Title :
Improvement for high-efficiency, stable multi-junction cells
Author :
Maruyama, E. ; Terakawa, A. ; Sayama, K. ; Ninomiya, K. ; Hishikawa, Y. ; Tarui, H. ; Tsuda, S. ; Nakano, S. ; Kuwano, Y.
Author_Institution :
Functional Mater. Res. Center, Sanyo Electr. Co. Ltd., Osaka, Japan
Abstract :
The world´s highest conversion efficiency of 12.0% was obtained for a 100 cm2 single-junction a-Si solar cell submodule, by combining a high-quality i-layer, a high-quality buffer layer treated by hydrogen plasma, and other successful techniques. For further improvement in the conversion efficiency and long-term stability, high-quality a-SiGe:H was studied for use on the bottom cell of the multijunction solar cell. The authors´ research, focusing on film composition, revealed that the optical gap (Eopt3) of a-SiGe:H could be expressed by Eopt3=1.3CH- 0.6C Ge+1.4(eV), where CH is H content and CGe is Ge content. Moreover, film qualities were found to be dependent on CH and CGe even at the same Eopt3. These results led to high-efficiency and stable a-Si/a-Si/a-SiGe multijunction solar cells
Keywords :
Ge-Si alloys; elemental semiconductors; energy gap; hydrogen; p-n heterojunctions; semiconductor doping; silicon; solar cells; 12 percent; Si; SiGe:H; a-Si/a-Si/a-SiGe multijunction solar cells; a-SiGe:H; bottom cell; buffer layer; conversion efficiency; i-layer; long-term stability; optical gap; Buffer layers; Hydrogen; Impurities; Optical buffering; Optical films; Photovoltaic cells; Plasma materials processing; Plasma stability; Radio frequency; Substrates;
Conference_Titel :
Photovoltaic Specialists Conference, 1993., Conference Record of the Twenty Third IEEE
Conference_Location :
Louisville, KY
Print_ISBN :
0-7803-1220-1
DOI :
10.1109/PVSC.1993.347114
