:00 Coffee Break

15:30~16:00 Coffee Break 16:00~18:00

Oral Session

16:00 Closing ceremony 17:30 Banquet 18:00 Banquet

19:30~21:30 Forum/Discussion

19：30～交換學生經驗 分享、新進教師經驗分

享

2017 Low Dimensional Science－Program

2017/8/29 DAY 1

10:00~ 14:45 Registration

10:00~ 14:00 Posting Posters

14:45~15:00 Opening ceremony

15:00~17:00 Plenary session

Chair:

Mon-Shu Ho (何孟書)

15:00~16:00 (P1)

Prof. Keiji Ono

Toward high operation temperature of spin qubits in silicon tunnel field-effect transistor Chair:

Mao-Nan Chang (張茂男)

16:00~17:00 (P2)

Prof. Po-Wen Chiu

2D Materials: from Contact to Device Applications

17:00~19:30 Banquet

19:30~21:30 Forum/discussions

2017/8/30 DAY 2

9:00~09:50 Plenary session

Chair:

Mao-Nan Chang (張茂男)

09:00~10:00 (P3)

Prof. Wen-Kuan Yeh

New Paradigm of Nano Device - From More Moore to More than Moore

10:00~10:20 Photo & coffee break

10:20~11:10 Invited talks

Chair:

Chiu-Hsien Wu (吳秋賢)

10:20~11:10 (P4)

Prof. Ren-Jang Wu

Prepared nanomaterials for gaseous ozone and formaldehyde sensors

11:10~12:00 Plenary session

Chair:

Yen-Fu Lin (林彥甫)

11:10~12:00 (P5)

Prof. Kazuhito Tsukagoshi

Self-assembled hetero-structure based on two-dimensional transition metal dichalcogenides

12:00~14:00 Lunch

14:00~15:30 Oral Session A

Chair:

Kuo-Chih Lee (李國誌)

14:00~14:30 (A1)

NCHU Nipapon Suriyawong (甄美英)

Bifacial Pb-Sb-S semiconductor solar cells from transparent copper selenide counter electrode.

14:30~14:50 (A2)

NCHU Ying-Jyun Hong (洪盈君)

Resistive Switching Memory of Ga2O3 14:50~15:10

(A3)

NCHU Jian-Ming Chen(陳建銘)

核金殼磁性奈米粒子增強法拉第磁光效應之特性研究 及在阿茲海默症檢測之應用

15:10~15:30 (A4)

NCHU Yen-Wen Wang (王彥文)

Electro-optical characteristics of amorphous blue phase liquid crystal in different electrode structures

15:30~16:00 coffee break

16:00~18:00 Oral session B

Chair:

Suriyawong Nipapon (甄美英)

16:00~16:30 (B1)

NCHU D. S. Dubyna

Qubit-3D Cavity Arrays for Realization of Circuit Quantum Electrodynamics

16:30~17:00 (B2)

NCHU Zu-Yin Deng (鄧祖因)

Surface plasma enhanced AC magnetization biosensor 17:00~17:20

(B3)

THU Ying-Zuang Chien (錢盈庄)

Fluorescence properties of 4-nm graphene quantum dots

17:20~17:40 (B4)

NCUE You-Ching Tsai (蔡有慶)

Synthesis and Optical Characterization of CuIn1-xGaxSe2 Nanocrystals

17:40~18:00 (B5)

NCHU Ya-Chi Huang (黃雅琦)

Metabolism and Electrical Properties of Silver Nanoparticles on the NIH-3T3 Cells

18:00~19:30 Banquet

19:30~21:00 Poster

2017/8/31 DAY 3

09:00~10:00 Invited talks

Chair:

Chia-Chien Huang (黃家健)

09:00~10:00 (P6)

Prof. Congo Tak-Shing Ching Engineering technologies for healthcare

10:00~10:20 Coffee break

10:20~12:00 Oral session C

Chair:

Zu-Yin Deng (鄧祖因)

10:20~10:50 (C1)

NCHU Yuan-Ming Chang (張原銘)

Broadband omnidirectional light trapping in gold- decorated ZnO nanopillar arrays

10:50~11:10 (C2)

NCHU Te-Chia Sun (孫德嘉)

可電控之介電質覆蓋石墨烯方向耦合波導

11:10~11:30 (C3)

NCHU Hao-Yu Tu (杜浩宇)

Fast electro-optic switching in Liquid Crystal blue phase II

11:30~11:50 (C4)

THU Guan-You Lin (林冠佑)

不同鍛燒溫度的碳膠在染料敏化電池對電極之研究

11:50~14:00 Lunch

14:00~15:30 Oral session D

Chair:

Yun-Lien Hsieh (謝昀璉)

14:00~14:20 (D1)

NCUE Sheng-Zhe Ciou (邱聖哲)

Fabrication and characterization of magnetic field sensors using giant magnetoresistance devices

14:20~14:40 (D2)

NCHU Yu-Chun Wu (吳宇鈞)

極短之混和表面電漿子極化光分離器設計

14:40~15:00 (D3)

NCHU Wei-Wun Jheng (鄭偉文) Strain sensor base on gold nanoparticles

15:00~15:20 (D4)

NCHU Yu-Te Wu (吳昱德)

The charge transport excited by surface acoustic wave in mechanically exfoliated graphene

15:20~16:00 Coffee break

16:00~ Closing ceremony

Toward high operation temperature of spin qubits in silicon tunnel field-effect transistor (P1)

Keiji Ono^1,2, Takahiro Mori³, and Satoshi Moriyama⁴

1Advanced device laboratory, RIKEN, Wako, Saitama, Japan

2Center for Emergent Matter Science, RIKEN, Wako, Saitama, Japan

3Nanoelectronics Research Institute, AIST, Tsukuba, Japan

4International Center for Materials Nanoarchitectonics, NIMS, Tsukuba, Japan

Qubit attracts great attention as a building block for a quantum computer. A spin qubit in silicon has an advantage in its long coherence, accumulated microfabrication, high-density integration, and connection with classical computers. Spin qubits in silicon have been implemented by gate-defined quantum dots, or by shallow impurities. However, the operation temperature of the state-of-the-art spin qubits has been less than 0.1 K, which limits the expansion of new innovative technology from magnetic sensing to quantum processor. Here we use a deep impunity level in silicon as a novel spin qubit, achieve strong quantum confinement, and demonstrate a qubit operation up to 10 K, more than 100-times higher operation temperature than previous spin qubits.

We adopt tunnel field-field transistor (TFET) structure instead of conventionally employed devices based on metal-oxide-semiconductor field-effect transistors (MOSFETs). Room- temperature single electron tunneling through a single deep impurity is demonstrated in short- channel TFET. The combination of deep and shallow levels forms double quantum dot device, where spin state can be read out by the use of spin blockade.

