To study the effect of lattice strain on the transition in the Al2O3 growth mode, we used XRD to study the variation in lattice constants of the anatase and rutile layers as a function of the ALD reaction cycle. The XRD samples were prepared by depositing separately the anatase and the rutile layers on two different FTO glass substrates. Figure 6.4 shows the XRD spectra of the two samples over a scan range from 24 to 28o. The Bragg’s angles of the (101) plane of standard anatase (JCPDS Card Number 21-1272) and the (110) plane of standard rutile (JCPDS Card Number 21-1276) are also provided as marked by the vertical dashed-dotted lines. When the thickness of the Al2O3 overlayers increased, the (101) diffraction peaks for the anatase sample shifted to lower angles, whereas the (110) diffraction peaks for the rutile sample remained unchanged. The diffraction peaks for both samples were located at higher angles than those of the standard samples, suggesting that the TiO2 lattice might suffer from the stress of contraction. Table 6-2 lists the lattice constants and lattice volumes of the TiO2 particles with respect to the number of the ALD Al2O3 deposition cycle.
The lattice constant a of the anatase nanocrystals remained almost unchanged through the 30 cycles of ALD deposition, whereas the lattice constant c increased with the cycle number.
Figure 6.4 XRD spectra of the anatase electrode layer (a) and the rutile electrode layer (b) with respect to the number of ALD deposition cycles of the Al2O3overlayer.
Table 6-2 Lattice constants and lattice volumes of TiO2 electrodes for various numbers of ALD Al2O3 deposition cycles.
Sample
134.3 134.9 135.0 135.3 135.4 135.5 135.7 Lattice
62.0 61.9 62.1 61.9 62.1 62.0 62.0
Based on the lattice constants derived from the XRD data, the lattice volume of the anatase and the rutile crystals as a function of the ALD cycle number is shown in Figure 6.5.
The standard lattice volumes of the anatase and rutile phases (JCPDS data) are also provided as marked by the horizontal dashed-dotted lines. For the rutile electrode layer, the lattice volume varies little with respect to the ALD cycle number. On the other hand, the lattice volume of the anatase electrode layer increases with increasing the ALD cycle number until a saturated volume is reached at the 15th ALD reaction cycle. The difference between the saturated lattice volume of the anatase and rutile layers and the lattice volume of the corresponding standard TiO2 phases can be attributed to the contractive stress induced by the oxygen deficiency of the TiO2 particles [105~ 107]. Observing a large contractive strain in TiO2anatase nanocrystals, Li et al. [108] suggested that extensive surface hydration forming Ti-OH surface species was the primary reason why the anatase nanocrystals had a smaller lattice volume than their bulk phase. Likewise, in this study, Ti-OH surface groups on the as-prepared TiO2 nanoparticles can induce lattice contraction in the nanoparticles. The island growth of the Al2O3 overlayer on the TiO2 nanoparticles at the initial stage of the ALD deposition can be attributed to the large lattice strain as discussed above. The amount of the Ti-OH species on the anatase nanoparticles can be reduced through the ALD Al2O3 deposition, which produces Ti-O-Al(OH)2 surface groups as described in Eq. (2-5). As a result, the strain energy of the anatase TiO2 nanocrystals decreases upon increasing the number of the Al2O3
deposition cycle, leading to a transition from island growth to layer-by-layer growth, as revealed by Fig. 6.3. The large difference in the dependence of the lattice volume on the ALD cycle number between the anatase and the rutile electrode layers can be ascribed to the large difference in the surface to volume ratio. The contractive surface stress should primarily affect the surface lattice of a few atomic layers and, therefore, particles of larger size must have a smaller lattice contraction in the particles. Because the anatase nanoparticles have a
much smaller size (~20 nm) than the rutile particles (~200-400 nm), the surface hydration produces a larger surface stress on the anatase nanoparticles. In addition to the difference in the growth mode transition between the two TiO2 electrode layers, the lattice contraction may also affect the ALD-Al2O3 deposition rate on the two layers. As discussed above, the Al2O3
deposition rate on the anatase layer is much smaller than that on the rutile layer before the tenth ALD cycle. Compared with the rutile particles, the anatase nanoparticles have a much larger contractive strain during the first few cycles of the ALD deposition, implying that the first few atomic layers of Al2O3 on the anatase nanoparticles are subject to a higher stress, and thus the deposition of these highly stressed atomic layers is energetically unfavorable. As a result, the ALD reaction rate is slower on the anatase nanoparticle than on the rutile particles, leading to a smaller Al2O3 deposition rate on the anatase electrode layer.
