Title :
Photovoltaic properties of Cu(In,Ga)Se2 thin film solar cell fabricated by coevaporation process
Author :
Nishitani, M. ; Negami, T. ; Ikeda, M. ; Kohara, N. ; Terauchi, M. ; Wada, T. ; Hirao, T.
Author_Institution :
Central Res. Labs., Matsushita Electr. Ind. Co. Ltd., Soraku, Japan
Abstract :
Thin film solar cells based on Cu(In,Ga)Se2 films were fabricated, and their junction and photovoltaic properties were investigated. Ga in CuInSe2 thin films formed by the so-called “bilayer process” was incorporated homogeneously. The fabricated cell structure was glass/Mo/Cu(In,Ga)Se2/CdS/ZnO/ITO(/MgF2). The incorporation of Ga into CuInSe2 films up to about 20 mol% improved the photovoltaic performance. From the study of photoluminescence, capacitance-voltage and current-voltage characteristics, it was clarified that the incorporation of Ga not only widened the bandgap energy, but also played an important role in the effect which yields hole concentration. The best cell with an AR-coating (MgF2) exhibited an efficiency of 15.2%; Jsc=33.9 mA/cm2 , Voc=0.616 V, FF=0.730. The device performance can be improved by the development of the film with higher hole concentration, keeping the crystalline quality
Keywords :
copper compounds; energy gap; gallium compounds; indium compounds; p-n heterojunctions; semiconductor device testing; semiconductor growth; semiconductor thin films; solar cells; vapour deposited coatings; vapour deposition; 0.616 V; 15.2 percent; C-V characteristics; Cu(In,Ga)Se2 solar cells; CuInGaSe2; I-V characteristics; bandgap energy; bilayer process; coevaporation process; fabrication; fill factor; hole concentration; junction properties; open-circuit voltage; photoluminescence; photovoltaic properties; short-circuit current; thin film semiconductor; Capacitance-voltage characteristics; Current-voltage characteristics; Glass; Indium tin oxide; Photoluminescence; Photovoltaic cells; Photovoltaic systems; Solar power generation; Transistors; Zinc oxide;
Conference_Titel :
Photovoltaic Energy Conversion, 1994., Conference Record of the Twenty Fourth. IEEE Photovoltaic Specialists Conference - 1994, 1994 IEEE First World Conference on
Conference_Location :
Waikoloa, HI
Print_ISBN :
0-7803-1460-3
DOI :
10.1109/WCPEC.1994.519848
