In Situ Generating YVO4:Eu3+,Bi3+ Downshifting Phosphors in SiO2 Antireflection Coating for Efficiency Enhancement and Ultraviolet Stability of Silicon Solar Cells

Abstract

Herein, a solid strategy to prepare bifunctional SiO2 coatings (BSCs) with both antireflection and luminescence downshifting properties by in situ generating YVO4:Eu3+,Bi3+ phosphors in SiO2 antireflection coatings (ARCs) is reported. Namely, a self-prepared precursor solution of the downshifting phosphors is added to a mixture of commercial SiO2 sol solution and ethanol to uniformly coat the surface of quartz glass; therefore, a novel composite porous SiO2 coating containing in situ generated YVO4:Eu3+,Bi3+ phosphors (labeled SiO2@YVO4:Eu3+,Bi3+ coating) is formed on the glass surface after annealing. The SiO2@YVO4:Eu3+,Bi3+ BSCs can effectively convert ultraviolet (UV) region photons to visible photons that are well absorbed by silicon solar cells and have better transmittance than pure SiO2 ARC. As proof-of-concept applications, the as-prepared optimal SiO2@YVO4:Eu3+,Bi3+ coating can effectively improve the photoelectric conversion efficiency (PCE) of tunnel oxide passivated contact solar cells by 0.18%abs and decrease the UV-induced degradation value of the PCE of silicon heterojunction solar cells by 0.62%abs compared to the pure SiO2 ARC. The results demonstrate that in situ generating luminescence downshifting phosphors in the SiO2 ARC of photovoltaic glass is a promising way to improve the PCE and UV stability of silicon solar cells.