Perovskite/La-BDC heterojunction enhances the performance of carbon-based perovskite solar cells

Carbon-based Perovskite Solar Cells (C-PSCs) present a promising avenue for enhancing the stability and commercialization of PSCs. However, the power conversion efficiency (PCE) of C-PSCs still lags behind that of metal-based PSCs. In this study, La-BDC (La-MOF prepared by La 3+ and ligand H 2 BDC) has successfully synthesized using a simple hydrothermal method and then directly introduced into CH 3 NH 3 PbI 3 (MAPbI 3 ) perovskite precursor solution to prepare perovskite/La-BDC heterojunction structure with remarkable properties in light absorption , hydrophobicity , and crystallinity . By incorporating this structure, the PCE of C-PSCs with an FTO/SnO 2 /MAPbI 3 /La-BDC/Carbon architecture was effectively enhanced. The presence of C O functional group in La-BDC effectively reduced interface defects while improving carrier separation efficiency, and successfully passivated the free Pb 2+ ions within the perovskite. Remarkably, the La-BDC-based device achieved a superior PCE of 14.95%, surpassing the pristine device's PCE by an impressive margin of 20.37%. Moreover, even after a 31 days period of air storage (temperature range of 15–25℃, humidity range of 15–30%), the La-BDC-based devices maintained over 90% of the initial performance, demonstrating excellent stability. This study provides a facile and effective strategy for improving the PCE and stability of C-PSCs through implementing a La-BDC heterojunction structure， and provides a new idea for MOF materials in the field of PSCs.