Compact Titania Films by Spray Pyrolysis for Application as ETL in Perovskite Solar Cells

Abstract

Hybrid perovskite-based solar cells are projected as a potentially viable photovoltaic (PV) technology for large-scale implementation. The electron transport layer (ETL) should be dense and pinhole-free to facilitate efficient electron collection and transport from the perovskite layer to the anode, which is very important for achieving high-performance solar cells. In this study, a compact TiO2 layer was synthesized by a scalable spray pyrolysis technique. The effect of deposition temperature on the transparency, microstructure, and bandgap of c-TiO2 film was studied. Pinhole-free nanocrystalline films having > 85% transparency with uniform coverage was obtained on spray pyrolysis at 400°C and annealing at 450°C. Usability of the deposited films as ETL in perovskite solar cells was tested by fabricating solar cells (FTO/c-TiO2/FA0.85MA0.15Pb(I0.85Br0.15)3/CuSCN/Au) using the deposited films and comparing their performance. Cell efficiency close to 11.75% with a fill factor of 69% was obtained in the cell fabricated using the films deposited at 400°C. © 2020, The Minerals, Metals & Materials Society.