Enhanced fluorescence resonance energy transfer in CsPbBr3 quantum dot-rhodamine 640 molecule hybrid system: Toward high-efficiency and high-rate capability

Abstract

The fluorescence resonance energy transfer (FRET) process plays a crucial role in improving the efficiency of optoelectronic and photosynthetic devices. CsPbBr₃ perovskite quantum dot (QD) serves as efficient photon absorbers and exciton generators, thus offering the potential to enhance FRET performance. However, a high-efficiency FRET process with high-rate capability has not been achieved in the CsPbBr₃ perovskite QD-based system. Herein, we reported that the FRET process is improved in CsPbBr₃ perovskite QD-rhodamine 640 molecule hybrid system in n-hexane solution. This phenomenon stems from an increased number of adsorbed acceptor and a decreased distance between donor and acceptor. When the adsorbed number reached 4.2, a near-unity FRET efficiency of 99.3 % was achieved. Meanwhile, femtosecond transient absorption spectroscopy reveals that the FRET process exhibits a high-rate capability of 0.57 ps⁻¹. Consequently, this research will stimulate the development of high-performance light-emitting device of perovskite-based system.