銅銦鎵硒薄膜太陽能電池技術與應用趨勢

(1)

銅銦鎵硒薄膜太陽能電池技術與應用趨勢

工研院材料與化工研究所

廖曰淳

(2)

1905年

愛因斯坦

提出光量子的觀念，而且精采地解釋了

光電效應

的原理。

(1921年

愛因斯坦因光電效應原理的發現，而獲頒諾貝爾物理獎

)

1887年 Hertz在研究火花放電的實驗時，

發現用紫外光照射純鋅電極由電極間會產生頻繁的火花放電。

1954年 Bell實驗室發明第一個太陽能電池，當時效率只有6%

1957~1969年美蘇太空競賽-太陽電池於太空應用。

太陽能電池發展史

1970年能源危機-太陽光發電系統地面應用(Si) 。

1980年消費性薄膜太陽電池應用(a-Si, CdS/CdTe)。

1990年與公用電力併聯之太陽光發電系統技術成熟

(Grid-Connected PV System, Si)

1992年起歐、美、日各國推動太陽光發電系統補助政策。

2000年建材一體型太陽電池應用(BIPV)。

(3)

J (mA/cm2₎ V( v ) Voc Jsc Maximum { J x V } Voc Jsc

Fill Factor (FF)= Maximum { J x V }

Voc x Jsc

Power efficiency η(%) =

FF x Voc x Jsc

Sun light power

太陽能電池基礎原理

(4)

太陽能電池材料及種類

理想的太陽能電池材料特性：

1. Bandgap between 1.1eV and 1.7eV.

2. Direct bandgap material 3. Non-toxic materials 4. Large area production

5. High photovoltaic conversion efficiency 6. Long term stability.

Crystalline Si solar cell (1st Gen.)

DSSC polymer

Organic solar cell (3rd Gen.)

http://www.e-tonsolar.com/edu.htm ¾ Crystalline Si

¾ MutliCrystaline Si

Thin film solar cell (2nd Gen.) ¾ Amorphous Si

¾ CdTe

¾ CIS/CIGS ¾ III-V

(5)

Earth

AM0 AM1 AM1.5 大氣層 45o

AM 即 Air Mass，(不同 Air Mass 代表不同太陽光光譜)

• AM0 (Air Mass 0) ~ 1,400 W •m

-2

• AM1 (Air Mass 1) ~ 1,000 W •m

-2

• AM1.5 (Air Mass 1.5) ~ 844 W•m

-2

AM1.5 1,000 W

•m

-2 _{(IEC 891、 IEC 904-1)}

效率量測

(6)

太陽能電池效率演進

(7)

薄膜太陽能電池最佳效率比較

(8)

薄膜太陽能電池之優勢

z Mass product

¾ High throughput

¾ Large area production

z Low cost

¾ cheap substrate

¾ Low thermal budget

¾ Low material cost

z Wild application

¾ flexible

CIGS solar cell

CIGS solar cell _CdTe_CdTe _{solar cell}_{solar cell} _a_a_-_-_Si_Si

Best cell and module efficiency

(19.88%, 13%)

Good cell and module efficiency

(16.5%, 11%)

Worst cell and module efficiency

(9)

太陽能電池市場現況

Prometheus Institute(2006/8) Solarbuzz; ITRI-IEK (2007/3) 各類太陽能電池市佔比各類太陽能電池市佔比 2001~20052001~2005年各類太陽能電池產量年各類太陽能電池產量

(10)

太陽能電池市場預測

(11)

薄膜太陽能電池量產預測

(12)

CIGS

薄膜太陽能電池量產預測

2005年：

¾CIGS 產量為5MW

¾CIGS之PV 市佔<1%

¾ CIGS之薄膜市佔4.6%

(13)

此類型有兩種：一種含銅銦硒三元素（簡稱CISe），一種含銅銦鎵硒四元素（簡稱CIGS）。由於其高光電效率及低材料成本，被許多人看好。在實驗室完成的CIGS光電池，光電效率最高可達約19.88，就模組而言，最高亦可達約13﹪(CISe 約10%)。CIGS隨著銦鎵含量的不同，其光吸收範圍可從1.02ev至1.68ev，此項特徵可加以利用於多層堆疊模組，已近一步提升電池組織效能。此外由於高吸光效率（α>104_~105_㎝-1_），所需光電材料厚度不需超過1μm，99﹪以上的光子均可被吸收，因此一般粗估量產製造時，所需半導體原物料可能僅只US$0.03/W。

