Photoresponse of Graphene-Gated Graphene-GaSe Heterojunction Devices

Abstract

Because of their extraordinary physical properties, low-dimensional materials including graphene and gallium selenide (GaSe) are promising for future electronic and optoelectronic applications, particularly in transparent-flexible photodetectors. Currently, the photodetectors working at the near-infrared spectral range are highly indispensable in optical communications. However, the current photodetector architectures are typically complex, and it is normally difficult to control the architecture parameters. Here, we report graphene–GaSe heterojunction-based field-effect transistors with broadband photodetection from 730–1550 nm. Chemical-vapor-deposited graphene was employed as transparent gate and contact electrodes with tunable resistance, which enables effective photocurrent generation in the heterojunctions. The photoresponsivity was shown from 10 to 0.05 mA/W in the near-infrared region under the gate control. To understand behavior of the transistor, we analyzed the results via simulation performed using a model for the gate-tunable graphene–semiconductor heterojunction where possible Fermi level pinning effect is considered.

Solution‐Processed GaSe Nanoflake‐Based Films for Photoelectrochemical Water Splitting and Photoelectrochemical‐Type Photodetectors

“…Due to its structure, GaSe shows fascinating optoelectronic properties, including photoresponse in ultraviolet–visible (UV–vis) spectral range (from 1.8 to 5 eV), nonlinear optical behavior, and a distinctive spin physics (e.g., spin‐orbit coupling effects and generation/retention of spin polarization under nonresonant optical pumping). For the aforementioned properties, GaSe has been proposed for photodetectors with high responsivity (e.g., up to values > 1000 A W −1 at light intensity ≤ 0.1 mW cm −2 , in heterojunction with graphene), nonlinear frequency generation (e.g., second and third harmonic and ultrabroadband radiation generation), spin polarization control (e.g., spintronic logic devices), light‐emitting devices, optical microcavities, and saturable absorbers . Moreover, the number of layers and strain engineering strongly affect the GaSe optoelectronic properties, which can be on‐demand tailored to fulfill the requirements of the final applications .…”

High photoresponsivity and broadband photodetection with a band-engineered WSe2/SnSe2 heterostructure

“…van der Waals (vdW) heterojunctions, formed by stacking different individual 2D layered materials, can offer a new dimension in breaking the abovementioned intrinsic bandgap barrier. [21][22][23][24][25][26][27][28][29][30][31] In general, three types of band alignments can be categorized when different 2D materials are stacked together, 32 including type-I, 33 type-II, [34][35][36][37][38] and type-III [39][40][41][42][43] band alignments. Thus far, most of the reported vdW heterostructure photodetectors are based on the type-II band alignment to utilize the excellent electron-hole pair separation ability in heterostructures.…”

Two‐Dimensional Metal Chalcogenide Heterostructures: Designed Growth and Emerging Novel Applications

“…[ 190 ] Recently, of particular interest is 2DMCHs‐based IR photodetectors because 2DMCHs can't produce the traps which limit the performance of photodetectors related to the lattice mismatch and their atomically thin thickness can reduce noise resulting from generation‐recombination. [ 38,52,90,93,129,130,190–211 ] Most notably, the thickness‐dependent properties of 2DMCHs enable to regulate the performance of IR photodetectors. Javey et al.…”