Silicon Dioxide Nanoparticles Increase the Incidence Depth of Short-Wavelength Light in Active Layer for High-Performance Perovskite Solar Cells

Due to the wavelength-dependent penetration depth of the incident light, charge carriers in perovskite solar cells (PSCs) generated by short-wavelength lights mostly populate near the surface of the perovskite active layer. Thus, these photogenerated charge carriers have to run across the entire longitudinal section of the perovskite to form current, which inevitably causes carrier loss in terms of charge recombination and reduces the photovoltaic performance. Herein, we report that the incidence depth issue of the short-wavelength light can be feasibly overcome by incorporating silica nanoparticles (SiO2 NPs) into the perovskite active layer to increase the light scattering effect. As evidenced by the systematic spectroscopic and transient photoelectric studies, SiO2 NPs not only diminish the attenuation of the short-wavelength light along the incidence direction within the volume of the perovskite active layer but also promote charge transport and suppress charge recombination. Consequently, the as-modified device exhibits a prominent short-circuit current density promotion with a power conversion efficiency of 17.83%, 17% higher than that of the reference device. More importantly, it is experimentally validated that the SiO2 NPs treatment method is viable for sustaining the photocurrent of ultrathin PSC devices, which is of dramatic academic significance in developing semitransparent and flexible modules.