Figure 6.5 Lattice volumes of TiO2 crystals in (a) the anatase and (b) in the rutile electrode layers, plotted with respect to the number of ALD reaction cycles of the Al2O3overlayer.
According to our previous study, the DSSCs using the porous TiO2 electrodes had a maximum PCE (6.6%) when the anatase nanoparticles was coated by the Al2O3 overlayer with a coverage of 0.25, which was achieved after the first ALD deposition cycle. The cause of the low coverage was ascribed to a result of the prevailing island growth mode during the ALD deposition. Island growth of the Al2O3 overlayer resulted in a low coverage and a non-uniform thickness of the overlayer, and thus greatly degraded the PCE of the DSSCs.
Because the contractive strain increases with decreasing the size of TiO2 particles, it is likely that we can obtain a better PCE for the DSSCs featuring the porous TiO2 electrode if the size of the anatase nanoparticle is properly increased. When the size of the anatase nanoparticles is correctly chosen to minimize the surface contractive strain, we may obtain a uniform Al2O3
overlayer of higher coverage on the anatase electrode during the first ALD cycles, and thereby the DSSCs may exhibit a much better PCE performance compared with those using the present electrode structure featuring anatase nanoparticle of ~20 nm in size.
6.4 Summary
We have used a low-temperature (150°C) ALD process to grow ultra-thin Al2O3
overlayers on TiO2 electrodes in dye-sensitized solar cells. Island growth on the anatase layers was more pronounced than on the rutile layers at the initial deposition stage, and layer-by-layer growth replaced island growth to become the main growth mode after the 5th ALD cycle. The origin of the island growth process is ascribed to the presence of the high surface stress resulting from surface hydration on the TiO2 nanoparticle at the beginning of the ALD Al2O3 deposition. The island growth resulted in a non-uniform ALD Al2O3
overlayer of low coverage on the nanoporous TiO2 electrodes during the first few ALD
reaction cycles. The study suggests that a better PCE of the DSSCs may be obtained if the size of anatase nanoparticles of the DSSC electrodes can be correctly chosen to minimize the surface lattice strain.
Chapter 7
Conclusions and Future Works
7.1 Conclusions
Ultra-thin Al2O3 films were deposited on nanoporous TiO2 electrodes of dye-sensitized solar cells (DSSCs) by atomic-layer-deposition (ALD). The power conversion efficiency (PCE) of the DSSCs increases from 5.75% to 6.5%, an improvement of 13%, when the Al2O3
overlayer reaches an average thickness of ~0.2 nm. We investigated the energy level, surface coverage and growth mode of the ALD-Al2O3 overlayer on the core/shell electrodes and concluded the results as follows.
a. The formation of Ti-O-Al(OH)2 and interfacial dipole layers exhibited a strong influence on the work function of the Al2O3 overlayers, while the thicker Al2O3
overlayers caused the values of valence band maximum and band gap to approach the values associated with pure Al2O3.
b. A work function difference of 0.4 eV and a recombination barrier height of 0.1 eV were associated with the highest PCE achieved by the first monolayer of Al2O3
layer. Thicker Al2O3overlayers, however, caused significant reduction of PCE with negative and increased interfacial energy barrier height between the N719 dyes and TiO2 electrodes.
c. We found that the paths of electron transfer from dye into TiO2 without any energy barrier and therefore improve the cells PCE due to the proper ultra-thin Al2O3
energy levels. The PCE of the DSSCs may correlates with work function difference, recombination barrier height, and interfacial barrier height resulting from various thicknesses of the Al2O3 overlayers and that interfacial reactions, such as the
formation of Ti-O-Al(OH)2 and dipole layers, play an important role in determining the interfacial energy levels required to achieve optimal performance of dye-sensitized TiO2 solar cells.
d. We established a core/shell (C/S) model which evaluates the surface coverage of an overlayer deposited on nanoparticles in terms of X-ray photoelectron spectroscopy signals of the nanoparticles. We used the model to estimate the coverage of Al2O3
shell layers, which were deposited on the nanoporous TiO2 electrodes of dye sensitized solar cells (DSSCs) by atomic layer deposition (ALD), as a function of the number of ALD reaction cycles.
