Understanding the pathways toward improved efficiency in MXene-assisted perovskite solar cells

Abstract

A large and rapidly expanding class of two-dimensional (2D) metal carbides, nitrides, and carbonitrides called MXenes, with their interesting photovoltaic applications and tunable surface termination, has found a vast range of applications in improving the performance of perovskite solar cells (PSCs). By doing simulations, we report the influence of adding Ti₃C₂T_x MXene into the absorber layer, and at the interfaces in a PSC, to achieve physical understanding about its impact on the improvement of the performance of the PSC. In this work, the considered architecture contains the methylammonium lead triiodide (MAPbI₃) absorber layer, TiO₂ electron transport layer, and Spiro-OMeTAD hole transport layer. The simulations show that the addition of Ti₃C₂T_x to the halide perovskite and TiO₂ layers induces an electric dipole at the interfaces that can change the band alignment between the charge transfer layers and absorber layer. The combined action of the work function tuning and interface engineering can modify the electric field distribution in the layers, which can increase the built-in potential, affect the photocurrent and current density, and finally improve the performance of MXene-modified PSCs with respect to reference cells without MXene. This work provides a theoretical discussion to display the promising role of MXenes to be used in PSCs to improve their performances.