薄膜太陽能電池

–

_–

CIGS

薄膜電池

I III VI

₂

Chalcopyrite

(14)

Chalcopyrite

半導體的性質

*CIGS (E_g=1.04eV-1.68eV);

E_g(x)=(1-x) E_g(CIS) +x E_g(CGS)-bx(1-x); x : Ga ratio b : 0.15~0.24

(15)

CIGS

(16)

sputtering

Chemical Bath deposition

zVacuum method ¾Co-evaporation ¾Sputtering + selenization zNon-Vacuum method ¾ Electro-deposition + selenization ¾ Printing+ selenization sputtering

CIGS

太陽能電池元件製作流程

(17)

三道真空製程與三道Patterning製程，設備投資成本高

製程不均勻性造成模組下降，大面積化不易

CIGS

(18)

CIGS

(19)

(a,b) IPE ; (d,c) ZSW; (e) Wurth Solar 公司採用之技術 ZSW 模組效率分佈圖 (ZSW)

真空塗佈製程

-

_-

Co

-

evaporation

(20)

真空塗佈製程

-

_-

Co

-

evaporation

In the second stage, Cu and Se were codeposited while the substrate temperature was ramped up to 580 ℃.

In the first stage, In, Ga and Se were coevaporated at 400 ℃ substrate temperature with a reduction in the Ga flux after the first half.

After reaching a Cu excess of approximately 10%, In, Ga and Se

were coevaporated still at 580 ℃ in order to obtain an (In,Ga)-rich composition. The samples were then cooled in Se

atmosphere down to 250 ℃

(21)

真空塗佈製程

-

_-

Sputtering

ＮＥＤＯパンフレットより鹼緩衝雷射圖案1 (雷射法) 高阻抗ZnO系緩衝層加工 DC磁控管濺鍍法 DC磁控管濺鍍法圖案2 (機構法) 堆疊完成封裝沿用結晶矽太陽電池模組技術圖案3(機構法) 玻璃

(22)

真空塗佈製程

-

_-

Sputtering

本田在2006年12月成立了生產和銷售子公司「Honda Soltec」正式立足太陽能產

業。Honda Soltec從2007年3月開始銷售本田工程（Honda Engineering）生產的CIGS

太陽能電池。並且在2007年第三季，在熊本製作所內建設的工廠正式量產，針對全日本

市場展開銷售。熊本工廠的量產規模預定為年產27.5MW。

熊本製作所

http://www.honda.co.jp/soltec/energy/index.html

(23)

A novel low-cost Cu(In,Ga)Se2 (called CIGS) solar cell process was developed. The cost savings compared to traditional CIGS processes are due to fast processing times and the use of simple non-vacuum equipment. Therefore initial investment for a production line is reduced to a minimum and allows even small companies to enter the solar cell production business.

1. Preaparation of nano-sized precursor paste

2. Fast printing of 2µm thin precursor film 3. Chemical conversion by thermal annealing 4. Cell processing http://www.tfp.ethz.ch/lowcost/lowcost.html

CIGS

太陽能電池

-

非真空製程

(24)

CIGS

(25)

非真空塗佈製程

-

_-

electrodeposition

(26)

非真空塗佈製程

-

_-

Metal Oxide

Ink

Crack & In2O3 impurity contains No efficiency 13.6% (0.08cm2 Mo-glass)/11.7% (Mo-foil)/8.9 (Upilix)/8 (mini-module 65cm2₎ 11.7% Efficiency N.A. Cross-section Se source: 300-450o_C Substrate: 500-550o_C 10-30min H2/N2: 500-550oC H2Se/N2:475-550o_C H2, H2Se 400-600o_C Grain Growth Process Doctor-Blade Doctor-Blade Doctor-Blade/Spray Precursor Dep. Method CI Metal Oxide Nanoparticles (~100nm) CIG Metal Oxide Nanoparticles