This results broaden the application of spin qubits thanks to operating them in more accessible temperatures. Our TFET-based device also shed light on the novel electronic functionality of the deep impurities in silicon, which has been studied for a long time and the stored knowledge are available [1].

Fig.1 (a) Schematic of a short-channel TFET and the band diagram showing a single-dot-like transport via a deep impurity level. (b) Conductance vs gate voltage of the single dot like device.

Coulomb conductance peak is observed up to room temperature. (c) Single electron spin resonance observed in a double-dot-like device of the certain gate voltage and source-drain voltage. (d) Single electron spin resonance can be observed up to 10 K.

References

[1] C. A. J. Ammerlaan, et al. Schulz, Max (Ed.), Impurities and Defects in Group IV Elements and III-V Compounds, Landolt-Börnstein, New Series III/22b, Springer (1989).

2D Materials: from Contact to Device Applications (P2)

Po-Wen Chiu^1,2

1Department of Electrical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan

2Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, 10617, Taiwan

Corresponding author e-mail: pwchiu@ee.nthu.edu.tw

ABSTRACT

Semiconducting layered materials show great promise as field-effect transistors (FETs) with device properties remarkably exceeding those of silicon when the vertical dimension is shrunken down to an atomic scale. Recent progress in such two-dimensional (2D) layered materials has facilitated the elucidation of their exotic electron transport properties and the developments of electronic

applications. Along with the developments come advancements in our understanding of how metal contacts affect the 2D device performance. A number of techniques has been employed to lower the contact barrier as well as to enhance the carrier mobility. For example, insertion of an oxide layer between the contact metal and 2D semiconductor can effectively unpin the Fermi level at the metal- semiconductor interface; deposition of a high- dielectric atop of the conduction channel can boost carrier mobility due to dielectric screening. In this talk, Fermi level pinning in 2D materials will be discussed. I will take InSe as an example and show that a proper treatment of the InSe surface can yield a record-high two-probe mobility of 423 cm2/V·s at room temperature and 1006 cm2/V·s at liquid nitrogen temperature without the use of h-BN encapsulation or high- dielectric screening.

Ultrahigh current on/off ratio of >108 and current density of 365 μA/μm can be readily achieved without elebrate engineering of drain/source contacts or gating technique. The high performance of InSe field-effect transistors with a thin layer of surface dry oxide is attributed to the effective unpinning of the Fermi level at the metal contacts, resulting in a low Schottky barrier. Applications for electronic and optoelectronic devices based on 2D materials will also be discussed.

New Paradigm of Nano Device - From More Moore to More than Moore (P3)

Wen-Kuan Yeh

Abstract

As MOSFETs are scaled down to 7nm and below, power consumption is the major limitation to maintain device performance well. Thus, how to suppress the device’s sub-threshold leakage and gate leakage is the key issue for sub-7nm MOSFET especially for high performance/lower power system. In order to scale MOSFET following Moore’s law continuously, there are some candidates are introduced to replace conventional MOSFET structure including FinFET, GAA transistor, and 2D material FET. This talk will explain semiconductor nano device trend and related advanced technology development especially for coming 7nm technology regime.

And other specific device for more than Moore application including sensor, energy harvesting device, and Monolithic IC for Internet on Thing (IoT) will be also explained.

Prepared nanomaterials for gaseous ozone and formaldehyde sensors (P4)

Ren-Jang Wu

Department of Applied Chemistry, Providence University, Taichung 43301, Taiwan, ROC

Several sensing technologies, including ultraviolet (UV) light absorption, amperometric detection and resistive detection methods have been employed to determine the gaseous ozone and formaldehyde concentration. Compared with above measurement techniques, the semiconductor type gas sensor presents tremendous potential of their low cost, high sensor response, ease of operation, and low power consumption. Nanomaterials were prepared for trace amount of gaseous ozone and formaldehyde sensor. The sensing materials were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and UV-Visible spectrophotometer. The fabricated sensing materials exhibited a high ozone and HCHO gas sensor response at room temperature. It also revealed ozone and HCHO sensor possessed good short term stability, and a possible sensing mechanism was proposed.

Prof. Ren-Jang Wu

Tel.: +886-4-26328001-15212;

fax: +886-4-26327554;

E-mail addresses: rjwu@pu.edu.tw

Self-assembled hetero-structure based on

two-dimensional transition metal dichalcogenides (P5)

K.Tsukagoshi

WPI-MANA, NIMS, Tsukuba, Japan

*E-mail : TSUKAGOSHI.Kazuhito@nims.go.jp

Growth of a uniform oxide film with a tunable thickness on two-dimensional transition metal dichalcogenides is of great importance for electronic and optoelectronic applications in next generation atomically-controlled hetero semiconducting structure. Here we demonstrate homogeneous surface oxidation of atomically thin WSe2 with a self-limiting thickness from single- to trilayers.

Exposure to ozone (O3) below 100 °C leads to the lateral growth of tungsten oxide selectively along selenium zigzag-edge orientations on WSe2. With further O3 exposure, the oxide regions coalesce and oxidation terminates leaving a uniform thickness oxide film on top of unoxidized WSe2. At higher temperatures, oxidation evolves in the layer-by-layer regime up to trilayers. The oxide films formed on WSe2 are nearly atomically flat. Using photoluminescence and Raman spectroscopy, we find that the underlying single-layer WSe2 is decoupled from the top oxide but hole-doped.

The hole-doping by the under-stoichiometric tungsten oxides (WOx with x < 3) grown on WSe2 can be used as both controlled charge transfer dopants and low-barrier contacts for p-type WSe2 transistors. WOx-covered WSe2 is highly hole-doped due to surface electron transfer from the underlying WSe2 to the high electron affinity WOx. The dopant concentration can be reduced by suppressing the electron affinity of WOx by air exposure, but exposure to O3 at room temperature leads to the recovery of the electron affinity. Hence, surface transfer doping with WOx is virtually controllable. Transistors based on WSe2 covered with WOx show only p-type conductions with orders of magnitude better on-current, on-off current ratio, and carrier mobility than without WOx, suggesting that the surface WOx serves as a p-type contact with a low hole Schottky barrier.

Our findings point to a simple and effective strategy for creating p-type devices based on two- dimensional transition metal dichalcogenides with controlled dopant concentrations.

References:

1. Self-limiting surface oxidation of atomically thin WSe2,

M.Yamamoto, S.Dutta, K. Wakabayashi, M. S. Fuhrer, K.Ueno, K.Tsukagoshi, Nano Letters 15, 2067–2073 (2015).

2. Surface Oxides on Single- and Few-layer WSe2 as Controlled Dopants and Low-Barrier Contacts, M.Yamamoto, S.Nakaharai, K.Ueno, K.Tsukagoshi, Nano Letters, 16, 2720–2727 (2016).

