Fabrication and Characterization of CH3NH3PbI3 Perovskite Photovoltaic Devices with Decaphenylcyclopentasilane Hole Transport Layers

Decaphenylcyclopentasilane (DPPS) was applied as a hole transport layer for CH3NH3PbI3 solar cells, and the photovoltaic properties were investigated. The insertion of the double DPPS layers between the perovskite crystal and the gold electrodes increased short-circuit current densities and open-circuit voltages, and the conversion efficiencies were improved. The external quantum efficiencies increased in the visible light region, and the maximum power point tracking tests under air mass 1.5 light irradiation indicated the effectiveness of the DPPS layer. Microstructural analysis showed that no PbI2 compound was formed for the DPPS-inserted perovskite, which indicates the suppression of methylammonium desorption from the perovskite crystal. The double DPPS-induced devices were also stable in air for more than 1 year, which indicates that stable DPPS can reliably transport holes and has great potential for the future solar cell materials.