Bismuth-catalyzed and doped silicon nanowires for one-pump-down fabrication of radial junction solar cells

Silicon nanowires (SiNWs) are becoming a popular choice to develop a new generation of radial junction solar cells. We here explore a bismuth- (Bi-) catalyzed growth and doping of SiNWs, via vapor-liquid-solid (VLS) mode, to fabricate amorphous Si radial n-i-p junction solar cells in a one-pump-down and low-temperature process in a single chamber plasma deposition system. We provide the first evidence that catalyst doping in the SiNW cores, caused by incorporating Bi catalyst atoms as n-type dopant, can be utilized to fabricate radial junction solar cells, with a record open circuit voltage of V _oc = 0.76 V and an enhanced light trapping effect that boosts the short circuit current to J _sc = 11.23 mA/cm ². More importantly, this bi-catalyzed SiNW growth and doping strategy exempts the use of extremely toxic phosphine gas, leading to significant procedure simplification and cost reduction for building radial junction thin film solar cells.