Analysis of photoluminescence behavior of high-quality single-layer MoS2  

作　　者：Lu Xu Liyun Zhao Yunsong Wang Mingchu Zou Qing Zhang Anyuan Cao 

机构地区：[1]Department of Materials Science and Engineering,College of Engineering Peking University,Beijing 100871,China

出　　处：《Nano Research》2019年第7期1619-1624,共6页纳米研究（英文版）

基　　金：supported by the National Natural Science Foundation of China (No.51672005);the National Key R&D Program of China (No.2016YFE0127300).

摘　　要：The ability to tailor and enhance photoluminescence (PL) behavior in two-dimensional (2D) transition metal dichalcogenides (TMDCs) such as molybdenum disulfide (MoS2) is significant for pursuing optoelectronic applications.To achieve this,it has been essential to obtain high-quality single-layer MoS2 and fully explore its intrinsic PL performance.Here,we fabricate single-layer MoS2 by a thermal vapor sulfurization method in which a pre-deposited molybdenum trioxide (MoO3) thin film is sulfurized over a short period (for several minutes) to turn into MoS2.These as-grown MoS2 crystals show quite strong PL,which is about one order of magnitude higher than that of chemical-vapor-deposited MoS2.Temperature- and power-dependent spectroscopy measurements disclose the apparent influence of sulfur (S) vacancies on the PL behavior and the noticeable free-to-bound exciton recombinations in the luminescence process.The fact that PL intensity of the sample in vacuum sharply lowered down relative to in air reveals that the high PL is facilitated by molecular adsorption on S vacancies in air.And multi-channel decay processes coupled with S vacancies are revealed in the time-resolved PL spectroscopy.In our work,single-layer MoS2 with high PL is synthesized and its defect-induced PL features are analyzed,which is of great importance for developing advanced nano-electronics and optoelectronics based on 2D structures.

关 键 词：MOS2 PHOTOLUMINESCENCE thermal vapor SULFURIZATION S VACANCY 

分 类 号：O4[理学—物理]