Gate Tuning of High‐Performance InSe‐Based Photodetectors Using Graphene Electrodes

Abstract

In order to increase the response speed of the InSe-based photodetector with high photoresponsivity, Graphene is used as the transparent electrodes to modify the difference of the work function between the electrodes and the InSe. As expected, the response speed of InSe/graphene photodetectors is down to 120 μs, which is about 40 times faster than that of our InSe/metal device. And it can also be tuned by the back-gate voltage from 310 μs down to 100 μs. With high response speed, the photoresponsivity can reach as high as 60 AW -1 simultaneously. Meanwhile the InSe/graphene photodetectors possess a broad spectral range at 400-1000 nm. The design of 2D crystal/graphene electrical contacts could be important for high performance optoelectronic devices.

2D Metal Chalcogenides for IR Photodetection

“…In the family of 2D group IIIA metal chalcogenides, 2D In‐based chalcogenides including In 2 S 3 , In 2 Se 3 , In 2 Te 3 , and InSe, have shown great promise in IR photodetection applications. As shown in Figure a,b, our group has successfully synthesized ultrathin 2D β‐In 2 S 3 by improved space‐confined CVD method and has explored the broad detection up to 900 nm .…”

“…An optimal thickness of 30 nm InSe phototransistors has been fabricated on SiO 2 /Si substrate and demonstrated a high responsivity of up to 2.975 × 10 3 A W −1 accompanied by superior specific detectivity of 10 12 Jones and rapid switching time of 5–8 ms for 850 nm light . Moreover, Luo et al have improved the response time of InSe phototransistors to 120 µs utilizing graphene as the transmission electrode . The much improved response time is identified as the built‐in electric field formed between InSe and graphene as well as the high mobility of graphene …”

High‐Performance, Self‐Driven Photodetector Based on Graphene Sandwiched GaSe/WS2 Heterojunction

“…[5][6][7] Recently, the emergence of graphenelike semiconducting materials including black phosphorus, [8] transition metal dichalcogenides (TMDCs), [9,10] GaSe, [11,12] and InSe [13] have well remedied the zero-bandgap disadvantage and attracted tremendous attention. [5][6][7] Recently, the emergence of graphenelike semiconducting materials including black phosphorus, [8] transition metal dichalcogenides (TMDCs), [9,10] GaSe, [11,12] and InSe [13] have well remedied the zero-bandgap disadvantage and attracted tremendous attention.…”

Atomic-scale mechanisms of defect- and light-induced oxidation and degradation of InSe

“…Our predicted wide tunable Eg may account for the observed broadband photoresponse in layered InSe. 48,49 In principle, upon light illumination, the photo-excited electrons can be transferred to the adsorbed O2 molecules, thus affecting their adsorption and dissociation behaviors (refer to the schematic plot in Figure 1a). The effect of the photooxidation of InSe will be discussed shortly.…”