e. The coverage increased from 0.25 to 1.0 upon increasing the thickness of the Al2O3
shell layers, indicating the ALD-Al2O3 deposition on the nanoporous electrode was via the island growth mode.
f. On the basis of the coverage analysis, we predict that improvement in the PCE of
~52% is obtainable when a single monolayer of ALD-Al2O3(i.e. at the coverage of 1.0) deposited on the nanoporous TiO2 electrode.
g. The growth mode of the ALD-Al2O3 overlayers is changed from island growth to layer-by-layer growth after the first 5 ALD reaction cycles, and the growth mode transition is much more pronounced for the anatase electrode layer.
h. We suggest that the growth transition of ALD-Al2O3 overlayers is correlated with the reduction in the lattice strain of the TiO2 nanoparticles.
i. The contractive lattice strain in the hydroxylated TiO2 nanoparticles is progressively decreased during the ALD Al2O3 deposition, resulting in the growth mode
transition.
7.2 Future Works
The study has clearly confirmed the fact that the energy level, surface coverage and growth mode of the core/shell electrodes play three important roles to enhance the efficiency of DSSCs. However, we may not complete the whole research of these topics. Some suggestions are listed below for future works
a. The interfacial energy levels at electrolyte/dye/shell/core interfaces should be further studied.
b. The mechanism of formation of dipole layers at electrolyte/dye/shell/core interfaces is important to investigate
c. Multi-shells and sintering model should be established for evaluating the coverage of electrolyte/dye/shell/core electrode.
d. The coverage model may apply to other devices, such as the electrode of Li-battery or quantum-dot solar cell.
e. Other kind of core/shell electrodes should be developed with the same analysis of the energy level, surface coverage and growth mode to enhance the efficiency of DSSCs.
f. The accuracy of the coverage and the energy levels measurements need to be confirmed. If the coverage in this study is confirmed to be less than 1, the energy levels should be modified accordingly.
References
1. Energy in Japan 2010, p13, published by Agency for Natural Resources and Energy, Japan.
2. 田大昌, 材料世界網, 7, 28, (2010).
3. M. Grätzel, Inorg. Chem., 44, 6841 (2005).
4. 田大昌, 材料世界網, 8, 27, (2008).
5. M. Grätzel, Nature, 414, 338 (2001).
6. A. Hagfeldt, G. Boschloo, L. Sun, L. Kloo, H. Petterson, Chem. Rev., 110, 6595 (2010).
7. 童永樑, 工業材料雜誌, 285, 156 (2010).
8. C. M. Elliote, Nature Chem., 3, 188 (2011).
9. DSSC Technology Trend and Market Forecast (2008~2015), Solar & Energy co. press, (2011).
10. B. O’Regan, M. Grätzel, Nature, 353, 737 (1991).
11. A. Zaban, S. G. Chen, S. Chappel, B. A. Gregg, Chem. Commun., 2231 (2000).
12. S. G. Chen, S. Chappel, Y. Diamant, A. Zaban, Chem. Mater., 13, 4629 (2001).
13. Z. S. Wang, C. H. Huang, Y. Y. Huang, Y. J. Hou, P. H. Xie, B. W. Zhang, H. M. Cheng, Chem. Mater., 13, 678 (2001).
14. E. Palomares, J. N. Clifford, S. A. Haque, T. Lutz, J. R. Durrant, Chem. Commun., 1464 (2002).
15. E. Palomares, J. N. Clifford, S. A. Haque, T. Lutz, J. R. Durrant, J. Am. Chem. Soc., 125, 475 (2002).
16. Z. S. Wang, M. Yanagida, K. Sayama, H. Sugihara, Chem. Mater., 18, 2912 (2006).
17. S. Wu, H. Han, Q. Tai, J. Zhang, S. Xu, C. Zhou, Y. Yang, H. Hu, B. Chen, B. Sebo, X. Z.
Zhao, Nanotechnology, 19, 215704 (2008).
18. R. H. Lee, Y. W. Huang, Thin Solid Films, 517, 5903 (2009).
19. C. Lin, F. Y. Tsai, M. H. Lee, C. H. Lee, T. C. Tien, L. P. Wang, S. Y. Tsai, J. Mater.
Chem., 19, 2999 (2009).
