Two-Dimensional Ti3c2tx-Patched-Go Heterojunction as Charge Booster and Defect Passivator for Stable, Carbon-Based Inorganic Perovskite Solar Cell

Abstract

Simultaneously manipulating the interfacial energetics to boost charge extraction and passivate defective nanostructure to suppress unwanted non-radiative recombination is of great importance to increase the power conversion efficiency and long-term stability of carbon-based perovskite solar cells (C-PSCs), which requires rational design of interfacial regulator. Herein, a novel two-dimensional (2D) Ti3C2Tx MXene patched graphene oxide (GO) heterojunction is fabricated as perovskite film plaster to improve the overall photovoltaic performance of C-PSCs. Arising from the nucleophilic substitution and dehydration reaction between MXene (Ti-O-) and GO (-C=OH+), the negative-charge-centered GO induced by the oxygen-containing functional groups is healed. As a result, this heterojunction not only aligns the perovskite/carbon energy-level and provides a channel for carrier transport, but also effectively solidifies the soft perovskite lattice, universally promoting the efficiencies up to 11.07% for inorganic CsPbIBr2 C-PSC and 15.04% for CsPbI2Br C-PSC with significantly improved stability.

Keywords: All-inorganic perovskite solar cells, MXene, GO, Passivating agent