Exploration of nano-element array architectures for substrate solar cells using an a-Si:H absorber

Architectures involving Ag and transparent conducting oxide (TCO) nano-element arrays for light and photocarrier collection management in substrate solar cells are numerically explored and compared. Some architectures with TCO nano-elements are shown to perform better than the best reported Ag arrays and (1) increase J(SC) at least 57% over that of a planar 200 nm a-Si:H control, (2) attain absorber utilization <7 mg/W, and (3) have only 224 nm as the longest collection length. Photonic effects are the cause of the light trapping enhancement in these devices. While the computations were done for a-Si: H, the insight provided is equally applicable to other absorbers. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4729539]