Heterostructure Silicon Solar Cells with Enhanced Power Conversion Efficiency Based on Si(x)/Ni(3+) Self-Doped NiO(x) Passivating Contact

[Image: see text] Developing efficient crystalline silicon/wide-band gap metal-oxide thin-film heterostructure junction-based crystalline silicon (c-Si) solar cells has been an attractive alternative to the silicon thin film-based counterparts. Herein, nickel oxide thin films are introduced as the hole-selective layer for c-Si solar cells and prepared using the reactive sputtering technique with the target of metallic nickel. An optimal Ni(3+) self-doped NiO(x) film is obtained by tuning the reactive oxygen atmosphere to construct the optimized c-Si/NiO(x) heterostructure band alignment. A thin SiO(x) interlayer was further introduced to reduce the defect of the c-Si/NiO(x) interface with the UV–ozone (UVO) treatment. The constructed p-type c-Si/SiO(x)/NiO(x)/Ag solar cell exhibits an increase in the open voltage from 586 to 611 mV and achieves a 19.2% conversion efficiency.