20. M. Shanmugam, M. F. Baroughi, D. Galipeau, Thin Solid Films, 518, 2678 (2010).
21. V. Ganapathy, B. Karunagaran, S. W. Rhee, J. Power Sources, 195, 5138 (2010).
22. M. Shanmugam, B. Bills, M. F. Baroughi, Mater. Res. Soc. Symp. Proc., 1260, 5 (2010).
23. J. T. Kim, S. H. Kim, Sol. Energy Mater. Sol. Cells, 95, 336 (2010).
24. G. R. R. A. Kummara, K. Tennakone, V. P. S. Perera, A. Konno, S. Kaneko, M. Okuya, J Phys. D, 34, 868 (2001).
25. A. Kay, M. Grätzel, Chem. Mater., 14, 2930 (2002).
26. N. G. Park, M.G. Kang, K. M. Kim, K. S. Ryu, S. H. Chang, Langmuir, 20, 4246 (2004).
27. Z. Liu, K. Pan, M. Liu, M. Wang, Q. Lu, J. Li, Y. Bai, T. Li, Electrochim. Acta, 50, 2583 (2005).
28. E. Ramasamy, J. Lee, J. Phys. Chem., 114, 22032 (2010).
29. H. J. Snaith, C. Ducati, Nano Lett., 10, 1259 (2010).
30. C. Prasittichai, J. T. Hupp, J. Phys. Chem. Lett., 1, 1611 (2010).
31. K. A. T. A. Perera, S. G. Anuradha, G. R. A. Kumara, M. L. Paranawitharana, R. M. G.
Rajapakse, H. M. N. Bandara, Electrochim. Acta, doi: 10.1016/j.electacta. 2011.01.110 (2011).
32. Y. J. Shin, K. S. Kim, N. G. Park, K. S. Ryu, S. H. Chang, Bull. Korean Chem. Soc., 26, 1929 (2005).
33. Y. J. Shin, J. S. Lee, J. H. Park, N. G. Park, Chem. Lett., 36, 1506 (2007).
34. Y. Y. Xi, Y. F. Hsu, A. B. Djurisic, W. K. Chan, J. Electrochem. Soc., 155, D595 (2008).
35. S. Ueno, S. Fujihara, Eur. J. Inorg. Chem., 2165 (2010).
36. K. Park, Q. Zhang, B. B. Garcia, X zhou, Y. H. Jeong, G. Cao, Adv. Mater., 22, 2329 (2010).
37. S. Ueno, S. Fujihara, Electrochim. Acta, 56, 2906 (2011).
38. H. Lia, Y. Liana, X. Wanga, W. Maa, L. Zhaob, Energy, 36, 1785 (2011).
39. http://rredc.nrel.gov/solar/spectra/am1.5 40. M. Grätzel, Acc. Chem. Res., 42, 1788 (2009).
41. V. Shrotriya, G. Li, Y. Yao, T. Moriarty, K. Emery, Y. Yang, Adv. Funct. Mater., 16, 2016 (2006).
42. H. Vogel, Photogr. Sci. Eng., 18, 35 (1874).
43. J. Moser, Monatsh. Chem., 8, 373 (1887).
44. H. Meier, J. Phys. Chem., 69, 719 (1965).
45. H. Tributsch, M. Calvin, Photochem. Photobiol., 17, 95 (1971).
46. H. Gerischer, Photochem. Photobiol., 16, 243 (1972).
47. C. W. Tang, Appl. Phys. Lett., 48, 183 (1986).
48. C. Y. Chen, M, Wang, J. Y. Li, N. Pootrakulchote, L. Alibabaei, C. H. Ngoc-le, J. D.
Decoppet, J. H. Tsai, C. Grätzel, C. G. Wu, S. M. Zakeeruddin and M. Grätzel, ACS Nano, 3, 3103 (2009).
