Effects of TiO2 nanoparticles with different sizes on the performance of CH3NH3PbI3-xClx solar cells

TiO2/perovskite photovoltaic devices were prepared by a spin-coating using a precursor solution of CH3NH3I and lead(II) chloride in N,N−dimethylformamide. Effects of TiO2 nanoparticle addition to mesoporous TiO2 precursor solutions were investigated. The current density and conversion efficiency were increased by adding the 16 or 23 nm TiO2 nanoparticles. The crystallinity of the perovskite phase was also improved by adding the TiO2 nanoparticles.