Fluorescence resonance energy transfer effect enhanced high performance of Si quantum Dots/CsPbBr3 inverse opal heterostructure perovskite solar cells

CsPbBr3 based perovskite solar cells draw boosted investigation benefitting from their simplified preparation property and outstanding stability against moist and heat while the photo-electrical conversion efficiency (PCE) is still worth promotion. In addition, relatively wide band gap limits the light utilization ability of pristine CsPbBr3 which leads to insufficient photo-induced charge carrier population thereby a low photocurrent density. Herein, we for the first time demonstrate a strategy to combine crystalized Si quantum dots (QDs) with CsPbBr3 inverse opal (ID) which significantly enhances the solar energy utilization efficiency by virtue of providing an additional fluorescence resonance energy transfer (FRET) process from Si QDs to CsPbBr3 IO. Acting as donor, the emitted photoluminescence from Si QDs can be absorbed by CsPbBr3, which serves as acceptor, leading to an increased carrier population in the system. Meanwhile, the multi-dimensional heterojunction between Si QDs and CsPbBr3 IO effectively facilitates the system bulk charge transfer process. A greatly improved PCE up to 8.31% with an obviously enhanced photocurrent density up to 7.8 mA.cm(-2) can be obtained with a competitive IPCE up to 81%. This strategy provides a new alternative method to develop high-performance perovskite solar cells and other photo-electronic devices.