Charge Behavior Modulation by Titanium-Carbide Quantum Dots and Nanosheets for Efficient Perovskite Solar Cells

Abstract Efficient charge transfer with suppressed charge recombination is crucial for perovskite solar cells (PSCs) with high photovoltaic performance. Herein, Ti3C2 quantum dots (QDs) are introduced into the perovskite layer, and Ti3C2 nanosheets are inserted into the TiO2 electron transport layer. The results confirm that the incorporation of Ti3C2 QDs can effectively reduce the defect state concentration of perovskite films, and the Ti3C2 nanosheets can improve the electron mobility of the electron transport layer (ETL). By taking advantages of zero- and two-dimensional Ti3C2, the performance of perovskite solar cell achieves an enhancement of photoelectric conversion efficiency (PCE) from 12.0% to 17.1%, along with reduced hysteresis effect of the device. This work explores a promising strategy to exploit MXenes in the application of PSCs.