High-Performance WSe2 Photodetector Based on a Laser-Induced p–n Junction

作者：Jing Chen, Qiyuan Wang, Yaochen Sheng, Gaoqi Cao, Peng Yang, Yabing Shan, Fuyou Liao, Muhammad Zaheer, Wenzhong Bao, Laigui Hu, Ran Liu, Chunxiao Cong, Zhi‐Jun Qiu · 发表于：ACS Applied Materials & Interfaces · 年份：2019 · DOI：10.1021/acsami.9b13948 · 被引用次数：82 · 研究领域：2D Materials and Applications、MXene and MAX Phase Materials、Chalcogenide Semiconductor Thin Films

Two-dimensional heterojunctions exhibit many unique features in nanoelectronic and optoelectronic devices. However, heterojunction engineering requires a complicated alignment process and some defects are inevitably introduced during material preparation. In this work, a laser scanning technique is used to construct a lateral WSe 2 p–n junction. The laser-scanned region shows p-type behavior, and the adjacent region is electrically n-doped with a proper gate voltage. The laser-oxidized product WO x is found to be responsible for this p-type doping. After laser scanning, WSe 2 displays a change from ambipolar to unipolar p-type property. A significant photocurrent emerges at the p–n junction. Therefore, a self-powered WSe 2 photodetector can be fabricated based on this junction, which presents a large photoswitching ratio of 10 6, a high photoresponsivity of 800 mA W –1, and a short photoresponse time with long-term stability and reproducibility. Therefore, this selective laser-doping method is prospective in future electronic applications.