Photodetectors Based on Vertically Stacked Bi<sub>2</sub>Te<sub>3</sub>/WSe<sub>2</sub> Heterojunctions for Visible to Near-Infrared Photodetection
Chaoyi Zhang, Silu Peng, Yuchao Wei, Chunyu Li, Jiayue Han, Hongxi Zhou, Yadong Jiang, Jun Wang
Abstract
Bismuth telluride (Bi 2 Te 3 ) presents a promising option for producing high-performance semiconductor devices such as transistors and photodetectors thanks to its intriguing electrical properties as a topological insulator (TI). This study focuses on the precise nanoscale physical vapor deposition (PVD) growth of two-dimensional (2D) Bi 2 Te 3 nanosheets and investigates their potential in high-performance photodetectors. In order to maximize the performance of Bi 2 Te 3 nanosheet devices, we constructed a Bi 2 Te 3 /WSe 2 heterojunction by a vertical stacking method, and the devices exhibited obvious current rectification behavior in the dark, effectively realizing the detection from visible light to near-infrared wavebands photodetection with excellent performance, including high responsivity ( R = 7.6 A/W), the outstanding specific detectivity ( D * = 3.01 × 10 11 Jones), and fast response time (214/276 μs). The results of this work not only help to understand the PVD growth mechanism of Bi 2 Te 3 nanosheets but also provide ideas for the construction of 2D Bi 2 Te 3 nanostructured optoelectronic heterojunction devices.