High-responsivity, self-driven photodetectors based on monolayer WS<sub>2</sub>/GaAs heterojunction
Kuilong Li, Wenjia Wang, Jianfei Li, Wenxin Jiang, Min Feng, Yang He
Abstract
Constructing two-dimensional (2D) layered materials with traditional three-dimensional (3D) semiconductors into complex heterostructures has opened a new platform for the development of optoelectronic devices. Herein, large-area high performance self-driven photodetectors based on monolayer <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m1"> <mml:mrow> <mml:msub> <mml:mi>WS</mml:mi> <mml:mn>2</mml:mn> </mml:msub> <mml:mo>/</mml:mo> <mml:mi>GaAs</mml:mi> </mml:mrow> </mml:math> heterostructures were successfully fabricated with a wide response spectrum band ranging from the ultraviolet to near-infrared region. The detector exhibits an overall high performance, including high photoresponsivity of 65.58 A/W at 365 nm and 28.50 A/W at 880 nm, low noise equivalent power of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m2"> <mml:mrow> <mml:mn>1.97</mml:mn> <mml:mo>×</mml:mo> <mml:msup> <mml:mn>10</mml:mn> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>15</mml:mn> </mml:mrow> </mml:msup> <mml:mtext> </mml:mtext> <mml:mi mathvariant="normal">W</mml:mi> <mml:mo>/</mml:mo> <mml:msup> <mml:mi>Hz</mml:mi> <mml:mrow> <mml:mn>1</mml:mn> <mml:mo>/</mml:mo> <mml:mn>2</mml:mn> </mml:mrow> </mml:msup> </mml:mrow> </mml:math> , high detectivity of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m3"> <mml:mrow> <mml:mn>4.47</mml:mn> <mml:mo>×</mml:mo> <mml:msup> <mml:mn>10</mml:mn> <mml:mn>12</mml:mn> </mml:msup> <mml:mtext> </mml:mtext> <mml:mi>Jones</mml:mi> </mml:mrow> </mml:math> , and fast response speed of 30/10 ms. This work suggests that the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m4"> <mml:mrow> <mml:msub> <mml:mi>WS</mml:mi> <mml:mn>2</mml:mn> </mml:msub> <mml:mo>/</mml:mo> <mml:mi>GaAs</mml:mi> </mml:mrow> </mml:math> heterostructure is promising in future novel optoelectronic device applications, and also provides a low-cost, easy-to-process method for the preparation of 2D/3D heterojunction-based devices.