Metal Oxide(Cu, In, Ga) Nanoparticles

Ink type

ETHZ (1) ISET

(27)

Unisun

(28)

NREL (2)

[Cu(CH3CN)4](BF4] +2.5 Na2Se ÆCuSe 2InI3+3Na2SeÆ In2Se3

N.A. Se source: 350o_C Substrate: 550o_C 30min, 20sccm Spray deposition CIGS nanoparticles

Korea Institute of Energy Research Crack & Without densification Se source: 300-450o_C Substrate: 500-550o_C 10-30min Doctor-Blade Cu0.9InSex In-rich nanoparticles ETHZ Liquid-assisted growth was not observed. Anneal 600oC/20min Spray deposition [Cu(CH3CN)4](BF4)2+ InI3+2.5 Na2Se Æ CuInSe2.5(amorphous colloid) (in pyridine/methaol)

NREL (1)

Liquid-assisted growth was not observed. (larger frain on surface)

Anneal 600oC/20min Spray deposition CuSe/In2Se3/Mo Efficiency Cross-section Grain Growth Process Precursor Dep. Method Ink type

非真空塗佈製程

(29)

Korea Institute of Energy Research

Cu powder In powder Ga powder Se powder Ethylenediamine In Teflon autoclave

Sealed and heated at 140~280℃ for 36hr Cooling to room temperature Filter (30~80nm) and washing (H₂O/C₂H₅OH) Vacuum-dried at 80℃ for 6hr

(30)

1.11% (Voc=332mV, Jsc=10.881mA/cm2_, FF=0.31) RTP 500-600o_C 5 min Electrospray In-Se/Cu-Se Core-shell structure Æ cover with Se nanoparticles LG Chem, Ltd 2.71% (Voc=325mV, Jsc=28.3 mA/cm2_, FF=0.295) Heat treatment at 575oC under N2 Screen Printing

Cu, In, Ga, Se powders Æ Ball mill for CIGS fine powder Æ Ink prepare

Wada et.al. 14.5% (Voc=599mV, Jsc=32.2mA/cm2_, FF=0.723 for 0.47cm2₎ RTP Roll Printing 1st: Cu-Se Ink 2nd_{: Selenide ink} Nanosolar Efficiency Cross-section Grain Growth Process Precursor Dep. Method Ink type ~7μm

非真空塗佈製程

(31)

Champion cell of non

-

vac

. method

SEM images of CIGS film on glass (left) and on foil (right).

Low-angle (3°) grazing incidence x-ray diffraction spectra for CIGS films on glass and on foil.

SEM image of CIS film grown from (non-oxide, non-metallic) NPs

NREL measured one of Nanosolar’s cells on glass at about 14% on a total-area basis, equivalent to about 14.5% on an active-area basis after correcting for shadowing by the grid (Voc = 599mV, Jsc = 32.2mA/cm2_{,FF =}

(32)

Nanosolar將設全美最大太陽能電池製造廠 95-06-22 中央社記者吳日君舊金山二十一日專電矽谷太陽能研發新創公司Nanosolar今天宣布，將在舊金山灣區建立全美最大的太陽能電池製造工廠，期望能生產每年四億三千萬瓦產能、約有兩億個太陽能電池，足夠供應三十二萬五千戶家庭電力。廠房完成後，將使加州成為美國太陽能使用的先鋒。Nanosolar執行長洛斯許森指出，選擇在高科技重鎮矽谷設廠，而非在工資低廉的國家或其他發展中國家，主因為更靠近公司總部研發中心，此外，由於大部分製造過程皆為自動化，人力成本在廠房管理支出，所佔比例並不高。 Nanosolar總部設在矽谷，在德國也設有辦公室。首間太陽能面板工廠將設在德國柏林，每年將可生產超過一百萬個太陽能面板。公司種子基金來自Google兩位共同創辦人布林與佩吉。二零零二年開始，公司研發團隊目標，朝向研發製造大量太陽能電力，使其不再是遙不可及的高價產品。在四年的研發過程後，Nanosolar發展出更便宜、可大量製造的太陽能電池。 Nanosolar科技長艾柏斯佩許表示，薄模設計可減少吸收光源材料的需求，解決太陽能發電的複雜性、高成本問題，可更有效大量生產太陽能設備。根據統計，去年全球太陽能產業總額為一百一十二億美元，預估二零一五年可達五百一十億美元。目前日本與歐洲都有太陽能製造廠，美國排名第三，佔全球市場百分之十。若這座位在舊金山灣區的太陽能廠完工，將成為日本之後、全球第二大太陽能廠。

