High-Performance 2D MoS₂ Phototransistor for Photo Logic Gate and Image Sensor

Abstract

Two-dimensional (2D) MoS2 is a representative n-type transition-metal dichalcogenide (TMD) semiconductor that has great potential for future nanoscale electronic and optoelectronic applications. Here, we report a high-performance MoS2 phototransistor that exhibits a photoresponse in the 400–700 nm range with the maximum responsivity of over 1 × 104 A/W. As a more sophisticated optoelectronic application than a simple unit device, it is implemented in a photoinverter (NOT logic gate) connected to an external resistor, which clearly shows photoinduced static and dynamic characteristics. Furthermore, we demonstrate a prototype visible imager using the MoS2 photoinverter as imaging pixels as an excellent example of advanced developments in an optoelectronic system based on the 2D semiconductors.

Highly sensitive active pixel image sensor array driven by large-area bilayer MoS2 transistor circuitry

“…To obtain the colored image, each pixel of the image sensor array was measured with the turtle stencil under RGB light that differs from pixel to pixel, respectively. The light stencil projection method was inspired and developed from previous reports 30 , 64 . Lee et al 30 reported a single-pixel imager and the image scanning system with three different light sources (RGB).…”

A review of molybdenum disulfide (MoS2) based photodetectors: from ultra-broadband, self-powered to flexible devices

“…227 The phototransistor fabricated from multilayer MoS 2 using graphene source/drain electrodes showed a high photoresponsivity of 1 Â 10 4 A W À1 in the wavelength range of 470-600 nm. 228 Chen et al 229 developed n-n-type vdWHs using multilayer MoS 2 coated with a layer of nitrogen-doped graphene QDs (N-GQDs) to complement each other with their strong characteristics to improve the carrier mobility. In this hybrid structure, 230 by adding hydrogen gas during the CVD growth process, which resulted in centimeter-long monolayer MoS 2 continuous lms on graphene.…”

“…High photoresponsivities ranging from 10 3 A W À1 to 10 10 A W À1 have been observed for the graphene/MoS 2 hybrid structurebased photodetectors. 126,[226][227][228] Han et al 300 developed photodetectors using CVD-grown MoS 2 monolayers with both Au and graphene electrodes. MoS 2 photodetectors with graphene electrodes showed the current I on /I off ratio of 1 Â 10 5 and mobility of 0.48 cm 2 V À1 s À1 compared to 2 Â 10 3 and 0.1 cm 2 V À1 s À1 with gold electrodes.…”

Green‐Sensitive Phototransistor Based on Solution‐Processed 2D n‐Type Organic Single Crystal

“…One possible reason of this sublinear relationship between responsivity and light power is the reduction in the number of photogenerated carriers due to exciton recombination at high charge carrier density . Under weak light intensity of 3.5 µW cm −2 , the 2F‐4‐TFPTA 2D phototransistor exhibited responsivity of 3.6 × 10 3 A W −1 at the accumulation region, which is higher than that of a single‐crystal silicon phototransistor (≈3 × 10 2 A W −1 ) and comparable to that of conventional MoS 2 2D phototransistors (≈10 3 A W −1 ) . As expected from the absorption characteristics, the 2F‐4‐TFPTA 2D phototransistor is much more sensitive to green light than blue and red light.…”