Enhancing of charge transfer efficiency from a perovskite CH3NH3PbI3 film in a layer of titanium dioxide in the presence of Ag/SiO2 nanoparticles

Abstract

Using of localized plasmon resonance (LPR) in metal nanoparticles (NPs) is one of the promising directions for increasing of perovskite solar cells efficiency [1, 2]. Metal NPs coated dielectric shell can be used to exclude the contribution of the NPs to the total electrical conductivity of a perovskite films. The influence of LPR in the "core-shell" NPs on the process of charge transfer from a perovskite CH3NH3PbI3 layer to TiO2 layer is studied in the work. Samples with ITO−TiO2−CH3NH3PbI3 layers structure film were fabricated. Ti-Nanoxide BL/SC (Solaronix) paste were used for fabrication a compact TiO2 layers. CH3NH3PbI3 films synthesized by a one-step method [3]. 0.1 wt% Ag/SiO2 NPs with respect to the mass of the perovskite was added to a solution of a CH3NH3I•PbI2•DMSO adduct in dimethylformamide. The diameter of Ag NPs was 5 nm, and the radius of the dielectric shell (SiO2) was 2.5 nm. The addition of NPs to the adduct solution leads to the formation of the perovskite films with a lower optical density than the perovskite without NPs. A decrease in the intensity of the luminescence, and a blue shift in wavelengths of the luminescence intensity maximum is observed for the CH3NH3PbI3 films with NPs compared to this parameters for CH3NH3PbI3 films without NPs. The luminescence lifetime also decreases for the CH3NH3PbI3 with NPs. The intensity maximum of the luminescence kinetics for CH3NH3PbI3 with NPs has a time delay (0.05 - 0.1 ns) in comparison with the maximum luminescence intensity of perovskite without NPs. These results indicate an increase in the efficiency of charge transfer from perovskite to TiO2 in the presence of Ag/SiO2 NPs.