植入量子點對硫硒化銅銦薄膜太陽能電池性能改善的研究

Abstract

本論文研究利用貼靶濺鍍法將PbS、GaSb及InSb等摻入CuIn(SeS)2（CISS）薄膜中，並以施予快速退火（Rapid Thermal Annealing，RTA）處理，製備含有量子點的CIS薄膜，探討量子點材料種類、濃度與RTA及硒化（Selenization）退火處理時間對CIS薄膜性質之影響。X光繞射分析發現，控制RTA時間及摻雜濃度可以避免量子點成長而析出二次相，電子顯微鏡（Transmission Electron Microscopy，TEM）分析顯示，RTA處理使CISS量子點薄膜結晶從5 nm上升至30 nm並成功地將4至6 nm量子點鑲入CISS薄膜；硒化後退火處理使CISS量子點薄膜結晶從5 nm上升至1 μm，但TEM顯示薄膜中已無量子點結構，且CISSe薄膜會轉變成CuIn(Se)2（CIS）薄膜；摻入GaSb之CISS薄膜經硒化後退火處理能改善其結晶特性，薄膜缺陷之降低改善了載子遷移率，使電池元件之光電轉換效率上升。

The CuIn(SeS)2 (CISS) thin films doped with PbS, GaSb and InSb quantum dots (QDs) were prepared by using the target-attachment sputtering method in conjunction with the rapid thermal annealing (RTA) process. X-ray diffraction analysis indicated the control of dopant amount and annealing time is essential to avoid the coalescence of QDs and the reactions with CISSe matrix to form the second phases. Transmission electron microscopy revealed that the grain size of CISS increases from 5 to 30 nm and the QDs with the sizes in 4 to 6 nm form in CISS thin films subjected to the RTA process. Selenization treatment enlarged the grain size of CISS from 5 nm to 1 μm; nevertheless, it caused the transformation CISS film to CuIn(Se)2 (CIS) film and eliminated the presence of QDs in the CISe film. Improvement of crystallinity was observed in CISS film incorporated with GaSb, The reduction of crystalline defect improved the carrier mobility in CISS and consequently increase the conversion efficiency of solar cell samples containing such a doped CISS absorber layer.