Ultrahigh photo-responsivity and detectivity in multilayer InSe nanosheets phototransistors with broadband response

Abstract

We demonstrate the strategies and principles for the performance improvement of layered semiconductor based photodetectors using multilayer indium selenide (InSe) as the model materials. It is discovered that multiple reflection interference at the interfaces in phototransistor device leads to thickness-dependent photo-response, which provide a guideline to improve the performance of layered semiconductor based phototransistors. The responsivity and detectivity of InSe nanosheets phototransistor can be adjustable using applied gate voltage. Our InSe nanosheets phototransistor exhibits ultrahigh responsivity and detectivity. An ultrahigh external photo-responsivity of ~10 4 AW -1 can be achieved during broad spectra ranging from UV to near infrared wavelength from our InSe nanosheets photodetectors. The detectivity of multilayer InSe devices is ~ 10 12 ~ 10 13 Jones, which surpasses that of currentlyexploited InGaAs photodetectors (10 11 ~ 10 12 Jones). This research shows that multilayer InSe nanosheets are promising materials for high performance photodetectors.

Fast photoresponse and high detectivity in copper indium selenide (CuIn 7 Se 11 ) phototransistors

“…We found that the photoresponsivity reaches to its maximum value of ~ 51 AW -1 at an illumination intensity P eff = 63.3 nW when operating in the ON state (V g > 0 V). This value is significantly higher than the previously reported other III-VI group and other Se based 2D materials [14,15,21,22,[32][33][34][35][36][37][38][39][40].…”

“…Mudd et al [13] demonstrated that exfoliated InSe nano-sheets, show a crossover from a direct to an indirect band gap, when the flake thickness is reduced to a few nanometers. Similarly, studies also indicate that photo response in multilayer InSe nano-sheet based phototransistor increases with increasing number of layers and attains a maximum value, (in this [14] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 …”

Atomically thin InSe: A high mobility two-dimensional material

“…The most attracting properties are its lighter electron mass (m * =0.143 m 0 ) [6] and high electron mobility of 10 3 cm 2 V -1 s -1 . Recently, our and others studies reveal that thin-film InSe is a promising material for high performance electronic and optoelectronic devices [7][8][9][10]. The mobility of multilayer InSe FETs is up to 10 3 cm 2 V -1 s -1 due to suppressed carrier scattering from dielectric substrate [7].…”

“…The mobility of multilayer InSe FETs is up to 10 3 cm 2 V -1 s -1 due to suppressed carrier scattering from dielectric substrate [7]. Furthermore, few-layered InSe photodetector shows a high responsivity [9] and gatetunable behavior [10], making promising application in photodetection. However, the early studies still focus on multilayer or thin-film (10 nm) [7][8][9][10], atomically thin InSe is been ignored.…”

Material and Device Architecture Engineering Toward High Performance Two-Dimensional (2D) Photodetectors

“…Besides graphene-based heterojuctions, p-n junctions provide another platform to improve photoresponse [80]. As we know, p-n junctions are the basic building blocks of many optoelectronic devices, which have been utilized for rational control of their fundamental parameters, such as the bandgap, mobility and effective mass of charge carriers.…”