Ambient effects on photogating in MoS2 photodetectors

被引：48

作者：

Han, Peize ^{[1
]}

Adler, Eli R. ^{[1
]}

Liu, Yijing ^{[1
]}

St Marie, Luke ^{[1
]}

El Fatimy, Abdel ^{[1
,2
]}

Melis, Scott ^{[1
]}

Van Keuren, Edward ^{[1
]}

Barbara, Paola ^{[1
]}

机构：

[1] Georgetown Univ, Dept Phys, Washington, DC 20057 USA

[2] Ecole Cent Casablanca, Casablanca 27182, Morocco

来源：

NANOTECHNOLOGY | 2019年 / 30卷 / 28期

关键词：

two-dimensional materials; photodetectors; hysteresis; GAIN;

D O I：

10.1088/1361-6528/ab149e

中图分类号：

TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

Atomically thin transition metal dichalcogenides (TMDs) are ideal candidates for ultrathin optoelectronics that are flexible and semitransparent. Photodetectors based on TMDs show remarkable performance, with responsivity and detectivity higher than 10(3) AW(-1) and 10(12) Jones, respectively, but they are plagued by response times as slow as several tens of seconds. Although it is well established that gas adsorbates such as water and oxygen create charge traps and significantly increase both the responsivity and the response time, the underlying mechanism is still unclear. Here we study the influence of adsorbates on MoS2 photodetectors under ambient conditions, vacuum and illumination at different wavelengths. We show that, for wavelengths sufficiently short to excite electron-hole pairs in the MoS2 , light illumination causes desorption of water and oxygen molecules. The change in the molecular gating provided by the physisorbed molecules is the dominant contribution to the device photoresponse in ambient conditions.

引用

页数：6

共 24 条

[1] Ambient effects on electrical characteristics of CVD-grown monolayer MoS2 field-effect transistors [J].