Adjustment of the energy transfer pathway in nanoplatelet-organic molecule hybrids through spectral overlap

Abstract

Two-dimensional (2D) CsPbBr₃ nanoplatelets (NPLs) have garnered significant attention because of their promising applications in optoelectronics and photocatalysis. Despite substantial progress in the development of these materials, a critical gap remains. This gap is particularly evident in the understanding of singlet and triplet energy transfer mechanisms within hybrid systems that incorporate organic molecules, such as Rose Bengal (RoseB). Using a combination of steady-state and transient absorption spectroscopy, we demonstrate that both singlet and triplet energy transfer are feasible within this hybrid system. Our findings reveal that the efficiency of these processes highly depends on the CsPbBr₃ NPLs and RoseB spectral overlap, which is in turn influenced by the NPLs thickness. The energy transfer rate of the system increases with increasing spectral overlap, as does the energy transfer efficiency. As the NPLs thickness increases, a higher proportion of singlet energy transfer and a corresponding decrease in triplet energy transfer occur. Our results offer new strategies for controlling energy transfer pathways, which can enhance the design and optimization of high-performance optical devices and improve the efficiency of photocatalytic systems.