Layer-Dependent Modulation of Tungsten Disulfide Photoluminescence by Lateral Electric Fields

被引：56

作者：

He, Zhengyu ^{[1
]}

Sheng, Yuewen ^{[1
]}

Rong, Youmin ^{[1
]}

Lee, Gun-Do ^{[2
]}

Li, Ju ^{[3
,4
]}

Warner, Jamie H. ^{[1
]}

机构：

[1] Univ Oxford, Dept Mat, Oxford OX1 3PH, England

[2] Seoul Natl Univ, Dept Mat Sci & Engn, Seoul 151742, South Korea

[3] MIT, Dept Nucl Sci & Engn, Cambridge, MA 02139 USA

[4] MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA

来源：

ACS NANO | 2015年 / 9卷 / 03期

关键词：

WS2; transition metal dichalcogenides; tungsten disulfide; optoelectronics; 2D crystals; photoluminescence; IMPACT IONIZATION; DIRECT BANDGAP; MOS2; WS2; EXCITONS; TRANSITION; DIODES; ABSORPTION; EMISSION;

D O I：

10.1021/nn506594a

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Large single-crystal domains of WS2 are grown by chemical vapor deposition, and their photoluminescent properties under a lateral electric field are studied. We demonstrate that monolayer and bilayer WS2 have opposite responses to lateral electric fields, with WS2 photoluminescence (PL) substantially reduced in monolayer and increased in bilayers with increasing lateral electric field strength. Temperature-dependent PL measurements are also undertaken and show behavior distinctly different than that of the lateral electric field effects, ruling out heating as the cause of the PL changes. The PL variation in both monolayer and bilayer WS2 is attributed to the transfer of photoexcited electrons from one conduction band extremum to another, modifying the resultant recombination pathways. This effect is observed in 2D transition metal dichalcogenides due to their large exciton binding energy and small energy difference between the two conduction band extrema.

引用

页码：2740 / 2748

页数：9

共 52 条

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