49. M. Grätzel, Acc. Chem. Res., 42, 1790 (2009).
50. N. J. Cherepy, G. P. Smestad, M. Gratzel, J. Z. Zhang, J. Phys.Chem. B, 101, 9342 (1997).
51. Q. Dai, J. Rabani, New J. Chem., 26, 421 (2002).
52. I. Hod, M. Shalom, Z. Tachan, S. Ruhle, A. Zaban, J. Phys. Chem. C, 114, 10015 (2010).
53. T. C. Tien, F. M. Pan, L. P. Wang, C. H. Lee, Y. L. Tung, S. Y. Tsai, C. Lin, F. Y. Tsai, S.
J. Chen, Nanotechnology, 20, 305201 (2009).
54. Q. Zhang, G. Cao, Nano Today, 6, 91 (2011).
55. Y. Diamant, S. Chappel, S. G. Chen, A. Zaban, Coordin. Chem. Rev., 248, 1271 (2004).
56. A. Hagfeldt, M. Grätzel, Chem. Rev., 95, 49 (1995).
57. B. B. Ma, R. Gao, L. D. Wang, Y. F. Zhu, Y. T. Shi, Y. Geng, H. P. Dong, Y. Qiu, Sci.
61. D. Menzies, Q. Dai, Y. B. Cheng, G. P. Simon, L. Spiccia, Mater. Lett., 59, 1893, (2005).
62. S. J. Roh, R. S. Mane, S. K. Min, W. J. Lee, C. D. Lokhande,S. H. Han, Appl. Phys. Lett., 89, 253512 (2006)
63. S. Chappel, S. G. Chen, A. Zaban, Langmuir, 18, 3336 (2002).
64. S. Ito, N. L. C. Ha, G. Rothenberger, P. Liska, P. Comte, S. M. Zakeeruddin, P. Péchy, M.
K. Nazeeruddin, M. Grätzel, Chem. Commun., 4004 (2006).
65. S. A. Haque, E. Palomares, H. M. Upadhyaya, L. Otley, R. J. Potter, A. B. Holmes, J. R.
Durrant, Chem. Commun., 3008 (2003).
66. K. M. P. Bandaranayake, S. M. K. Indika, W. P. Prasad, K. Tennakone, Coord. Chem.
Rev., 248, 1277 (2004).
67. M. Scharrer, X. Wu, A. Yamilov, H. Cao, R. P. H. Chang, Appl. Phys. Lett., 86 151113 (2005).
68. M. D. Groner, F. H. Fabreguette, J. W. Elam, S. M. George, Chem. Mater., 16, 639 (2004).
69. M. Ritala, M. Leskelä, Nanotechnology, 10, 19 (1999).
70. L. Niinistö, J. Päiväsaari, J. Niinistö, M. Putkonen, M. Nieminen, Phys. Stat. Sol. (a), 201, 1443 (2004).
71. C. A. Wilson, R. K. Grubbs, S. M. George, Chem. Mater., 17, 5625 (2005).
72. S. Y. Huang, G. Schlichthorl, A. J. Nozik, M. Gra¨tzel,A. J. Frank, Phys. Chem. B, 101, 2576 (1997).
73. G. Liu, W. Jaegermann, J. He, V. Sundstrom, L. Sun, J. Phys. Chem. B, 106, 5814 (2002).
74. J. H. Snook, L. A. Samuelson, J. Kumar, Y. G. Kim, J. E. Whitten, Organic Electron., 6, 55 (2005).
75. F. D. Angelis, S. Fantacci, A. Selloni, Nanotechnology, 19, 424002 (2008).
76. H. Ishii, K. Sugiyama, E. Ito, K. Seki, Adv. Mater., 8, 605 (1999).
77. W. Song, M. Yoshitake, Appl. Surf. Sci., 251, 14 (2005).
78. H. Lindstrom, H. Rensmo, S. Sodergren, A. Solbrand, S. E. Lindquist, J. Phys. Chem. B, 100, 3084 (1996).
79. M. K. Nazeeruddine, A. Kay, I. Rodicio, R. Humphry-Baker, E. Muller, P. Liska, N.
Vlachopoulos, M. Grätzel, J. Am. Chem. Soc., 115, 6382 (1993).
80. T. C. Tien, F. M. Pan, L. P. Wang, F. Y. Tsai, C. Lin, J. Phys. Chem. C, 114, 10048 (2010).
81. R. L. Puurunen, Chem. Vap. Deposition, 9, 327 (2003).
82. R. L. Puurunen, W. Vandervorst, J. Appl. Phys., 96, 7686 (2004).
83. G. Liu, W. Jaegermann, J. He, V. Sundstrom, L. Sun, J. Phys. Chem. B, 106, 5814 (2002).
84. J. F. Moulder, W. F. Stickle, P. E. Sobol, K. D. Bomben, Handbook of X-ray Photoelectron Spectroscopy, Perkin–Elmer Press: Eden Prairie, MN, 45–73 (1962).