Engineering technologies for healthcare (P6)

Congo Tak-Shing Ching

Abstract

Engineering is significant not only in our daily life but also in healthcare. Medical communities have successfully applied engineering to healthcare diagnosis, monitoring and treatment. In this speech, the speaker cites his own research experiences in applying various engineering technologies in healthcare diagnosis, monitoring and treatment.

Bifacial Pb-Sb-S semiconductor solar cells from transparent copper selenide counter electrode (A1)

Nipapon Suriyawong(甄美英) and Ming-Way Lee(李明威) National Chung Hsing University

Bifacial solar cells are designed to allow light to enter from both sides, which have recently attracted many researchers. Meanwhile, Pb5Sb8S17 sensitized solar cells have been investigated in our lab with an efficiency of 2.5% for Pt counter electrode (CEs). In this work, we demonstrate bifacial Pb5Sb8S17 solar cells by using copper sulfide as CEs. Pb5Sb8S17 nanoparticle were deposited on the TiO2 electrode by using successive ionic layer adsorption reaction deposition (SILAR) method. The best solar cell yield maximal front and rear efficiencies of 2.32% and 1.12 % respectively. The preliminary results show that Cu-Se is a promising material for the construction of bifacial solar cells.

Resistive Switching Memory of Ga2O3 (A2)

Department of Physics, National Chung Hsing University, Email: s1012616@gmail.com

Abstract

The memory storage device has been playing a very important role in industry. To overcome the shortcomings of flash memories, four merging random access memories have showed up, resistive random access memory (RRAM) is one of the candidate. The device structure is simply an insulator material sandwiched between two metal electrodes, called the metal–insulator–metal (MIM) structure. [1-2] Meanwhile, RRAMs exhibit excellent properties, it offers sub-ns operation speed, low energy consumption and high endurance. Therefore, RRAMs are also a potential alternative to the current main memory. [2] For choosing interior material, binary oxides are the most abundant and show the best switching characteristics [3], and we chose gallium oxide (Ga2O3) in this topic.

Reference

[1] H.S.P. Wong, H.Y. Lee, S. Yu, Y.S. Chen, Y. Wu, P.S. Chen, B. Lee, F.T. Chen, M.J. Tsai,

“Metal–oxide RRAM,” Proc. IEEE., Vol. 100, No. 6, June 2012

[2] F. Pan, S. Gao, C. Chen, C. Song, F. Zeng, “Recent progress in resistive random access memories: Materials, switching mechanisms, and performance,” Mater. Sci. Eng., R 83, 1–59, 2014 [3] D. Y. Guo, Z. P. Wu, Y. H. An, P. G. Li, P. C. Wang, X. L. Chu, X. C. Guo, Y. S. Zhi, M. Lei, L. H. Li, and W. H. Tang, “Unipolar resistive switching behavior of amorphous gallium oxide thin films for nonvolatile memory applications,” Appl. Phys. Letters 106(4), 042105, 2015

鐵核金殼磁性奈米粒子增強法拉第磁光效應之特性研究及在阿茲海默症檢測之 應用 (A3)

a 陳建銘, a, b 吳秋賢, a, b 陳坤麟*

a 國立中興大學奈米科學研究所 b 國立中興大學物理學系

* E-mail : klchen@phys.nchu.edu.tw

Abstract

本研究以γ-Fe2O3 磁性奈米粒子為核心，利用迭代方法(Iteration method)將金奈米粒子 沉積在γ-Fe2O3 磁性奈米粒子表面上形成核殼結構(Core-Shell)之鐵核金殼磁性奈米粒子 (γ-Fe2O3@Au NPs)，從 X 光繞射(XRD)、吸收光譜(UV-vis)、超導量子干涉儀(SQUID)、雷 射粒徑分析儀(DLS)、穿透式電子顯微鏡(TEM)和能量色散 X-射線光譜(EDS)觀察形貌後確定 γ-Fe2O3 磁性奈米粒子的表面上有包覆金層。之後我們將鐵核金殼磁性奈米粒子應用在阿 茲海默症相關的 Tau 蛋白檢測，先把鐵核金殼磁性奈米粒子以官能基修飾，然後將 Tau 蛋白 之抗體(Anti-Tau)鍵結在金殼上，得到具有檢測阿茲海默症的鐵核金殼磁性奈米粒子試劑，

並且利用法拉第磁光系統檢測 Tau 蛋白不同濃度。由過去的成果已知，隨著抗原抗體的結合 過程中磁性奈米粒子會團聚形成較大的磁簇，而造成法拉第旋轉角的改變，利用葡聚醣包覆 磁性奈米粒子的檢測極限為 10 ng/ml (10 ppb)。在此次的實驗中我們利用鐵核金殼磁性奈 米粒子在特定波長(532 nm)下具有局部表面電漿共振(LSPR)特性與磁性奈米粒子相互作用，

使法拉第旋轉角變化量增強，大幅提升檢測靈敏度，其偵測極限可達到 1 pg/ml (1 ppt)。

此方法除了簡單方便，並且能即時監控結合過程，是未來極具發展潛力的阿茲海默症早期檢 測技術。

關鍵字:鐵核金殼磁性奈米粒子、磁光法拉第、阿茲海默症、Tau 蛋白.

Electro-optical characteristics of amorphous blue phase liquid crystal in different electrode structures (A4)

Yen-Wen Wang^1*, and Hui-Yu Chen²

1. Department of Physics , National Chung Hsing University,Taichung, Taiwan 2. Department of Physics, National Chung Hsing University, Taichung, Taiwan

Abstract

液晶是有秩序性介於液體與晶體之間，並且同是具有液體跟晶體的物理性質。而液晶 分子幾何異相性，在光學上具有複折射性，當兩道相互正交的線偏振光通過液晶時，會感受 到不同折射率。

藍相液晶是我們在液晶中加入適量的手徵性分子，使材料從均向態降溫到膽固醇相的過 程中，可以有機會形成螺旋軸正交的二維螺旋結構，此結構稱之為「雙股螺旋圓柱」。藍相 液晶從高溫到低溫分別是 BPIII、BPII 與 BPI 並展現不同於膽固醇相液晶與純液晶的光電特 性。

在實驗之中所使用的藍相液晶材料是在室溫測得的特性。電極結構下蓋為 IPS 電極，上 蓋為 ITO 導電層玻璃；不同以往 IPS 的結構。本實驗固定在低頻率下，在單邊的 IPS 和上蓋 的導電層接電，並且改變樣品的厚度去測量光電特性。從初步的實驗結果中，可以觀察到除 了 Kerr effect 以外的其他效應。

Qubit-3D Cavity Arrays for Realization of Circuit Quantum Electrodynamics (B1)

D. S. Dubyna,¹ Y. H. Jhang,¹ W. C. Chien,¹ Y. L. Hsieh,¹ and W. Kuo¹

1Department of Physics, National Chung Hsing University, Taichung, Taiwan

Abstract

Circuit quantum electrodynamics (cQED) studies light–matter interaction between an artificial atom (qubit) and electromagnetic waves that are propagating through a waveguide or waveguide cavity. The qubit-cavity system is a building block for quantum computer that requires an array of these elements coupled between each other. At the same time, qubit-cavity arrays could be used for making quantum simulators and studying non-linear quantum optical effects.

