Zhang Si-Wei, Ma Fulong, Jiang Jinhui, Wang Zaiyu, Qiu Zijie, Lam Jacky W Y, Wei Guodan, Zhao Zheng, Tang Ben Zhong
Department of Chemistry and the Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Kowloon, 999077, Hong Kong, China.
School of Science and Engineering, Shenzhen Institute of Aggregate Science and Technology, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen), Guangdong 518172, China.
Precis Chem. 2023 Jul 21;1(6):357-362. doi: 10.1021/prechem.3c00067. eCollection 2023 Aug 28.
Due to their excellent stability and layer-dependent photoelectronic properties, transition metal dichalcogenides (TMDs) are one of the most extensively studied two-dimensional semiconductor materials in the postgraphene era. However, its low luminescence quantum yield limits its application in displays, lighting, and imaging. Here, a 1,4,5,8,9,11-hexaazatriphenylenehexacarbonitrile (HATCN) layer was grown on the surface of chemical vapor deposition (CVD)-grown monolayer molybdenum disulfide (MoS) by vacuum evaporation, which increased the photoluminescence intensity of MoS by 15 times. The enhanced luminescence originates from the charge transfer from the conduction band of MoS to the lowest unoccupied molecular orbital (LUMO) of HATCN, which suppresses the emission of the negatively charged exciton (trion) while increasing the emission of the neutral exciton. Temperature-dependent fluorescence and Raman spectra demonstrate the feasibility of organic-inorganic hybrid heterojunctions for regulating excitons. This facile and practical organic-inorganic hybrid heterojunction can elevate TMD applications, such as light-emitting diodes.
由于具有出色的稳定性和层依赖的光电特性，过渡金属二硫属化物（TMDs）是后石墨烯时代研究最为广泛的二维半导体材料之一。然而，其低发光量子产率限制了它在显示、照明和成像领域的应用。在此，通过真空蒸发在化学气相沉积（CVD）生长的单层二硫化钼（MoS）表面生长了一层1,4,5,8,9,11-六氮杂三亚苯六腈（HATCN），这使得MoS的光致发光强度提高了15倍。增强的发光源于从MoS的导带向HATCN的最低未占据分子轨道（LUMO）的电荷转移，这抑制了带负电荷的激子（三重态激子）的发射，同时增加了中性激子的发射。温度依赖的荧光和拉曼光谱证明了有机-无机杂化异质结调控激子的可行性。这种简便实用的有机-无机杂化异质结能够提升TMDs的应用，如发光二极管。
