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

by Xinbo Yang, Hang Xu, Wenzhu Liu, Qunyu Bi, Lujia Xu, Jingxuan Kang, Mohamed N. Hedhili, Baoquan Sun, Xiaohong Zhang, Stefaan De Wolf
Full Paper Year: 2020 DOI: https://doi.org/10.1002/aelm.202000467

Bibliography

Yang, X., Xu, H., Liu, W., Bi, Q., Xu, L., Kang, J., Hedhili, M. N., Sun, B., Zhang, X., De, S., Atomic Layer Deposition of Vanadium Oxide as Hole‐Selective Contact for Crystalline Silicon Solar Cells. Advanced Electronic Materials 2020, 2000467.

Abstract

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 (VO) deposited by atomic layer deposition (ALD) is investigated and optimized as a potential hole‐selective contact for c‐Si solar cells. ALD VOfilms are demonstrated to simultaneously offer a good surface passivation and an acceptable contact resistivity (ρc) on c‐Si, achieving a best contact recombination current density (0) of ≈40 fA cm−2 and a minimum ρc of ≈95 mΩ.cm2. Combined with a high work function of 6.0 eV, ALD VOfilms are proven to be an effective hole‐selective contact on c‐Si. By the implementation of hole‐selective VOcontact, the state‐of‐the‐art PCE of 21.6% on n‐type c‐Si solar cells with a high stability is demonstarted. These results demonstrate the high potential of ALD VOas a stable hole‐transport layer for photovoltaic devices, with applications beyond c‐Si, such as perovskite and organic solar cells.

Keywords

Passivating contact silicon solar cell vanadium oxide