Thus, investigation of qubit-cavity arrays from the viewpoint of both practical application and fundamental physics is of high scientific relevance. As was shown in [1], the replacement of coplanar waveguide cavity by a superconducting three-dimensional (3D) cavity leads to a suppression of qubit decoherence and an increase of qubit lifetime. Therefore, research of qubit-3D cavity arrays is of particular interest.

In order to realize cQED experiments with qubit-3D cavity arrays, eigenmode simulations of coupled 3D cavities were done by using high frequency structural simulator (HFSS). 3D model for simulation consisted of from two to five 35×35×3 mm³ cuboids that were stacked one by one with 5 mm step and each cavity was coupled to its neighbor through a mutual hole (coupler). Locations of the coupler and qubit where the largest cavity-cavity and qubit-cavity coupling is expected were determined by changing coupler position in the structure. It was also found that for some normal modes of 3D cavity arrays, electrical field (E-field) inside the whole volume of some cavities is almost completely absent. This feature could be used in experiments of cQED for selective excitation or suppression of qubits in qubit-cavity arrays.

Taking into account results of HFSS simulations, aluminum 3D cavity array with changeable number of cavities was designed and fabricated. Dimensions of cavities in array are similar to those of simulated model and coupler diameter is equal to 8 mm. For generation and readout microwave signals, two SMA connectors in each edge cavity of the array were installed.

Measurement of S-parameters for 3D cavity array that consisted of five coupled cavities was done at the temperature of 50–60 mK. For the microwave signal which was transmitted between two edge cavities, resonances of all five normal modes were resolved while for the signal which was transmitted only in the edge cavity, resonance associated with the 1^st normal mode was absent. This behavior could be due to the weak E-field inside the edge cavity for the 1^st normal mode. The energy splitting between the 1^st and 5^th normal mode was equal to 83.5 MHz, which is consistent with results of HFSS eigenmode simulations that give 83.29 MHz splitting.

References

1. .H. Paik, D. I. Schuster, L. S. Bishop, G. Kirchmair, G. Catelani, A. P. Sears, B. R. Johnson, M. J. Reagor, L.

Frunzio, L. I. Glazman, S. M. Girvin, M. H. Devoret, and R. J. Schoelkopf, Phys. Rev. Lett. 107, 240501 (2011)

Surface plasma enhanced AC magnetization biosensor (B2)

Abstract

AC magnetization was a sensitive and non-destructive method of bio-moluculor measurement. Faraday coil could receive a small signal of sample magnetic changes. In past researchs, the applied AC magnetic field was set on the Brownine motion frequency of iron oxide nanoparticles. Antibody moluculors were coated on the surface as functional beads. Immune response of antibody and target antigen grab beads togeter and formated of larger aggregates. Becaues of brownian movement slows down, the frequency of induction magnetism was decleased. With the higher antigen concentration, the reunion action was more obviously. To measure the intensity inductive magnetic field on origenal frequency, and the concentration of antigen could be determined [Yang et al., 2014] .

In this study, a magnetism based bio-chip was practical of immune bio-sensor. Iron-oxide (Fe2O3) beads and gold nanoparticle was bounded on SiO2 wafer as layer by layer structure. For used the high biocompatibility of gold particles.

Gold particles was built as top surface, and anti-bodys was coated on. Silimer to the brownine motion mode of beads, particle – carbon chains provide a elasticity to vibrate and rotate for particels. This vibration model was controled by viscousty and elastic coefficient. ρ ∂v/∂t=-∇p+〖μ∇〗^2 v eq.1. v is the fluid velocity field, p is the fluid pressure, ρ is the fluid density, μ is the fluid shear viscosity, t is time, and ∇ is the spatial gradient operator [Chakraborty et al.

2013].

This bio-chip provide a high stability method to overcome the problem of the solution uniform and particle precipitation.

For the mesurement repeats, the the state of the film was stable. The bio-reagent cost was only 5 uL to cover the hole chip. As the larger touching surface, the reaction time was less than 1 mins. This system architecture had an extensive measurement of protein species. And it was easily to preserve and coat difference antibody by simply painted. We expected this measurement technique could work as a trace and rapid disease judged.

References

1. C. C. Yang, S. Y. Yang, C. S. Ho, J. F. Chang, B. H. Liu, and, K. W. Huang. J. Nanobiotech. 12:44 (2014).

2. J. A. Dagata, T. Inoue, J. Itoh, K. Matsumoto, and H. Yokoyama, J. Appl. Phys. 84, 6891 (1998).

3. S. L. McCarthy and J. Lambe, Appl. Phys. Lett. 30, 427 (1977).

Fig 1. SEM images of particle film Fig. 2. The magnetic susceptibility change with BSA concentratio

22

Fluorescence properties of 4-nm graphene quantum dots (B3)

Ying-Zuang Chien (錢盈庄)¹ and Tsong-Shin Lim (林宗欣)¹

1Department of Applied Physics, Tunghai University, Taichung, Taiwan

Abstract

Graphene quantum dots (GQDs) are a class of zerodimensional carbon materials and have attracted growing interest in recent years due to their low cost, processability, chemical stability, and photostability. The origin of the luminescence in these particles has been attributed to several mechanisms including excitons of carbon, emissive traps, quantum confinement effects, aromatic structures, oxygen containing groups, free zigzag sites, and edge defects [1]. Steady state spectra have consistently shown that the emission of bulk samples changes with the excitation wavelength [2]. Many reports attribute these optical properties to changes in energy levels that scale with the size of the GQD or doping of the GQD. Other studies propose that a single GQD particle contains multiple emissive states leading to the observation of excitation wavelength dependent emission in bulk samples [3]. A previous report of single particle fluorescence of graphene quantum dots with diameters ranging from 3 to 8 nm found that isolated single GQDs did not exhibit fluorescence at multiple wavelengths but did show multichromophoric behavior.This suggested that separate particles might be responsible for the emission at different excitation wavelengths rather than a single particle emitting at multiple wavelengths.

