Atomic Layer Deposition of Vanadium Oxide as Hole-Selective Contact for Crystalline Silicon Solar Cells

High carrier recombination loss at the contact regions has become the dominant factor limiting the power conversion efficiency (PCE) of crystalline silicon (c-Si) solar cells. Dopant-free carrier-selective contacts are being intensively developed to overcome this challenge. In this work, vanadium oxide (VOx) deposited by atomic layer deposition (ALD) is investigated and optimized as a potential hole-selective contact forc-Si solar cells. ALD VO(x)films are demonstrated to simultaneously offer a good surface passivation and an acceptable contact resistivity (rho(c)) onc-Si, achieving a best contact recombination current density (J(0)) of approximate to 40 fA cm(-2)and a minimum rho(c)of approximate to 95 m omega.cm(2). Combined with a high work function of 6.0 eV, ALD VO(x)films are proven to be an effective hole-selective contact onc-Si. By the implementation of hole-selective VO(x)contact, the state-of-the-art PCE of 21.6% onn-typec-Si solar cells with a high stability is demonstarted. These results demonstrate the high potential of ALD VO(x)as a stable hole-transport layer for photovoltaic devices, with applications beyondc-Si, such as perovskite and organic solar cells.