Dependence of a-Si solar cell Voc on deposition temperature

The authors have investigated variations in the a-Si deposition process to achieve a high V_oc a-Si solar cell to be used as the top cell of a triple-junction stacked solar cell. In this investigation, a-Si n-i-p solar cells were deposited on stainless steel substrates in a multichamber RF PECVD deposition system. Different deposition conditions were explored for the intrinsic a-Si layer with the goal of obtaining high V_oc. After process optimization, the authors have achieved a V_oc of 1.04 V for a-Si n-i-p solar cells with the intrinsic layer deposited at 150°C at high hydrogen dilution. This V_oc is higher than any V_oc achieved for a single-junction solar cell using a-SiC as the intrinsic layer. This high V_oc a-Si material is a better choice for the top cell i layer of a triple-junction a-Si alloy solar cell than high bandgap a-SiC alloys