High-quality infrared imaging with graphene photodetectors at room temperature

Fang

et al. 2018

Adv Funct Materials

Self Cite

1,055

872

2D material based photodetectors have attracted many research projects due to their unique structures and excellent electronic and optoelectronic properties. These 2D materials, including semimetallic graphene, semiconducting black phosphorus, transition metal dichalcogenides, insulating hexagonal boron nitride, and their various heterostructures, show a wide distribution in bandgap values. To date, hundreds of photodetectors based on 2D materials have been reported. Here, a review of photodetectors based on 2D materials covering the detection spectrum from ultraviolet to infrared is presented. First, a brief insight into the detection mechanisms of 2D material photodetectors as well as introducing the figure-of-merits which are key factors for a reasonable comparison between different photodetectors is provided. Then, the recent progress on 2D material based photodetectors is reviewed. Particularly, the excellent performances such as broadband spectrum detection, ultrahigh photoresponsivity and sensitivity, fast response speed and high bandwidth, polarization-sensitive detection are pointed out on the basis of the state-of-the-art 2D photodetectors. Initial applications based on 2D material photodetectors are mentioned. Finally, an outlook is delivered, the challenges and future directions are discussed, and general advice for designing and realizing novel high-performance photodetectors is given to provide a guideline for the future development of this fast-developing field.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/adfm.201803807. atomic layer, while these atomically thin layers are bonded together by weak van der Waals interactions along the third dimension perpendicular to the 2D plane. The weak interlayer interaction makes it possible to exfoliate bulk crystals into isolated thin 2D flakes and even a single atomically thin layer.A photodetector is a device that can convert a light signal into an electrical signal. High performance photodetectors play important roles in many fields of our daily life, including electro-optical displays, imaging, environment monitoring, optical communication, military, security checking and so forth. 2D materials, as one of most competitive materials for designing photodetectors, have been demonstrated with remarkable characteristics, including broad detection waveband covering the wavelengths from UV to terahertz frequencies (THz, 10 12 Hz), ultrahigh photoresponsivity, polarization sensitive photodetection, high-speed photoresponse, high spatially resolved imaging, etc. Thanks to the recently developed dry transfer technique, [1] various heterostructures based on 2D materials have been designed and fabricated with desirable band alignments. Photodetectors based on these heterostructures have exhibited enhanced performances like high photovoltaic external quantum efficiency up to 30% for graphene-WS 2 -graphene, [2] ultrahigh photoresponsivity up to ≈10 10 A W −1 for graphene-MoS 2 , [3] ultrahigh photogain ...

Section: Application Demonstration Based On 2d Materials Photodetectorsmentioning

confidence: 99%

“…(a) Left column top and middle: Reproduced with permission . Copyright 2016, American Chemical Society; Right three (a) right column reproduced with permission . Copyright 2016, Royal Society of Chemistry; (a) Left column bottom Reproduced with permission .…”

Section: Application Demonstration Based On 2d Materials Photodetectorsmentioning

confidence: 99%

Progress, Challenges, and Opportunities for 2D Material Based Photodetectors

Long

Fang

et al. 2018

Adv Funct Materials

Self Cite

1,055

872

“…For instance the breaking of inversion symmetry and strong valley‐spin coupling in TMDs cause them to exhibit valley‐dependent circular dichroism, and scaling the material from multilayer to monolayer can realize an indirect‐to‐direct bandgap transition . Therefore much effort has been devoted in seeking for various applications based on 2D materials, and the study of photodetectors based on 2D materials is a hot research field …”

Section: Introductionmentioning

confidence: 99%

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

Fang

et al. 2017

Small

Self Cite

254

199

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 As , 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.

“…Owing to its fascinating physical properties such as high electrical conductivity (10 8 S/m), and ultrahigh mobility (200000 cm −2 /V ∙ s at room temperature), graphene has great potential in fabricating thinner and faster response speed optoelectronic devices1617. However, it is undeniable that due to the relatively low absorbance of a single sheet of carbon atoms, graphene-based photodetectors normally suffer from relatively low responsivity.…”

mentioning

confidence: 99%

Broadband photodetector based on carbon nanotube thin film/single layer graphene Schottky junction

Zhang

et al. 2016

Sci Rep

106

In this study, we present a broadband nano-photodetector based on single-layer graphene (SLG)-carbon nanotube thin film (CNTF) Schottky junction. It was found that the as-fabricated device exhibited obvious sensitivity to a wide range of illumination, with peak sensitivity at 600 and 920 nm. In addition, the SLG-CNTF device had a fast response speed (τr = 68 μs, τf = 78 μs) and good reproducibility in a wide range of switching frequencies (50–5400 Hz). The on-off ratio, responsivity, and detectivity of the device were estimated to be 1 × 102, 209 mAW−1 and 4.87 × 1010 cm Hz1/2 W−1, respectively. What is more, other device parameters including linear performance θ and linear dynamic range (LDR) were calculated to be 0.99 and 58.8 dB, respectively, which were relatively better than other carbon nanotube based devices. The totality of the above study signifies that the present SLG-CNTF Schottky junction broadband nano-photodetector may have promising application in future nano-optoelectronic devices and systems.