85. A. J. Gonzalez, D. Schmeisser, Surf. Sci., 250, 59 (1991).
86. W. Song, M. Yoshitake, Surf. Interf. Anal, 38, 793 (2006).
87. T. Toyoda, I. Tsuboya, Rev. Sci. Instrum., 74, 782 (2003).
88. D. D. Claudio, A. R. Phani, S. Santucci, Optical Materials, 30, 279 (2007).
89. P. J. Potts, A Handbook of Silicate Rock Analysis, Chapman & Hall press, p.336 (1987).
90. B. Ealet, M. H. Elyakhloufi, E. Gillet, M. Ricci, Thin Solid. Film, 250, 92 (1994).
91. I. Costina, R. Franchy, Appl. Phys. Lett., 78, 4139 (2001).
92. M. Brause, S. Skordas, V. Kempter, Surf. Sci., 445, 224 (2000).
93. F. D. Angelis, S. Fantacci, A. Selloni, Nanotechnology, 19, 424002 (2008).
94. S. M. Sze, Physics of Semiconductor Devices, John Wiley & Son press, p97 (1983).
95. D. A. Neamen, Semiconductor Physics and Devices, McGraw-Hill press p349~p358 (2003).
96. J. Zhang, A. Zaban, Electrochimica Acta., 53, 5670 (2008).
97. J. N. Gillet, M. Meunier, J. Phys. Chem. B, 109, 8733 (2005).
98. J. E. Martin, A. A. Herzing, W. Yan, X. Q. Li, B. E. Kobel, C. J. Kiely, W. X. Zhang, Langmuir, 24, 4329 (2008).
99. O. Renault, R. Marlier, N. T. Barrrett, E. Martinez,T. Baron, M. Gely, B. De Salvo, Surf.
Interface Anal., 38, 486 (2006).
100. M. Mohai, I. Bertoti, Surf. Interface Anal., 36, 805 (2004).
101. Z. Sitar, L. L. Smith, R. F. Davis, J. Crystal Growth, 141, 11 (1994).
102. S. Tanuma, C. J. Powell, D. R. Penn, Surf. Interface Anal., 11, 577 (1988).
103. E. E. Underwood, Quantitative Stereology, Addison-Wesley publication: Massachusetts, 178 (1962).
104. L. G. Gosset, J. F. Damlencourt, O. Renault, D. Rouchon, P. Holliger, A. Ermolieff, I.
Trimaille, J. J. Ganem, F. Martin, M. N. Semeria, J. Non-Cryst. Solids, 303, 17 (2002).
105. P. P. Ahonen, E. I. Kauppinen, J. Mater. Res., 14, 3938 (1999).
106. J. C. Parker, R. W. Siegen, J. Mater. Res., 5, 1246 (1990).
107. E. H. Poniatowski, R. R. Talavera, M. C. Heredia, O. C. Corona, R. A. Murillo, J. Mater.
Res., 9, 2102 (1994).
108. G. Li, L. Li, J. Boerio-Goates, F. Woodfield, J. Am. Chem. Soc., 127, 8659 (2005).
Vita
基本資料 姓名：田大昌 性別：男
出生年月：民國 57 年 10 月 電子信箱：[email protected]
學歷
國立交通大學材料科學與工程學研究所博士班(2004.9~2011.6) 國立台灣大學材料科學與工程學研究所碩士班(1992.9~1994.6) 國立台灣大學地質學系(1988.9~1992.6)
經歷
工研院材料所副研究員(1994~1999) 工研院材料所研究員(1999~至今)
工研院奈米中心兼任技術經理(2007~2011)
美國化學學會 Langmuir、ACS Appl. Mater. Interfaces 期刊評論員 (2009~至今)
專長：介面能階分析、核/殼材料覆蓋率分析、薄膜化態分析等。
著作
國際期刊論文
1. T. C. Tien, F. M. Pan, L. P. Wang, F. Y. Tsai, C. Lin, Coverage analysis for
10048 (2010).
2. T. C. Tien, L. C. Lin, L. S. Lee, C. J. Hwang, S. Maikap, Y. Shulga, Analysis of weakly bonded oxygen in HfO2/SiO2/Si stacks by using HRBS and ARXPS, J. Mater. Sci.: Mater. Electron., 21, 475 (2010).
3. A. Das, S. Maikap, C. H. Lin, P. J. Tzeng, T. C. Tien, T. Y. Wang, L. B.
Chang, J. R. Yang, M. J. Tsai, Ruthenium oxide metal nanocrystal capacitors with high-k dielectric tunneling barriers for nanoscale nonvolatile memory device applications, Microelectronic Engineering, 87, 1821 (2010).
