In situ processed gold nanoparticle-embedded TiO2 nanofibers enabling plasmonic perovskite solar cells to exceed 14% conversion efficiency

Abstract

We have demonstrated organometallic perovskite solar cells (PSCs) based on Au decorated TiO₂ nanofibers and methylammonium lead iodide (MAPbI₃). A power conversion efficiency of 14.92% was achieved, which is significantly higher than that of conventional mesoporous (mp) TiO₂, as well as TiO₂ nanofiber-based devices. The present synthetic process provides new opportunities for the development of efficient plasmonic PSCs based on metal oxide nanofibers. Solar cells based on these architectures exhibit a short-circuit current density J_SC of 21.63 ± 0.36 mA cm⁻², V_OC of 0.986 ± 0.01 V and fill factor of 70% ± 3%, which provide a power conversion efficiency of 14.92% ± 0.33% under standard AM 1.5 conditions. The results of time-resolved photoluminescence (TRPL) spectroscopy and solid-state impedance spectroscopy (ssIS) revealed that PSCs based on Au-decorated TiO₂ nanofibers exhibit a low recombination rate. The present results are much higher than those for reported PSCs based on a Au@TiO₂ electron-transporting layer (ETL).