Category: Handbook of the Physics ofThin-Film Solar Cells

A-Si/a-SiGe Tandem and a-Si/a-SiGe/a-SiGe Triple-Junction Solar Cells

Dual-junction a-Si/a-Si (same band-gap tandem) solar cells have lower material cost (no GeH4) than tandem cells using a-SiGe, and have slightly higher efficien­cies (0.5-1 % absolute) than a-Si single junction cells. Same band-gap a-Si/a-Si tandems have been in production for decades. Multiband-gap dual junction (a-Si/a – SiGe: Doughty and Gallagher 1990, or a-Si/nc-Si Yamamoto et […]

Optical Design of a-Si:H and nc-Si:H Solar Cells

Back reflectors and substrate texturing are used to improve the power output of most thin film solar cells. Figure 41.6a shows the “quantum efficiencies” measured for a 250-nm-thick a-Si:H solar cell with varying texturing and back reflectors (Hegedus et al. 1996), along with absorptances calculated from the optical absorption coeffi­cient spectrum for a-Si:H. The dashed […]