Passivating/hole-selective contacts based on V2O5/SiOx stacks deposited at ambient temperature

Abstract N-Type crystalline silicon (c-Si) heterojunctions with V 2 O 5 /SiO x stacks as passivating/hole-selective contacts are reported. SiO x interlayers were prepared by low temperature (T 2 O 5 at ambient temperature. A high surface passivation, with an implied open-circuit voltage (i-V OC ) of 675 mV, is obtained for a 2.1 nm thick SiO x interlayer ‘naturally’ formed during V 2 O 5 evaporation. X-ray photoelectron spectroscopy analyses indicate a sub-stoichiometric configuration (SiO x~1.4 ), whereas hydrogen-containing species like Si–OH and Si–(O 3 H) are identified by secondary ion-mass spectroscopy as possible contributors to dangling bond passivation. A conversion efficiency of 16.5% (V OC = 642 mV) is attained, confirming the potential of these dopant-free novel structures for c-Si photovoltaics.