High‐performance hole‐selective V2OX/SiOX/NiOX contact for crystalline silicon solar cells

Abstract

Abstract High work function vanadium oxide (V2OX, X < 5) is expected to induce strong upward band bending at crystalline silicon (c‐Si) surface thus selectively collect photogenerated hole‐carriers. However, the performance of c‐Si solar cells employing V2OX‐based hole‐selective contacts is still under expectation. Herein, we improve the hole‐selectivity of V2OX in combination with NiOX. The innovative V2OX/NiOX stack shows reduced contact resistivity but deteriorated minority carrier lifetime due to undesired interfacial reaction between V2OX and NiOX. Inserting an ultrathin SiOX interlayer suppresses the reaction and preserves the high work function of V2OX. A remarkable power conversion efficiency of 22.03% (fill factor of 83.07%) was achieved on p‐type c‐Si solar cells featuring a full‐area V2OX/SiOX/NiOX rear contact, which is so far the highest value reported for V2OX‐based selective contacts. Our work highlights the significance of implementing p‐type transition‐metal‐oxides to boost the selectivity of V2OX and the like.

Keywords

• crystalline silicon solar cells
• interfacial reaction
• nickel oxide
• passivating contact
• vanadium oxide