(33)

~4% N.A. Thermal treatment <400o_C Spin-coating (N2H4)x(N2H5)3(In2 Cu2Se4S3) IBM 6.7% (Voc=404mV, Jsc=27.2mA/cm2_, FF=0.61 for 0.47cm2₎ Se source: 350o_C Substrate: 560o_C 10min/10mbar N2 Doctor-Blade

Cu(NO3)2, Ga(NO3)3, InCl3 in CH3OH Æ Ethylcellulose/1-Pantaol配成sol-gel paste

ETHZ (2)

(Metal Nitrate & Metal Chloride) ~1% Efficiency Cross-section Se source: 300-450o_C Substrate: 500-550o_C 10-30min Grain Growth Process Doctor-Blade Precursor Dep. Method Cu, In nanopowders (~100nm some 1μm) Ink type ETHZ (1) ~0.5μm

非真空塗佈製程

-

_-

Others

(34)

IBM

Cu2S/S =1:2 In2Se3/Se =1:1

Dissolved in distilled hydrazine

Mixing (N2H4)x(N2H5)3(In2Cu2Se4S3) x~0.7 N2H4 N2H5+ (In2Cu2Se4S3) 6-Dilute 8 times or 15mg/mL by distilled hydrazine

In N₂ filled Glove Box or Dry Box

0.2μm pore filter Spin-coat 3500rpm 1min Drying 100o_{C 5min} (NH2NH2 bp.=113.5 °C) CuInSe2 formation 350o_C _20min

Formation of polychalcogenide anion

(N2H4)x(N2H5)3(In2Cu2Se4S3) x~0.7

(35)

¾ 各類型太陽能電池的市場需求將與日遽增，且各技術皆以

降低成本和提高光電轉換效率為研究方向。其中又以薄膜太陽

能電池為現階段最具有取代矽晶太陽能電池的可能。

¾ 薄膜太陽電池中，CIGS是目前具有最高效率的電池之一。

¾ 現階段CIGS電池主要量產技術仍以真空製程技術為主，但

難以克服大面積及降低成本的問題。

¾ CIGS非真空製程技術雖具有降低成本以及提高材料使用率

的優點，但各方式都具有難以克服的關鍵問題皆仍待解決。如

CIGS晶粒成長…等。

結論

(36)

CIGS電池技術瓶頸

CIGS薄膜太陽能電池雖具有高效率、低成本、大面積與可撓性等潛力優

勢，但還有許多需要克服的問題接踵而來：

¾ 製程複雜、技術選擇百家爭鳴，且供應練相當分歧，各站並無制式化設備 ¾ 放大製程之均質性不佳，良率變化大 • dopant ratio

• thin window layer

• Low Voc resulting in increased area loss

¾ 系統化的研究與實驗數據十分缺乏 •許多關鍵點都無定論，如：組成成分、結構、晶界、各層間之介面…等 ¾ 關鍵原料的缺乏 • 銦元素也是一項潛在隱憂，銦的天然蘊藏量相當有限，國外曾計算，如以效率10﹪的電池計算，人類如全面使用CIGS光電池發電供應能源，可能只有數年光景可用。

(37)

CIGS

(38)

 CIGS Flexible Module

 Power Integration  Energy Storage

Alternatives

 Fastening Methods

 Orientation & Prediction

Model Verification

CIGS

(39)

CIGS

(40)

CIGS

(41)

“LIGHTWEIGHT PORTABLE POWER BY GLOBAL SOLAR”

CIGS

(42)

銅銦鎵硒薄膜太陽能電池技術與應用趨勢