Proceedings of International Conference on Perovskite Thin Film Photovoltaics and Perovskite Photonics and Optoelectronics (NIPHO20)
DOI: https://doi.org/10.29363/nanoge.nipho.2020.098
Publication date: 25th November 2019
Perovskite solar cells (PSCs) are one of the most promising new-generation photovoltaic (PV) technologies combining simple, solution process, fabrication techniques and efficiencies comparable to other well established PV. In this work, we use the Ti3C2TX MXene with various termination groups (TX) to tune the work function of the perovskite absorber and the electron transport layer (ETL), to engineer the perovskite/ETL interface and to improve cell efficiency. Ultraviolet photoemission spectroscopy measurements and Density Functional Theory calculations show that the addition of Ti3C2TX to halide perovskite and ETL permits to tune the materials’ WFs, without affecting other electronic properties. The non linear relation between terminal group mix and the WF is carried out for both MXenes and MXenes/perovskite [1]. In addition, we show that the dipole induced by the Ti3C2TX at the perovskite/ETL interface can be used to change the band alignment between these layers. The combined action of WF tuning and interface engineering can lead to substantial performance improvements in MXene-modified PSCs in direct configuration, as shown by the 26% increase of power conversion efficiency and hysteresis reduction with respect to reference cells without MXene.[2] Similar results have been obtained also for inverted configuration where a NiO/perovskite+MXenes/PCBM stack is used.[3]