Heterostructure Silicon Solar Cells with Enhanced Power Conversion Efficiency Based on Si /Ni³⁺ Self-Doped NiO ...

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 Ni³⁺ self-doped NiO film is obtained by tuning the reactive oxygen atmosphere to construct the optimized c-Si/NiO heterostructure band alignment. A thin SiO interlayer was further introduced to reduce the defect of the c-Si/NiO interface with the UV-ozone (UVO) treatment. The constructed p-type c-Si/SiO /NiO /Ag solar cell exhibits an increase in the open voltage from 586 to 611 mV and achieves a 19.2% conversion efficiency.