利用電鍍銅銦金屬層及後硒化方式製備銅銦硒太陽電池吸收層

Preparation of CuInSe2 Absorber Layers by Selenization of Electrodeposited Cu-In Metal Films for Solar Cell

郭豐綱(Fong-Gang Guo)

指導教授 ： 李志浩 ； 邱秋燕

國立清華大學/原子科學院/工程與系統科學系/碩士(2010年)

https://doi.org/10.6843/NTHU.2010.00104

摘要

本實驗以電鍍Cu-In金屬層配合後硒化方式成功製備CuInSe2吸收層，並在0.12 cm2量測到9.3%的最高效率。電鍍Cu-In金屬之前以濺鍍法沉積一層Mo金屬於玻璃上，發現當Mo厚度大於100 nm時其片電阻及可見光反射率已趨向於定值但在此製程參數下仍有應力過大(5~7 GPa)及易剝落的問題，固參考NREL等文獻後希望利用雙層的結構並將厚度控制在0.5μm以下。完成電鍍Cu-In金屬後將之與硒碇一起放入管爐內進行硒化反應發現In較Cu先與Se反應產生二元硒化物並在約300~350℃時產生分層的現象即CuSex聚集在表面而InSex則傾向聚集在Mo背電極，隨著溫度升高至450~500℃此分層現象消失最後形成一均勻的CuInSe2薄膜。在Cu-In金屬硒化過程當中Mo背電極通常也參與反應生成MoSe2，少量(100~200 nm)有助於增加與CuInSe2的附著性但若Mo與過量Se反應而完全生成MoSe2或剩餘少量的Mo則增加電池的串聯電阻，因此我們提出利用控制Se分壓的兩階段硒化法來達到Cu-In金屬被硒化生成CuInSe2而Mo 背電極只少量被硒化使得MoSe2的厚度小於500 nm。

關鍵字

銅銦硒 ； 電鍍

並列摘要

CuInSe2 absorber layer prepared by electrodeposited Cu-In metal precursor followed by selenization has been successfully fabricated and the device with 9.3% efficiency on 0.12 cm2 were demonstrated. First, single layer Mo films with different thickness are sputtered on glass and found the sheet resistance and reflectance of visible light approach to a constant value when thickness greater than 100 nm. Sputtered Mo films were under tensile stress (5~7 GPa) and easy exfoliation, thus we conclude a better Mo structure with bilayer and 0.5μm thickness followed the NREL and others results.
After electrodepositing Cu-In metal films, the samples were put into tube furnace with Se pieces for selenization. By XAS analysis that In is easilier to react with Se than that of Cu to form binary selenides. During the selenization at 300~350℃ films tend to form bilayer structure with CuSex on top and InSex near the Mo back contact. The film transformed to CuInSe2 uniformly after selenization at 450~500℃.
The other issue is MoSe2 formation during selenization, it improves the adhesion at CIS/Mo interface if a moderate thickness (100~200 nm) was formed but it also increases the series resistance of solar cell for a thick MoSe2 (almost Mo were selenized ). We propose a two steps selenization process for supplying overdose Se at first then reducing Se at final step to control MoSe2 thickness below 500 nm without affecting CuInSe2 grain growth.

並列關鍵字

CuInSe2 ； CIGS

參考文獻

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