Title :
Improved efficiency of Cu(In,Ga)Se2 thin film solar cells with chemically deposited ZnS buffer layers by air-annealing-formation of homojunction by solid phase diffusion
Author :
Nakada, Tokio ; Mizutani, Masayuki
Author_Institution :
Dept. of Electr. Eng. & Electron., Aoyama Gakuin Univ., Tokyo, Japan
Abstract :
The authors found that a role of the annealing process in CBD-ZnS/CIGS solar cells is the diffusion of Zn and S into CIGS thin films even at relatively low temperature of 200°C. A new technique to form a homojunction of CIGS thin film solar cells by Zn-diffusion from ZnS layer is proposed, 17.7 % efficiency Cd-free CIGS solar cell has been fabricated by optimizing the annealing process, thickness of buffer layers, and CIGS absorber layers. This result suggests that high efficiency CIGS thin film solar cells can be achieved even if Cd is not utilized
Keywords :
II-VI semiconductors; annealing; copper compounds; gallium compounds; indium compounds; p-n junctions; semiconductor device measurement; semiconductor device testing; semiconductor growth; semiconductor thin films; solar cells; zinc compounds; 17.7 percent; 200 C; ZnS-Cu(In Ga)Se2; ZnS-Cu(In,Ga)Se2 thin film solar cells; absorber layer thickness optimisation; annealing process; buffer layer thickness optimisation; chemical bath diffusion; homojunction formation; photovoltaic efficiency improvement; Annealing; Bonding; Buffer layers; Chemicals; Computational Intelligence Society; Photovoltaic cells; Sputtering; Transistors; Zinc compounds; Zinc oxide;
Conference_Titel :
Photovoltaic Specialists Conference, 2000. Conference Record of the Twenty-Eighth IEEE
Conference_Location :
Anchorage, AK
Print_ISBN :
0-7803-5772-8
DOI :
10.1109/PVSC.2000.915889
