Light Management via Tuning the Fluorine-Doped Tin Oxide Glass Haze-Drives High-Efficiency CsPbI_3 Solar Cells

摘要

Transparent conductive fluorine-doped tin oxide (FTO) glasses play a vital role in perovskite solar cells (PSCs) for their high conductivity and outstanding transparent properties. However, among all optical characteristics (transmittance, reflectance, and scattering) for glass, the light-scattering property (usually defined by the haze) is usually negligent. Herein, four kinds of glasses with different hazes for CsPbI3 PSCs are carefully studied. Obviously, by using optimal glass (haze of 5%, transmittance of 83%, and no antireflection layer), the short-circuit current density (J(SC)) and power conversion efficiency (PCE) of the cell are enhanced for reducing the escape of light from the solar cell. Further characterization reveals that such improvement not only originates from the comprehensive effect of the scattering from the FTO glass but also the large contrast in the imaginary part of the refractive index and the surface roughness between each layer in the PSC. Meanwhile, the effect of the presence of antireflection films on light scattering is compared. It is also found that leakage current induced by haze glass is avoided for small-area (0.09 cm(2)) PSCs usually fabricated in the laboratory.