4. T. C. Tien, F. M. Pan, L. P. Wang, C. H. Lee, Y. L. Tung, S. Y. Tsai, C. Lin, F. Y. Tsai, S. J. Chen, Interfacial energy levels and related properties of atomic-layer-deposited Al2O3 films on nanoporous TiO2 electrodes of dye-sensitized solar cells, Nanotechnology, 20, 305201 (2009).
5. C. P. Chen, T. C. Tien, B. T. Ko, Y. D. Chen, C. Ting, Energy level alignment at the anode of poly(3-hexylthiophene)/fullerene-based solar cells,
ACS Appl. Mater. Interfaces, 1(4). 741 (2009).
6. T. M. Chen, J. Y. Hung, F. M. Pan, L. Chang, S. C. Wu, T. C. Tien, Pulse electrodeposition of iridium oxide on silicon nanotips for field emission study, J. Nanosci. Nanotech., 9(5), 3264 (2009).
7. C. Lin, F. Y. Tsai, M. H. Lee, C. H. Lee, T. C. Tien, L. P. Wang, S. Y. Tsai, Enhanced performance of dye-sensitized solar cells by an Al2O3 charge-recombination barrier formed by low-temperature atomic layer deposition, J. Mater. Chem., 19, 2999 (2009).
8. S. Maikap, A. Das, T. Y. Wang, T. C. Tien, L. B. Chang, High-k HfO2 Nanocrystal Memory Capacitors Prepared by Phase Separation of Atomic-Layer-Deposited HfO2/Al2O3 Nanomixtures, J. Electrochem. Soc.,
156, 3, K28 (2009).
9. S. Maikap, S. Z. Rahaman, T. C. Tien, Nanoscale nonvolatile memory
characteristics using n-Si/SiO2/HfAlO nanocrystal/Al2O3/Pt capacitors,
Nanotechnology, 19, 435202 (2008).
10. Y. M. Shulga, T. C. Tien, C. C. Huang, S. C. Lo, V. E. Muradyan, N. F.
Polyakova, Y. C. Ling, R. O.Loutfy, A. P. Moravsky, XPS study of fluorinated carbon multi-walled nanotubes, J. Electron Spectroscopy, 160, 22 (2007).
11. S. Maikap, T. Y. Wang, P. J. Tzeng, T. C. Tien, L. S. Lee, J. R. Yang, M. J.
Tsai, Band offsets and charge storage characteristics of atomic layer deposited high-k HfO2/TiO2 multilayers, Appl. Phys. Lett., 90, 262901 (2007).
12. S. Maikap, P. J. Tzeng, H. Y. Lee, C. C. Wang, T. C. Tien, L. S. Lee, M. J.
Tsai, Physical and electrical characteristics of atomic layer deposited TiN nanocrystal memory capacitors, Appl. Phys. Lett., 91, 043114 (2007).
13. W. H. Tuan, T. C. Tien, Effect of addition of a small amount of silver on the microstructure and mechanical properties of YBa2Cu2O7−x, Mater. Chem.
Phys, 39, 72 (1994).
14. W. H. Tuan, T. C. Tien, Mechanical performance of YBa2Cu3O7−x-Ag composites, J. Mater. Sci. Lett., 13, 1019 (1994).
研討會論文
1. Ta-Chang Tien, Yu-Ming Wang, Jun-Chin Liu, C. S. Chou, New development in nanotechnology for solar cells, International nanotechnology exhibition and conference (Nano Tech 2010).
2. Ta-Chang Tien, Fu-Ming Pan, Lih-Ping Wang, Song-Yeu Tsai, Ching Lin,
Feng-Yu Tsai, 染料敏化太陽電池之殼/核電極之覆蓋率模型, 奈米元件 技術研討會 (SNDT 2010).
3. Lih-Ping Wang, Ta-Chang Tien, Fu-Ming Pan, Song-Yeu Tsai, Ching Lin, Feng-Yu Tsai, 氧化鋁於染料敏化太陽能電池 ALD 成長分析, 奈米元件
3. Lih-Ping Wang, Ta-Chang Tien, Fu-Ming Pan, Song-Yeu Tsai, Ching Lin, Feng-Yu Tsai, 氧化鋁於染料敏化太陽能電池 ALD 成長分析, 奈米元件