In this work we measured steady state spectra and time-resolved spectra of 4-nm GQDs. We found that emission spectra change with the excitation wavelength when the excitation wavelength is larger than 380 nm (Fig. 1). However, the fluorescence lifetimes of GQDs for different emission ranges are the same (Fig. 2). The result suggests that the fluorescence of the 4-nm GQDs is from merely one mechanism.

References

1. H. T. Li, Z. H. Kang, Y. Liu, S. T. Lee, J. Mater. Chem. 22, 24230 (2012).

2. C. M. Luk, B. L. Chen, K. S. Teng, L. B. Tang, S. P. Lau, J. Mater. Chem. C 2, 4526 (2014).

3. L. B. Tang, R. B. Ji, X. M. Li, G. X. Bai, C. P. Liu, J. H. Hao, J. Y. Lin, H. X. Jiang, K. S. Teng, Z. B. Yang, ACS Nano 8, 6312 (2014).

400 500 600 700 800

-100 0 100 200 300 400 500 600 700 800

PL

Wavelength (nm) 400 420 440 460 480

0 500 1000 1500 2000 2500

0.1 1

Intensity (a.u.)

Time (ps)

380-420 nm 410-450 nm 440-480 nm 470-510 nm

Figure 1. Emission spectra of 4-nm GQDs excited with different wavelengths.

Figure 2. Fluorescence decay curves of 4- nm GQDs for different emission ranges.

23

Synthesis and Optical Characterization of CuIn1-xGaxSe2 Nanocrystals (B4)

蔡有慶 You-Ching Tsai¹,洪英晢 Ying-Jhe Hong²,羅仁傑 Jen-Cheh Lo¹,石豫臺 Yu-Tai Shih ^2*

1Department of Physics, National Changhua University of Education, Changhua, Taiwan

2Graduate Institute of Photonics, National Changhua University of Education, Changhua, Taiwan

*E-mail: ytshih@cc.ncue.edu.tw abstract

CuIn1-xGaxSe2 nanocrystals (NCs) were synthesized. Band gap of the NCs was adjusted by varying the mole fraction x. Absorption, Raman, and X-ray diffraction measurements were taken to investigate the properties of the NCs. The dependence of optical properties of the NCs on the the mole fraction x was investigated.

24

Metabolism and Electrical Properties of Silver Nanoparticles on the NIH-3T3 Cells (B5)

國立中興大學 物理所 黃雅琦 指導教授:何孟書

現今奈米科技發達，各種奈米粒子已應用在各式生活產品上，為了解這類 奈米粒子對於人體的潛在危害，本研究使用銀奈米粒子為主要實驗材料，利用 對環境相對靈敏的 NIH-3T3 纖維母細胞作為正常細胞的代表，探討加入銀奈米 粒子前後對於細胞毒性以及機械性質的影響，並設計一款結構簡單之生物基板，

預期可以利用此基板作細胞的電性量測，將取得細胞的電訊號作為生物檢測的 標的。

第一部分利用光學顯微鏡與細胞計數，觀察到銀奈米粒子的加入會抑制細 胞成長，使細胞成長密度較稀疏，細胞成長率僅占正常細胞的 60~80 %。

第二部份在液態下利用 AFM 的 QNM 模式取得細胞的機械應力，研究加入銀 奈米粒子後細胞核與細胞突觸的高度、黏滯力以及細胞韌性變化，觀察到銀奈 米粒子會造成細胞高度上升，黏滯力與細胞韌性也有增加的現象，其中以細胞 突觸影響最為明顯，結果顯示銀奈米粒子的加入會造成細胞結構上的影響使細 胞機械性質改變。

第三部分利用螢光染色研究細胞的肌動蛋白再銀奈米粒子加入後對細胞型 態的影響，結果顯示加入奈米粒子後細胞突觸無法延展，整體的細胞形態較正 常細胞萎縮，証明奈米粒子的加入會影響細胞型態的表現。

最後我們已成功製作含有金柱之生物基板，並成功使細胞成長於基板上方，

利用探針接觸電極與細胞溶液建構完整之電性量測系統，取得細胞的電性 I-V 訊號。

25

Figure 1. The reflectance curves of polished Si and all ZnO samples at normal incidence. The insets are the pictures of (a) sample A (as-grown ZnO-NPs), (b) sample B, (c) sample C, (d) sample D and (e) sample E on 6-inch wafer, respectively.

Broadband omnidirectional light trapping in gold-decorated ZnO nanopillar arrays

Yuan-Ming Chang (張原銘), and Yen-Fu Lin (林彥甫)

Department of Physics, National Chung Hsing University, Taichung 402, Taiwan

Abstract

The Photoluminescence (PL) and reflectivity characteristics of zinc oxide nanopillars (ZnO-NPs) grown on indium-tin-oxide (ITO)-coated glasses were investigated. The room temperature PL showed bright white-light emission for the undoped ZnO-NPs grown at 600 °C, suggesting the close relation between the optical characteristic and the growth conditions being carried out for obtaining the present ZnO-NPs. The reflectivity of the as-grown ZnO-NPs array was about ~29 % with the wavelength of the incident light ranging from 200-1800 nm. Nevertheless, the reflectance reduced significantly to less than 9.9 % when a layer of gold (Au) was deposited on ZnO-NPs by sputtering for 5 minutes, corresponding to more than 65% reduction in Au-coated ZnO-NPs (Au/ZnO-NPs). Moreover, the angle-resolved reflectance measurements on the present Au/ZnO-NPs array show an omnidirectional light-trapping characteristic. These remarkable characteristics, broadband and omnidirectional light- trapping of Au/ZnO-NPs, are attributed to the extended effective optical path of the incident light due to sub-wavelength scattering resulting from the presence of Au nanoparticles.

References

4. J. Wang, X. Li, Y. Xia, S. Komarneni, H. Chen, J. Xu, L. Xiang,and D. Xie, ACS Appl. Mater.

Interfaces 8, 8600 (2016).

5. Y.-M. Chang, J. Shieh, P.-Y. Chu, H.-Y. Lee, C.-M. Lin, and J.-Y. Juang, ACS Appl. Mater.

Interfaces 3, 4415 (2011)

6. Y.-M. Chang, M.-C. Liu, P.-H. Kao, C.-M. Lin, H.-Y. Lee, and J.-Y. Juang, ACS Appl. Mater.

Interfaces 4, 1411 (2012)

26

可電控之介電質覆蓋石墨烯方向耦合波導 (C2)

孫德嘉 Abstract

這是一個運作在中紅外線波長之可調的電漿子波導方向耦合器。此元件 之工作波長為 10.5μm，由覆蓋在石墨烯上的兩個前端長直，後端 s 型且互相 平行、對稱的介電質波導所組成。在固定波導長度下，藉由改變石墨烯的費米 能級來控制從輸入波導耦合至另一平行波導的能量耦合長度，達到一個可控制 的方向耦合效果。

Fast electro-optic switching in Liquid Crystal blue phase II (C3)

1. Department of Physics, National Chung Hsing University, Taichung, Taiwan

Abstract

The liquid crystal (LC) blue phase (BP) is a special phase between isotropic phase and cholesteric phase.From high to low temperature,there are three different BPs : BPIII, BPII, and BPI. The temperature ranges where a pure simple-cubic blue phase (BPII) emerges are quite narrow compared to the body-centered-cubic BP (BPI).It caused the study of BPII were far less than BPI.

