Preparation and performance of perovskite solar cells with two dimensional MXene as active layer additive

In this paper, two-dimensional titanium carbide (Ti3C2Tx) and vanadium carbide (V2CTx) MXene with appropriate mass content are incorporated into PbI2 precursor solution to fabricate perovskite film via onestep coating method. The effects of the addition of MXene with different mass ratio on the morphology, crystallinity, light absorption property and stability of the CH3NH3PbI3 film and the photovoltaic performance and stability of the corresponding devices are further investigated. The results demonstrate that the introduction of Ti3C2Tx and V2CTx additive can improve the morphology of perovskite film, increase the grain size of perovskite film, enhance the hydrophobicity of the perovskite layer. As a result, improved photovoltaic performance can be achieved. By modifying the proportion of additives, the power conversion efficiency (PCE) of V2CTx MXene modified solar cells is better than those of the devices with Ti3C2Tx additive and the pristine one. Compared with the control device without additive, perovskite solar cells incorporating V2CTx additive with an optimized concentration of 0.0013 wt% achieve a PCE of 17.61% (increased by 17%). Moreover, for perovskite film incorporating V2CTx additive, unique morphology with uniform grain size and ordered layered crystal particle can be noted. This means the V2CTx additive can regulate the perovskite crystal film growth. In addition, the V2CTx additive incorporated devices can retain 68.29% of the initial PCE after 15 days, which is higher than the devices without additives (by 9.69%) and with Ti3C2Tx as additive (by 47.16%), owing to the better crystallinity and higher quality of perovskite film. Our work provides an effective method for improving performance of perovskite solar cells and expands the applications areas of V2CTx in photovoltaics. (C) 2022 Elsevier B.V. All rights reserved.