WSe2 Photovoltaic Device Based on Intramolecular p–n Junction

• DOI: 10.1002/smll.201805545
• Publication Date: 2019-02-20T22:01:19Z
• Authors: Yicheng Tang; Zhen Wang; Peng Wang; Feng Wu; Yueming Wang; Yunfeng Chen; Hailu Wang; Meng Peng; Chongxin Shan; Zhihong Zhu; Shiqiao Qin; Weida Hu
• Keywords: p–n junction; Quantum Efficiency; Open-circuit voltage

High quality p-n junctions based on 2D layered materials (2DLMs) are urgent to exploit, because of their unique properties such as flexibility, high absorption, and tunability which may be utilized in next-generation photovoltaic devices. Based transfer technology, large amounts vertical heterojunctions 2DLMs investigated. However, the complicated fabrication process inevitable defects at interfaces greatly limit application prospects. Here, an in-plane intramolecular WSe2 junction is realized, n-type region p-type chemically doped by polyethyleneimine electrically back-gate, respectively. An ideal factor 1.66 achieved, proving realized this method. As a detector, device possesses responsivity 80 mA W-1 (≈20% external quantum efficiency), specific detectivity over 1011 Jones fast response features (200 µs rising time 16 falling time) zero bias, simultaneously. Moreover, open-circuit voltage 0.38 V power conversion efficiency ≈1.4% also promises its potential microcell applications.