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

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.