Efficiency enhancement of amorphous silicon p-i-n solar cells by LP-CVD ZnO

Amorphous silicon p-i-n solar cells were deposited on "in house" developed LP-CVD zinc oxide and compared with commercially available SnO/sub 2/ (Asahi type U2) substrates. While for both front TCO materials comparably high values of the open circuit voltage (860-900 mV) and of the fill factor (72-74%) were obtained, a remarkable enhancement of the short-circuit current density could be observed for LP-CVD ZnO substrates. Optical characterizations confirm for LP-CVD ZnO a more efficient light-trapping effect, as compared to SnO/sub 2/. By applying this low-cost LP-CVD ZnO, a stabilized a-Si:H p-i-n solar cell efficiency of 9% has been achieved.