In our study, the temperature range of BPII are 8°C, By increasing a vertical electric field, the reflected wavelength of the blue phase can be shifted to a longer wavelength in a range of 50 nm within a few ms.

14 16 18 20 22 24 26 28 30 32 34 36 400

420 440 460 480 500 520 540 560

Wavelength (nm)

Temperture ( ^oC)

Cooling Process Heating Process

350 400 450 500 550 600 650 700 0

500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000

Light Intensity (Counts)

Wavelength (nm)

0V 20V 40V 60V 80V 100V 120V 140V 160V 180V 200V 220V 240V

Fig 1. Temperature dependence of the reflection wavelength of the sample.

Fig 2. Measured reflectance spectra of the BPII sample at different voltages at 32°C^.

27

不同鍛燒溫度的碳膠在染料敏化電池對電極之研究(C4)

Guan-You Lin

In this reporter we have demonstrated the photovoltaic performance of dye- sensitized solar cells with low-cost carbon paste (CP) based counter electrodes. With sintering CP at 300 °C, the overall conversion efficiency of cells can reach 4.9%, which is comparable to 5.7% of the cells with counter electrode of platinum. After sintering, crystalline quality of CP was improved, resulting in the decrease of series resistance of cells and the increase of the work function of CP. We also showed that the reduction rate of triiodide is significantly enhanced due to the increase of surface area of CP and the energy matching between the reduction potential of triiodide and the work function of CP.

28

Fabrication and characterization of magnetic field sensors using giant magnetoresistance devices (D1)

S.Z. Ciou¹(邱聖哲), G.H. Lai¹ (賴國豪), H.C. Han¹(韓鴻騏) and J. C. Wu^1*(吳仲卿)

1Department of Physics, National Changhua University of education, Changhua 500, Taiwan

*e-mail: phjcwu@cc.ncue.edu.tw

For last two decades or so, giant magnetoresistance^[1] (GMR) materials have been mainly adopted in sensing very weak magnetic field, such as GMR read head used in hard disk since 1997. Recently, GMR sensors have even attracted intensive studies for the understanding of the fundamental physics and thus improving the MR ratio. Very much attention has been paid to a potential application of the geomagnetic field sensor for many portable devices in probing position and orientation. In this report, we are presenting a study of making GMR sensors with current-perpendicular-to-plane (CPP) and current-in-plane (CIP) configurations, respectively, and characterizing the corresponding transfer curves. First of all, multilayer structure of Ta(3) / NiFe(2) / PtMn(15) / CoFe(2.5) / Ru(0.8) / CoFe(3) / Cu(2) / Co(1.5) / NiFe(2.5) / Cu(0.6) / Ta(10) (numbers are nominal thicknesses in nanometers) are grown on a SiO2-coated silicon wafer by using an ultrahigh vacuum sputtering system and the sheet film MR curve is measured, as shown in Fig.1. A top-down process was then used in making micrometer-scale sensor cells having CPP and CIP configurations. The dimension of the sensor cells are designed to be 3x3, 3x6, 3x9, and 3x12 µm2, respectively. Notice that the biasing direction is designed to be along the short axis direction of the cell, in such a way the easy axis of magnetization in the free layer is along the long axis direction owing to shape anisotropy. As a consequence, a linear transfer curve is then obtained. Details of the device fabrication and transfer curve characterization will be elaborated.

-1000 -800-600 -400 -200 0 200 400 600 800 1000 4.8

4.9 5.0 5.1 5.2

R

R(Ohm)

H(Oe)

Fig.1 GMR film stack is shown on the left and the corresponding MR curve of sheet film is shown on the right. Note that the MR ratio is up to nearly 9%.

References:

[1] A.Johnson, Diss., University Darmstadt, Germany, 2003

29

極短之混和表面電漿子極化光分離器設計(D2) Yu-Chun Wu

Abstract

我們設計出一種混和表面電漿子的極化光分離器，目前僅需 685 奈米的長 度，就可以使 TM 和 TE 波分離。其中 TM 的消光比達到 21.55dB，TE 也有 17.74dB，分離效能很高，可以有效實現高度密集的積體光路。而 TM 插入損耗 只有 0.46dB，TE 插入損耗為 0.71dB，損耗相當低。故此設計可以實現低損耗，

高效能的極化光分離器。’

Strain sensor base on gold nanoparticles (D3)

Wei Chang^c, Shien-Der Tzeng^d and Watson Kuo^a*

aDepartment of Physics, National Chung Hsing University

bDepartment of Materials Science and Engineering, National Chung Hsing University, cCenter for Condensed Matter Sciences, National Taiwan University,

dDepartment of Physics, National Dong Hwa University,

Abstract

Gold nanopaticle (AuNP) films have been shown to exhibit novel electric, plasmonic and photoelectric properties for wide applications, such as surface enhance raman scattering in biosensor and absorption spectrum in Environment sensor etc. In this study, we propose to develop a high-sensitive, low-cost and portable stress sensing technology. For this aim, AuNPs were

self-assembled on flexible substrates, forming closely packed multilayer films by centrifugal method, followed by appropriate chip packaging technique.

For better electric conduction, AuNPs were modified with 3-mercaptopropionic acid, which has a length of about 0.9nm. As such the typical resistance of our sensors are in the range of 3-20 kΩ. When strains are applied to the substrate, the distance between adjacent AuNPs is changed, inducing the variations on the device resistance and capacitance. Experiment result show that our sensors may have the gauge factor up to 150 and the capacitance change is typical 10-20 pF under a strain of 0.5%.

To study the response time, sensors were tested under mechanical vibrations of different frequency. The resistance change can be clearly identified up to a frequency of 30 Hz. With a high frequency response, the sensors can find theirs applications in human pulse sensing, motion detection, and even voiceprint recognition.

