Highly Efficient Charge Transfer between Perovskite Nanocrystals and g‐C3N4 Nanosheets

Abstract

Benefiting from the bandgap engineering implemented on two different structures, heterostructures have significantly extended the applications of semiconductors. Thus, understanding the energy/charge transfer of heterostructures is very important for achieving high‐performance devices. Herein, heterostructures with potential applications in solar harvesting are constructed by CsPb(BrxI1−x)3 perovskite nanocrystals (PNCs) emitting at 640 nm and g‐C3N4 nanosheets (CN) with fluorescence covering from 450 to 550 nm. The fluorescence of CsPb(BrxI1−x)3 PNCs is substantially quenched by CN. Moreover, the photodegradation of CsPb(BrxI1−x)3 is remarkably hastened when interacting with the CN, indicating efficient charge transfer in the heterostructures, which is further verified by time‐resolved photoluminescence (PL) and temperature‐dependent PL results. The charge transfer lifetime is much shorter than the radiative recombination lifetime and defect trapping lifetime, ensuring quick charge transfer from PNCs to CN before radiative recombination and defect trapping, resulting in high charge transfer efficiency up to 98.16%. This work sheds light on heterostructures based on PNCs, which will facilitate their future application in photocatalysts, light‐emitting diodes, and photodetectors.