Calculation of photovoltaic characteristics and materials selection for low-band-gap cells of multi-structure solar cell system

✍ Scribed by Yoshikazu Takeda; Akihiro Wakahara; Akio Sasaki

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 637 KB
• Volume: 26
• Category: Article
• ISSN: 0927-0248
• DOI: 10.1016/0927-0248(92)90128-c

✦ Synopsis

Photovoltaic characteristics of low-band-gap cells for a high efficiency multi-structure solar cell system are calculated using a precise modeling of the absorption coefficient for direct and indirect transitions in the absorption and window layers. Taking the AlGaAs/GaAs cell as the intermediate-band-gap cell, several materials and device structures for the low-band-gap cell are investigated to give the highest conversion efficiency at one sun AM0. The materials are chosen from those currently available that can be grown by conventional growth techniques with a high enough quality and a large enough area. It is predicted for the solar spectrum wavelength region longer than 0.87 I~m at one sun AM0 that the cell with In0.53Ga0.a7As as the absorption layer can give an efficiency of 5.84% with a perfect AR-coating and an In0.52A10.a8As window, and that the cell with In0.67Ga0.33As0.71P0.29 as the absorption layer can give an efficiency of 6.32% with a perfect AR-coating and In0.52A10.a8As window. It is shown that simpler structures with a very thin InP window layer also give similar efficiencies.