Science Advances 11, eadw3969 (2025)
Xiaoqing Chen#, Huijuan Zhao#, Ruixiang Fei, Chun Huang, Jingsi Qiao, Cheng Sun, Haiming Zhu, Li Zhan, Zehua Hu, Songlin Li, Li Yang, Zemin Tang, Lianhui Wang, Yi Shi, Wei Ji, Jian-Bin Xu, Li Gao*, Xuetao Gan* & Xinran Wang*
Abstract:
Two-dimensional (2D) materials offer strong light-matter interaction and design flexibility beyond bulk semiconductors, but an intrinsic limit is the low absorption imposed by the atomic thickness. A long-sought-after goal is to achieve complementary absorption enhancement through energy transfer (ET) to break this limit. However, it is found challenging due to the competing charge transfer (CT) process and lack of resonance in exciton states. Here, we report highly efficient ET in a 2D hybrid organic-inorganic heterostructure (HOIST) of Me-PTCDI/WS2. Resonant ET is observed leading to enhanced WS2 photoluminescence (PL) by 124 times. We identify Dexter exchange between the Frenkel state in donor and an excited 2s state in acceptor as the main ET mechanism, as supported by density functional theory calculations. We further demonstrate ET-enhanced phototransistor devices with enhanced responsivity by nearly 1000 times without sacrificing the response time. Our results expand the understanding of interlayer relaxation processes in 2D materials and open opportunities in optoelectronic devices.
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