Tailored grading profiles for enhanced performance in Dion-Jacobson perovskite solar cells with MXene contacts

Abstract

2D-perovskite has attracted notable interest for its ability to address the stability challenges related to traditional 3D-perovskite. Using proper contacts for 2D-perovskites is crucial to effectively eliminate pinhole creation and collect carriers. Therefore, in this study, MXene contacts have been employed with 2D-DJ-perovskite (DJP) solar cells to combine both benefits, resulting in enhanced stability, superior charge transport, and tunable energy levels without pinhole effects. Further, to improve efficiency and mitigate transmission-thermalization losses, this work also harnesses the remarkable tunable bandgap property of the DJ-P. The DJ-P layer's bandgap is adjusted by modifying its composition in this work. This is achieved by varying the number of inorganic layers (n) within the (PeDA)(MA)n-1PbnI3n+1, perovskite structure, ranging from 1 to 6 across the thickness of the DJ-P layer. Linear, parabolic, beta, and power law-grading profiles are employed in the DJP solar cell to determine the optimal composition for the DJ-P layer. The results demonstrate that power law grading yields the highest efficiency, reaching a maximum of 17.47 % with 1.05 V VOC.