Beneficial effect of a low deposition temperature of hot-wire deposited intrinsic amorphous silicon for solar cells

Hot-wire deposited amorphous silicon is an excellent material for incorporation as the absorbing layer in solar cells. We show the beneficial effect of a low deposition temperature of hot-wire deposited intrinsic amorphous silicon for solar cells. The influence of a few specific deposition parameters on the material properties was investigated. It is shown that both the filament history and the deposition pressure are crucial parameters for the material quality. Optimized material, deposited at 250 °C, was incorporated in efficient single- and multijunction solar cells on flexible stainless steel substrates. The n-i-p structure was used to avoid any influence of TCO- and p-layer degradation, which is otherwise present in p-i-n structures. The cells have a high open-circuit voltage and high fill factor, clearly showing the improved performance of hot-wire deposited amorphous silicon made at moderate temperature.