电场调制WS<sub>2</sub>单层分子薄膜光致发光行为

费萌; 谢微

doi:10.3969/j.issn.1000-5641.202022010

电场调制WS₂单层分子薄膜光致发光行为

doi: 10.3969/j.issn.1000-5641.202022010

费萌,
谢微^,

华东师范大学物理与电子科学学院, 上海　200241

基金项目: 国家自然科学基金(11674097)

详细信息

通讯作者:
谢　微, 男, 研究员, 博士生导师, 研究方向为固态环境中光-物质相互作用及其调控. E-mail: wxie@phy.ecnu.edu.cn

中图分类号: O472.3
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- 被引次数: 0
出版历程
- 收稿日期: 2020-06-11
- 刊出日期: 2021-01-27

Electric field modulated photoluminescence from WS₂ monolayers

FEI Meng,
XIE Wei^,

School of Physics and Electronic Science, East China Normal University, Shanghai　200241, China

摘要

摘要: 二维材料已经在多个领域得到应用, 其中过渡金属硫化物(Transition metal dichalcogenides, TMDCs)因存在带隙而有望用于光电领域. 将机械剥离法制备的WS₂单层分子薄膜通过干法转移至两种微周期电极结构上, 实验发现其光致发光信号受到外加偏压的调制. 研究了常温和低温环境下外加偏压对WS₂薄膜荧光光谱信号的影响, 分析讨论了不同荧光峰强度和峰位的变化行为和物理机理. 基于外加偏压，实现对WS₂单层分子薄膜光学性能的调制, 有望在场效应晶体管、光电探测器、柔性电子器件以及异质结器件等诸多光电领域实现应用.
- 二维材料 /
- 光致发光 /
- 偏压 /
- 单层分子薄膜
Abstract: Two-dimensional materials have been used in applications across a variety of fields; transition metal dichalcogenides(TMDCs), in particular, are a candidate for use in the field of optoelectronics due to the presence of a band gap. In this paper, WS₂ monolayers prepared by micro-mechanical exfoliation are transferred to two micro-period electrode structures. We found that the photoluminescence of the material is modulated by external bias. We studied the effects of bias on the photoluminescence of the WS₂ monolayer at room temperature and low temperature. The corresponding characteristics and physical mechanisms of the photoluminescence(PL) spectra, moreover, are analyzed and discussed. With the application of bias to modulate the optical properties of the WS₂ monolayer, it is expected that the technology can be applied to many photoelectric products, including field effect transistors, photodetectors, flexible electronic devices, and heterojunction devices.
- two-dimensional materials /
- photoluminescence /
- bias /
- monolayers

HTML全文

图 1 a) WS₂单层薄膜与30 μm电极组装的实验装置在光学显微镜下的照片, 白色虚线框区为WS₂单分子层;b) 实验装置测量区域横截面示意图; 有限元算法软件Comsol模拟的电场分布图,分别是c) 30 μm和d) 10 μm的一对电极贴单层前和贴单层后的横截面电场分布及局部放大图

Fig. 1 a) Photograph of the device assembled with a WS₂ monolayer and a 30 μm electrode, the white dotted frame indicates the WS₂ monolayer; b) Schematic cross-sectional view of the measurement area of the device, the electric field distributions are simulated using Comsol Multiphysics software; Pictured here are cross-sectional electric field distributions and partial magnified views of a pair of c) 30 μm and d) 10 μm electrodes before and after attaching a monolayer

下载: 全尺寸图片幻灯片

图 2 室温下a) A处单层荧光信号随偏压变化光谱图; b) A处峰位随偏压变化散点图; c) B处单层荧光信号随偏压变化光谱图; d) B处峰位随偏压变化散点图. 箭头指示了偏压由–30 V到30 V的变化方向

Fig. 2 a) PL of monolayer at A with bias; b) Scatter plot of peak position at A with bias; c) PL of monolayer at B with bias; and d) Scatter plot of peak position at B with bias. The arrow indicates the direction of the bias change from –30 V to 30 V

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图 3 a) WS₂单层薄膜与10 μm电极组装的实验装置在光学显微镜下的照片, 白色虚线框区为WS₂单分子层;b) 激子峰荧光峰值强度随偏压的变化, ①处有降低趋势(蓝色条柱),②处有增强趋势(红色条柱), ③处无单一变化趋势(紫色条柱)

Fig. 3 a) Photograph of the device assembled with a WS₂ monolayer and a 10 μm electrode; the white dotted frame indicates the WS₂ monolayer; b) The exciton peak intensity varies with the bias; ① has a decreasing trend (blue bar), ② has an increasing trend (red bar), and ③ has a no single change trend (purple bar)

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图 4 温度10 K下: a) C处单层荧光信号随偏压变化光谱图; b) C处峰位随偏压变化散点图; c) D处单层荧光信号随偏压变化光谱图; d) D处峰位随偏压变化散点图. 箭头指示了偏压由–30 V到30 V变化方向

Fig. 4 At a temperature of 10 K: a) PL of monolayer at C with bias; b) Scatter plot of peak position at C with bias; c) PL of monolayer at D with bias; and d) Scatter plot of peak position at D with bias. The arrow indicates the direction of the bias change from –30 V to 30 V

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