P‐GaSe/N‐MoS₂ Vertical Heterostructures Synthesized by van der Waals Epitaxy for Photoresponse Modulation

Abstract

The important role of p-n junction in modulation of the optoelectronic properties of semiconductors is widely cognized. In this work, for the first time the synthesis of p-GaSe/n-MoS heterostructures via van der Waals expitaxial growth is reported, although a considerable lattice mismatching of ≈18% exists. According to the simulation, a significant type II p-n junction barrier located at the interface is expected to be formed, which can modulate optoelectronic properties of MoS effectively. It is intriguing to reveal that the presence of GaSe can result in obvious Raman and photoluminescence (PL) shift of MoS compared to that of pristine one, more interestingly, for PL peak shift, the effect of GaSe-induced tensile strain on MoS has overcome the p-doping effect of GaSe, evidencing the strong interlayer coupling between GaSe and MoS . As a result, the photoresponse rate of heterostructures is improved by almost three orders of magnitude compared with that of pristine MoS .

2D In2S3 Nanoflake Coupled with Graphene toward High‐Sensitivity and Fast‐Response Bulk‐Silicon Schottky Photodetector

“…In addition, Raman spectroscopy is sensitive to interlayer coupling in the heterostructures . The A 1g mode of In 2 S 3 exhibits obvious red‐shift at the heterostructure, in contrast to the E 1g mode exhibiting a weak blue‐shift, suggesting electron‐doping of In 2 S 3 at the heterostructure …”

“…[10] The A 1g mode of In 2 S 3 exhibits obvious red-shift at the heterostructure, in contrast to the E 1g mode exhibiting a weak blue-shift, suggesting electron-doping of In 2 S 3 at the heterostructure. [22] In order to reveal the interlayer electron-hole separation behavior at the In 2 S 3 /graphene/Si interface, photoluminescence (PL) measurements were performed. As shown in Figure 2a, In 2 S 3 on the SiO 2 substrate presents an obvious PL peak at 650 nm, which corresponds to a bandgap of 1.91 eV.…”

Strategies for Air‐Stable and Tunable Monolayer MoS2‐Based Hybrid Photodetectors with High Performance by Regulating the Fully Inorganic Trihalide Perovskite Nanocrystals

“…However, the atomically thin nature of 2D MoS 2 crystals results in an extremely inefficient light‐trapping ability, which is a fatal flaw for photodetector devices. The practical application of MoS 2 ‐based photodetectors is also hindered by severely limited photoresponse and detecting capability, slow response rate, etc. As a result, many efforts have been made to optimize the performance of atomic‐layer MoS 2 ‐based optoelectronics …”

“…Many studies have shown that the use of hybrid photodetectors (HPs) can mitigate the disadvantages of atomically thin MoS 2 crystals. Under the synergistic effect of multimaterials, hybrid MoS 2 ‐based devices show improved response rates and responsivities . For example, the photoresponse rate of a MoS 2 ‐based device increased by almost three orders of magnitude by constructing the heterojunctions with GaSe flakes, and a greatly increased responsivity (10 6 A W −1 ) was achieved in a TiO 2 ‐encapsulated MoS 2 transistor–modified by HgTe quantum dots .…”

“…Under the synergistic effect of multimaterials, hybrid MoS 2 ‐based devices show improved response rates and responsivities . For example, the photoresponse rate of a MoS 2 ‐based device increased by almost three orders of magnitude by constructing the heterojunctions with GaSe flakes, and a greatly increased responsivity (10 6 A W −1 ) was achieved in a TiO 2 ‐encapsulated MoS 2 transistor–modified by HgTe quantum dots . Therefore, a heterojunction structure improves the performance of MoS 2 ‐based photodetectors, and the successful integration of dissimilar materials may pave the way toward successful high‐performance hybrid optoelectronic devices.…”