MoS₂/HfO₂/Silicon‐On‐Insulator Dual‐Photogating Transistor with Ambipolar Photoresponsivity for High‐Resolution Light Wavelength Detection

Abstract

Photogating detectors based on 2D materials attract significant research interests. However, most of these photodetectors are only sensitive to the incident intensities and lack the ability to distinguish different wavelengths. Color imaging based on these detectors usually requires additional optical filter arrays to collect red, green, and blue (RGB) colors in different photodetectors to restore the true color of one pixel. In this study, an MoS2/HfO2/silicon‐on‐insulator field effect phototransistor with wavelength distinguishing ability is presented, where the photogating effect can be simultaneously formed in the top MoS2 gate and bottom Si substrate gate. These two individual photogating effects can reduce and increase the read current in the middle 12 nm Si channel, respectively. Thus, by tuning the applied voltages on these two gates, the device can be used to obtain tunable ambipolar photoresponsivity from +7000 A W−1 (Si bottom gate dominated) to 0 A W−1 (balanced), and finally to −8000 A W−1 (MoS2 gate dominated). In addition, the experimental results show that the corresponding top gate voltage to the zero responsivity (0 A W−1) point can be positively shifted by the increasing of incident wavelength with high resolution up to 2 nm and is insensitive to the incident intensity.

A Review on the Recent Progress of Silicon‐on‐Insulator‐Based Photodetectors

“…Thus, novel photodetectors with simplified data processing and enhanced detection sensitivity under very weak illumination condition are needed. Deng et al, [ 63 ] invented a novel MoS 2 /HfO 2 /SOI phototransistor with a wavelength detection resolution of 2 nm and excellent suppression of intensity response.…”

“…d) The relationship between V tg 0 and the light intensity. Adapted with permission [63]. Copyright 2019, Wiley-VCH.…”

Ternary 2D Layered Material FePSe3 and Near‐Infrared Photodetector

“…[ 1 ] In particular, the strong coupling between 2DLM layers and incident illumination greatly improves the optical absorption efficiency in photodetection, [ 2 ] the approximate ballistic scattering in a single atomic film dramatically enhances the carrier mobility in the active device area, [ 3,4 ] and the strict restriction of carrier distribution in the 2DLM channel facilitates the field‐effect and gate modulation by electric, ferroelectric, magnetic and other technologies. [ 5–7 ] Moreover, no dangling bonds exist on the surface so that novel structures can be fabricated by stacking 2DLMs with van der Waals interaction. [ 8–10 ] Graphene and black phosphorus (BP) are the most famous typical 2D material pioneers.…”

Light-modulated vertical heterojunction phototransistors with distinct logical photocurrents

“…However, the inferior light absorption of single atomic layer graphene limits the phototransistor performance 10 . 2D/semiconductor heterojunctions are expected to break the electron-hole occupation symmetry, giving rise to the generation of photocurrents, including in quantum dot-enhanced structures 11,12 , stacked 2D heterojunction structures [13][14][15][16][17] , 2D planar structures 18,19 , dual photogating phototransistors 20 , waveguide-integrated enhanced structures 21,22 , bilayer-enhanced structures 23,24 , and even nanographite structures 25,26 . In particular, some typical 2D localized field methods incorporating 2D, organic, perovskite, and Dirac materials were subsequently proposed to realize high-performance phototransistors 23,24,[27][28][29][30][31][32][33] .…”