Recent Progress on Localized Field Enhanced Two‐dimensional Material Photodetectors from Ultraviolet—Visible to Infrared

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 13; no. 35
• Main Authors: Wang, Jianlu, Fang, Hehai, Wang, Xudong, Chen, Xiaoshuang, Lu, Wei, Hu, Weida
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01-09-2017
• Subjects: Amplification; Background noise; Boron nitride; broadband; Chemical bonds; Energy gap; Ferroelectric materials; Floating structures; Gain; Interlayers; localized field; Nanotechnology; Optoelectronics; photodetectors; Photoelectricity; Photometers; Photonics; Physical properties; Temperature gradients; Two dimensional materials; localized field; photodetectors; two-dimensional materials; broadband
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.201700894

Two‐dimensional (2D) materials have drawn tremendous attention in recent years. Being atomically thin, stacked with van der Waals force and free of surface chemical dangling bonds, 2D materials exhibit several distinct physical properties. To date, 2D materials include graphene, transition metal dichalcogenides (TMDS), black phosphorus, black P(1‐x)Asx, boron nitride (BN) and so forth. Owing to their various bandgaps, 2D materials have been utilized for photonics and optoelectronics. Photodetectors based on 2D materials with different structures and detection mechanisms have been established and present excellent performance. In this Review, localized field enhanced 2D material photodetectors (2DPDs) are introduced with sensitivity over the spectrum from ultraviolet, visible to infrared in the sight of the influence of device structure on photodetector performance instead of directly illustrating the detection mechanisms. Six types of localized fields are summarized. They are: ferroelectric field, photogating electric field, floating gate induced electrostatic field, interlayer built‐in field, localized optical field, and photo‐induced temperature gradient field, respectively. These localized fields are proved to effectively promote the detection ability of 2DPDs by suppressing background noise, enhancing optical absorption, improving electron‐hole separation efficiency, amplifying photoelectric gain and/or extending the detection range.
Localized fields are essential for two‐dimensional material photodetectors (2DPDs). They either suppress the dark current, promote the optical absorption, improve the electron‐hole seperation efficiency or extend the detection range. Fabricating different device structures can introduce various localized fields. The integration of multiple localized fields is promising for designing 2DPDs towards future practical applications.