학술논문

Room-Temperature Near-Infrared and Self-Powered Photodetectors Based on Graphite/WTe2/Ge Mixed van der Waals Heterostructure
Document Type
Periodical
Source
IEEE Transactions on Electron Devices IEEE Trans. Electron Devices Electron Devices, IEEE Transactions on. 70(5):2358-2363 May, 2023
Subject
Components, Circuits, Devices and Systems
Engineered Materials, Dielectrics and Plasmas
Germanium
Heterojunctions
Substrates
Silicon
Graphite
Absorption
Photonic band gap
Germanium (Ge)
mixed van der Waals (vdWs) heterojunction
near-infrared photodetection
Schottky photodetector (PD)
Weyl semimetal (WSM) WTe2
Language
ISSN
0018-9383
1557-9646
Abstract
Herein, we report a graphite (Gr)/WTe2/Ge mixed-dimensional van der Waals (vdWs) heterojunction-based Schottky photodetector (PD) for self-powered near-infrared detection. Notably, the fabricated device can respond to the wide spectrum of 400–2200 nm with the optimal wavelength around 1550 nm. In particular, it exhibited remarkable photovoltaic characteristics with a maximum responsivity of 2.3 A/W, a specific detectivity of $3.4\times 10^{{10}}$ Jones, and a light ${I}_{ \mathrm{\scriptscriptstyle ON}}/{I}_{ \mathrm{\scriptscriptstyle OFF}}$ ratio of over $10^{{3}}$ with a fast response speed of 4.4/ $8.6 \mu \text{s}$ under 1550 nm. Moreover, a clear single-point image of “SCNU” in the self-driven mode can be obtained under 1550 nm illumination. The above results suggest that the constructed Gr/WTe2/Ge PD shows great potential in the field of ultrafast near-infrared detection and high-resolution imaging.