Investigating the Influence and Charge Carrier Dynamics of PCA-MXene-Integrated Colloidal Quantum Dot Photovoltaics through Transient Absorption Analysis

Abstract

Lead sulfide colloidal quantum dot (PbS-CQD) have attracted significant interest due to their tunable bandgap, multi-exciton generation effect and ambient solution processing, which makes them photovoltaic materials for low-cost, large-area and flexible solar cells. Despite there are several challenges, the Fermi level mismatch between the PbS-CQD layer and hole transport layer results in the formation of energy bands that are not conducive to efficient hole collection, and the presence of numerous surface cracks in the thiol-treated CQD layer diminished device performance. To address these issues, we develop a polycatechol functionalized MXene (PCA-MXene) as an interlayer to enhance hole extraction. The effectiveness of PCA-MXene was validated through measurements utilizing time-resolved photoluminescence (TRPL) and transient absorption (TA) spectroscopy. By analyzing the charge carrier dynamics, we obtain hole transfer in the positive impact of PCA-MXene-based CQD solar cells.