High Performance Planar Structure Perovskite Solar Cells Using a Solvent Dripping Treatment on Hole Transporting Layer

Perovskite solar cell efficiency is not only related with material properties, but also affected by the interface engineering that used in perovskite solar cells. The perovskite film/electrode interface properties play important roles in charge carrier extraction, transport, and recombination. To achieve better interface contact for the device operation, proper interlayers or surface treatment should be applied. In this study, we applied a poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) interlayer with a solvent/solution washing treatment as the hole transport layer. It showed that by the solvent/solution treatment, the PEDOT:PSS film conductivity was significantly enhanced, and hence, the charge carrier transfer efficiency was efficiently improved, and the device short-circuit current density was enlarged. Finally, the device efficiency significantly increased from 14.8% to 16.2%.