Two-dimensional GaSe/MoSe ₂ misfit bilayer heterojunctions by van der Waals epitaxy

Abstract

Synthesized two-dimensional GaSe/MoSe2 misfit heterostructures form p-n junctions with a gate-tunable photovoltaic response.

Toward High‐Performance Photodetectors Based on 2D Materials: Strategy on Methods

“…Li et al achieved a GaSe/MoSe 2 heterojunction through a two‐step growth process and fabricated a photodetector by patterning a source–drain contact on a monolayer MoSe 2 flake partially covered by monolayer GaSe domains, as shown in Figure c. Under white‐light illumination, the device exhibited a stable photoresponse with an ON/OFF ratio up to 215 and a reproducible photoresponsivity of ≈30 mA W −1 . Besides direct CVD growth vertical heterojunctions, in‐plane heterojunctions have also been investigated by Duan et al, as shown in Figure d.…”

Curvature-dependent flexible light emission from layered gallium selenide crystals

“…2,3 Because the interlayers of GaSe crystal are connected via van der Waals bonds, it can be exfoliated to few layer or even monolayers for further device application. 4 It means that GaSe could be considered as a exible material even while it is exfoliated from thick to thin multilayers. For light-emitting capability, unlike MoSe 2 which has only enhanced photoluminescence (PL) efficiency as a monolayer, the PL intensity of monolayer GaSe vanishes, and increases with the layer thickness increasing to multilayer or bulk form.…”

“…4,13 Among those methods, strain engineering is more attractive and applicable when a exible optoelectronics device is under normally-operated condition. Our previous research has found that the mechanical bending would also enhance the light intensity of photoluminescence peak of 2D InSe layered semiconductor.…”

2D Photovoltaic Devices: Progress and Prospects

“…Furthermore, by sandwiching graphene (g) in an atomically thin MoS 2 –WSe 2 p–n junction (forming a p–g–n heterostructure), the spectral range can be broadened to the infrared regime due to the gapless nature of the graphene . In addition to the most studied MoS 2 /WSe 2 vdW heterojunction, vertical heterostructures based on other 2D crystals, such as BP/MoS 2 , WSe 2 /MoSe 2 , α‐MoTe 2 /MoS 2 , SnS 2 /MoS 2 , GaTe/MoS 2 , GaSe/MoSe 2 , ReS 2 /ReSe 2 , MoS 2 /Bi 2 Te 3 , and MoS 2 /WS 2 /WSe 2 , have also been explored for their potential in photovoltaics. Particularly, TMDCs can be assembled with organic materials for efficient 2D‐based solar cells.…”