Chen Xiaoqing, Zhao Huijuan, Fei Ruixiang, Huang Chun, Qiao Jingsi, Sun Cheng, Zhu Haiming, Zhan Li, Hu Zehua, Li Songlin, Yang Li, Tang Zemin, Wang Lianhui, Shi Yi, Ji Wei, Xu Jian-Bin, Gao Li, Gan Xuetao, Wang Xinran
National Laboratory of Solid State Microstructures, School of Electronic Science and Engineering and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
Key Laboratory of Light Field Manipulation and Information Acquisition, Ministry of Industry and Information Technology, and Shaanxi Key Laboratory of Optical Information Technology, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an 710129, China.
Sci Adv. 2025 Sep 5;11(36):eadw3969. doi: 10.1126/sciadv.adw3969.
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/WS. Resonant ET is observed leading to enhanced WS photoluminescence (PL) by 124 times. We identify Dexter exchange between the Frenkel state in donor and an excited 2 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.
二维（2D）材料具有比体相半导体更强的光与物质相互作用以及设计灵活性，但一个内在限制是原子厚度导致的低吸收率。一个长期追求的目标是通过能量转移（ET）实现互补吸收增强以突破这一限制。然而，由于竞争的电荷转移（CT）过程以及激子态缺乏共振，这一目标颇具挑战性。在此，我们报道了在Me-PTCDI/WS的二维有机-无机异质结构（HOIST）中实现的高效能量转移。观察到共振能量转移导致WS的光致发光（PL）增强了124倍。我们确定供体中的弗伦克尔态与受体中的激发2态之间的德克斯特交换为主要的能量转移机制，密度泛函理论计算支持了这一点。我们进一步展示了能量转移增强的光电晶体管器件，其响应度提高了近1000倍，且不牺牲响应时间。我们的结果扩展了对二维材料中层间弛豫过程的理解，并为光电器件带来了机遇。
