Solution-processed silicon/SnCl2-treated Ti3C2Tx MXene Schottky junction solar cells

In this study, a novel photovoltaic cell based on the Ti3C2Tx MXene/n-type silicon (n-Si) Schottky junction is developed by a simple solution-processed method of drop-casting the Ti3C2Tx MXene ethanol suspension onto the surface of n-Si wafers and the subsequent natural drying in air. The demonstration device with a simple configuration of Ag (top electrode)/Ti3C2Tx/n-Si/In:Ga (back electrode) delivers a power conversion efficiency (PCE) of 5.70% with a short-circuit current density (Jsc) of 20.68 mA cm−2, open-circuit voltage (Voc) of 0.530 V and fill factor (FF) of 52.0% under AM 1.5G illumination. After treating the MXene layer with the SnCl2 aqueous solution, an improved PCE to 6.95% (Jsc: 23.04 mA cm−2; Voc: 0.536 V; FF: 56.2%) can be achieved because of the reduced light reflection, improved quality of junction and electrical contact, as well as the increased carrier lifetime/suppressed carrier recombination. Given the simple device configuration, facile preparation and huge potential for performance improvement, this work is believed to provide valuable exploration of developing novel solar cells.