30

The charge transport excited by surface acoustic wave in mechanically exfoliated graphene (D4)

Yu-Te Wu , Yen-Yang Liu, Chien-Han Chen, Cen-Shawn Wu, Yen-Fu Lin and Watson Kuo

Department of Physics, National Chung Hsing University, Taichung, Taiwan National Changhua University of Education, Changhua, Taiwan

We investigate how the surface acoustic wave (SAW) affects the charge transport in the mechanically exfoliated graphene . In general, SAW generates a pronounced dc current in graphene because of its monolayer geometry and large mobility. Our devices are fabricated on 128°Y-X cut lithium niobate substrate. SAWs are detected and generated by two interdigit transducers, which consists of 20 pairs of thermally evaporated Cr/Au electrodes. The width of the electrode is 2 μm, corresponding to a resonance frequency of 100 MHz, which is confirmed by measurement of microwave reflection and transmission. The graphene sheet is exfoliated mechanically and transferred from PDMS ( Polydimethylsiloxane ) to the lithium niobate substrate with the alignment under an optical microscope .

Electrodes for transport measurement are fabricated by standard electron beam lithography and following-up thermal evaporation. Our fabrication scheme can also be applied to other two-dimensional materials for investigating their properties.

31

Performances of Cd-Sb-S

semiconductor-sensitized solar cell (Po1)

Advisor: Prof. Ming-Way Lee Abstract

We present a new ternary semiconductor nanoparticle sensitizer cadmium antimony sulfide (Cd-Sb-S) for liquid junction sensitized solar cells. Cd-Sb-S nanoparticles were grown using a two-stage successive ionic layer absorption and reaction (SILAR) process. First, Cd-S were grown on the surface of a nanoporous titaniumdioxide (TiO2) electrode. Second, a Sb-S nanoparticles were grown on top the Cd-S layer. The optimal number of SILAR cycles are 4 and 6 cycles for Cd-S and Sb-S, respectively. The double-layered was transformed into Cd-Sb-S nanoparticles after annealing at 350◌ ֩C for 1 hour in N2 atmosphere, the counter electrode was Au.

The best cell yielded a PCE of 1.81% , a JSC of 11.77 mA/cm2, a VOC of 0.41 volt and FF of 37.62% under AM1.5. The ZnS passivation reduced charge recombination and improved the PCE to 1.98%, which is ~10% higher than the cells without passivation. We can improve photovoltaic performances by using ZnSe passivation and reduced the light intensity.

32

Modulation efficiency in scanning capacitance microscopy for imaging hole concentration distribution in silicon (Po2)

Lin^1,3

1Department of Physics, National Chung Hsing University, Taichung, 402, Taiwan

2National Nano Device Laboratories, NARL, Hsinchu, 300, Taiwan

3Institute of Nanoscience, National Chung Hsing University, Taichung, 402, Taiwan

Abatract

For cross-sectional scanning capacitance microscopy (SCM), it is very difficult to prepare an SCM specimen by standard semiconductor processes due to the tiny geometric volume. Prior studies on n-type silicon have revealed that modulation efficiency (ME) in SCM is an important indicator, which may represent the quality of contact electrodes and mainly influence dC/dV signal intensity. silver silicide as a contact electrode obviously enhanced the ME up to 2.7. However, the typical value of the ME for p-type silicon is much lower than 2.7. For this reason, we investigated the contact electrode and the ME for imaging hole concentration distribution in p-type silicon. In this work, we used various contact electrodes, which have different work functions, to measure the ME and imaged hole concentration distribution.

Experimental results showed that a gold nano-film as a contact electrode in SCM results in an ME up to 2.4. While using silver glue and silver silicide as contact electrodes, the ME values are down to 1.3, respectively. For the depth profile of hole concentration, the sectional analyses of SCM images also revealed that the improvement of the ME enhances the SCM resolving power on hole concentration.

33

Establishment of exchange bias coupling in Fe/MgO(001) ferromagnet/oxide system (Po3)

C. J. Chen (陳家儒)¹, K. Lin (林凱) ¹, J. J. Li(李金磚) ¹, M. S. Tsai (蔡明憲)¹, J. Y. Ning (甯敬宇) ¹, J.

Y. Xu (許峻耀) ¹, J. Y. Lee (李潔瀅) ¹, S. C. Weng (翁世璋)², and B. Y. Wang (王柏堯)^1,*

1Department of Physics, National Changhua University of Education, Changhua 500, Taiwan

2National Synchrotron Radiation Research Center, Hsinchu 300, Taiwan

*Email: bywang1735@cc.ncue.edu.tw

Abstract

The exchange bias phenomenon occurred in antiferromagnetic/ferromagnetic (AFM/FM) systems is known to be essential for a stabilization of magnetization of reference layer in magnetic tunnel junctions (MTJs). In this work, by carefully controlling the film thickness and annealing temperature, we determined that an exchange bias field can be established in Fe/MgO(001) FM/oxide systems. X-ray absorption near-edge structure provides direct evidence indicating a formation of FeO in Fe/MgO(001) films upon high temperature annealing. The high thermal stability of the exchange bias coupling in the annealed Fe/MgO(001) could be attributed an enhanced Néel temperature of the AFM FeO when they are embedded into the FM matrix.

34

Influence of the contact electrode on scanning capacitance spectroscopy (Po4)

Chun-Hsien Liu¹, Jhih-Yang Chen¹, Yao-Jen Lee^{1, 3}, and Mao-Nan Chang^{1, 2}

1Department of Physics, National Chung Hsing University, Taichung, 402, Taiwan 2Institute of Nanoscience, National Chung Hsing University, Taichung, 402, Taiwan

3National Nano Device Laboratories, NARL, Hsinchu, 300, Taiwan

Scanning capacitance spectroscopy (SCS) extended from scanning capacitance microscopy (SCM) provides flat-band voltage shifts (△VFB) and has been widely used to characterize dielectric layers for the developments of electronic materials and devices. The full width at half maximum in an SCS profile is also an indicator of interface traps. Prior works revealed that the SCM image quality depends on the specimen contact electrodes. It is then natural to question whether the contact electrodes also influence SCS profiles. For studying the influence of the contact electrode on SCS, we used three types of contact electrodes in this work, including silver glue, silver film, and silver silicide. It was revealed that the contact electrode may induce series capacitance and interface traps, which contribute to the measured

△VFB and distort SCS profiles. According to SCS analyses, the contact electrode using silver silicide minimized the interface traps and the △VFB, being consistent with the prior studies in SCM.

35

Ion exchange-prepared PbSbSe nanoparticles:A new solar absorber material for quantum dots-sensitized solar cell

(Po5)

CING-RU JIANG(蔣青儒) and Ming-Way Lee(李明威) Abstract

We report a new ternary solar absorber material “Pb-Sb-Se” for solar cells.

