Enhancing Performance of Perovskite Solar Cells by TiCl4 Treatment of Different Concentrations

Abstract

We investigated the effects of a titanium tetrachloride (TiCl4) treatment on a nanoporous titanium dioxide (TiO2) film. The TiCl4 post-treatment forms a passivation layer that is widely known to improve the performance of solar cells. In our study, the effect of the TiCl4 post-treatment on the TiO2 electrode is proposed, and the treated film is compared to the untreated film. The TiCl4 post-treatment was performed on the substrate by hydrolyzing TiCl4 in aqueous solution. The crystalline structure was adjusted by varying the TiCl4 concentration. Interestingly, a remarkable enhancement in cell efficiency was achieved by treating the compact TiO2 layer with TiCl4, and this enhancement was the result of the effective prevention of electron hole recombination. Perovskite solar cells (PSCs) with the TiCl4 passivation layer were tested using a solar simulator (100 mW/cm(2)). PSCs containing a TiCl4 coating with a 80 mM concentration showed the highest efficiency of 13.37%, a short-circuit current of 24.94 mA/cm(2), an open-circuit voltage of 0.86 V, and a Fill factor (FF) of 52.3%.