PbSbSe nanoparticles (NPs) have been prepared from a Pb-Sb-S precursor by the solution-based Se anion exchange reaction. The Pb-Sb-S precursor was grown on a TiO2 electrode using the successive ionic layer adsorption and reaction (SILAR) method. Liquid-junction Pb-Sb-Se quantum dot-sensitized solar cells (QDSSCs) were fabricated from the synthesized Pb-Sb-Se for the first time. The best cell, prepared using the Pt counter electrode and the polysulfide electrolyte, yielded an efficiency of 0.37%, a normalized short current density (Jsc) of -4.52mA/cm2, an open-circuit voltage (Voc) of 0.24V and a fill factor (FF) of 33.85%.

36

生物功能性鐵核金殼磁性奈米粒子合成與特性研究 (Po6)

a林怡馨, ^a陳建銘, ^{a, b}吳秋賢, ^{a, b}陳坤麟*

a 國立中興大學奈米科學研究所

b 國立中興大學物理學系

* E-mail : klchen@phys.nchu.edu.tw

Abstract

根據文獻指出γ-Fe2O3 磁性奈米粒子上包覆金層在特定波長下具有局部 表面電漿共振，金有較佳的化學穩定性及生物相容性容易與生物分子鍵結，塗 覆金層可減少磁性奈米粒子的氧化，又因奈米金表面容易與硫醇基(Thiol Group)形成 Au-S 鍵，可增加化學穩定性因此可以做為理想的檢測試劑。本研究 使用共沉澱法合成 Fe3O4 磁性奈米粒子，再以硝酸加熱氧化成γ-Fe2O3 磁性奈 米粒子，最後利用迭代(Iteration method)將金沉積在γ-Fe2O3 磁性奈米粒子 表面上形成以γ-Fe2O3 為核心(core)金為殼層(shell)結構之鐵核金殼磁性奈 米粒子(γ-Fe2O3@Au NPs)，從 X 光繞射(XRD)、吸收光譜(UV-vis)、穿透式電 子顯微鏡(TEM)、超導量子干涉儀(SQUID)、雷射粒徑分析儀(DLS)對其形貌、光 學性質做定性分析，確定磁性奈米粒子的表面上有包覆金層。之後我們將鐵核 金殼磁性奈米粒子應用在阿茲海默相關的 tau 蛋白檢測，先把鐵核金殼磁性奈 米粒子以官能基修飾，然後將 Tau 蛋白之抗體(Anti-Tau)鍵結在金殼上，得到 具有檢測阿茲海默症的鐵核金殼磁性奈米粒子試劑，我們會利用拉曼光譜 (Raman spectrum)來確認 Anti-Tau 成功鍵結於鐵核金殼磁性奈米粒子之表面，

形成阿茲海默症的檢測試劑。

37

Controlling antiferromagnet-induced perpendicular magnetic anisotropy with magnetic proximity effects from in-plane magnetic

ultrathin films (Po7)

Chun-Wei Huang (黃俊瑋)¹, Ming-Shian Tsai (蔡明憲)¹, Kai, Lin(林凱)¹, Chun-Chieh, Chung(鍾俊 傑)¹, Chun-I Lu (呂俊毅)², Der-Hsin Wei (魏德新)², and Bo-Yao Wang (王柏堯)¹*.

1Department of Physics, National Changhua University of Education, Changhua 500, Taiwan

2National Synchrotron Radiation Research Center, Hsinchu 300, Taiwan

* E-mail: bywang1735@cc.ncue.edu.tw

Abstract

In this study, the magnetic proximity effects on the antiferromagnet-induced perpendicular magnetic anisotropy (PMA) were investigated in 12 ML Ni/2 ML Co/0-12 ML Mn/2-5 ML Co/Cu(100) ultrathin films. The samples were grown and measured in-situ in an ultrahigh-vacuum preparation chamber with a base pressure of 2 × 10⁻¹⁰Torr. The magnetic anisotropy of the 12 ML Ni/Co/Mn/Co films is found to be changed from in-plane to out-of-plane direction as the thickness of Mn film (tMn) is larger than a critical value. Significantly enhanced perpendicular magnetic anisotropy (PMA) of top 12 ML Ni/Co films was also observed when increases the thickness of the bottom Co film with in-plane magnetic anisotropy, and such a phenomenon is found to approach saturation when tMn reaches 12 ML.

Imaging of x-ray photoemission electron microscopy on 12 ML Ni/Co/Mn/wedged-Co films clearly shows that the size of induced perpendicular magnetic domains is modulated by a variation of bottom Co film from interger to half-integer thickness. These results clearly show that the induced PMA in 12 ML Ni/Co/Mn/Co films is sensitive to the magnetic proximity effects from the bottom in-plane magnetic ultrathin Co films, where the AFM ordering of Mn film could be modulated by the interface roughness as well as the Curie temperature owing to the finite size effects of low dimensional magnetic materials.

This project is financially sponsored by the Ministry of Science and Technology, Taiwan (Grant No.

MOST 105-2112-M-018 -001 -MY3).

---

Key word ： Magnetic proximity effects, Perpendicular magnetic anisotropy (PMA), Curie temperature (Tc)

38

Vortex Chirality in Permalloy films with Asymmetric Disk Arrays using a MOKE Microscope (Po8)

Chin-Han Su¹, Deng-Shiang Shiu¹, Yun Hong¹, Kao-Fan Lai¹, Jong-Ching Wu¹, Lance Horng^1*

1Department of Physics, National Changhua University of Education, Changhua, Taiwan

*e-mail: phlhorng@cc.ncue.edu.tw Absrtact

Here, we investigated probability of vortex chirality by changing array spaces for varying the stray field. Pattern transfer and deposition employed lift-off and magneton sputtering, the asymmetric disk diameter and thickness about 2 μm, 20 nm respectively. We adjusted spaces of array(D) about 4, 2, and 0.4 μm as experimental variable, as shown on figure 1. We measured each variable remanet sate 5~10 times. The measurement was done by MOKE microscope. During measurement, we applied suitable magnitude of field along y-axis (long black arrow in figure 1). Then switched off field to measure chirality of each device by Kerr image. In the image, bright and dark means the different directions of domain, as shown by color bar on figure 1. The chirality of vortex can be seen on inset of figure 1. We counted the number of appeared chirality (clockwise and counter clockwise) on each magnetic for analysing probability of appearance. In this study, we found the probability will change by adjusting D. The largest value D has 33% probability to appear of clockwise(cw) vortex, moderate value provide D appear less probability of cw vortex, and the shortest value D has 77% probability to appear cw vortex. The bigger device has larger area to allow moment rotation. That means vortex chirality in array influence through chaos effect (such as thermal and imperfect field operating). The chaos effect influence can control by adjusting D for vortex magnetic device application.

Key word: Magnetic vortex, asymmetric magnetic disk.

Figure 1.Color bar shows bright and black arrow for different direction of magnetization. This image is measured by MOKE microscope in negative saturation. The spaces distance marked in D. The field applied alone y-axis.

Inset is magnetic image of remanence after directly switched off field.

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