β‐In2S3 is a natural defective III–VI semiconductor attracting considerable interests but lack of efficient method for its 2D form fabrication. Here, for the first time, this paper reports controlled synthesis of ultrathin 2D β‐In2S3 flakes via a facile space‐confined chemical vapor deposition method. The natural defects in β‐In2S3 crystals, clearly revealed by optical spectra and optoelectronic measurement, strongly modulate the (opto)‐electronic of as‐fabricated β‐In2S3 and render it a broad detection range from visible to near‐infrared. Particularly, the as‐fabricated β‐In2S3 photodetector shows a high photoresponsivity of 137 A W−1, a high external quantum efficiency of 3.78 × 104%, and a detectivity of 4.74 × 1010 Jones, accompanied with a fast rise and decay time of 6 and 8 ms, respectively. In addition, an interesting linear response to the testing power intensities range is observed, which can also be understood by the presence of natural defects. The unique defective structure and intrinsic optical properties of β‐In2S3, together with its controllable growth, endow it with great potential for future applications in electronics and optoelectronics.

Infrared light detection is generally limited by the intrinsic bandgap of semiconductors, which suppresses the freedom in infrared light photodetector design and hinders the development of high‐performance infrared light photodetector. In this work, for the first time infrared light (1030 nm) photodetectors are fabricated based on WS2/MoS2 heterostructures. Individual WS2 and MoS2 have no response to infrared light. The origin of infrared light response for WS2/MoS2 comes from the strong interlayer coupling which shrinks the energy interval in the heterojunction area thus rendering heterostructures longer wavelength detection ability compared to individual components. Considering the low light absorption due to indirect bandgap essence of few layers WS2/MoS2 heterostructures, its infrared responsivity is further enhanced with at most ≈25 times but the fast response rate is maintained via surface plasmon resonance (SPR). Such an interlayer coupling induced infrared light response and surface plasmon resonance enhancement strategy paves the way for high‐performance infrared light photodetection of infinite freedom in design.

Two dimensional (2D) magnetic materials display enormous application potential in spintronic fields. However, most of currently reported magnetic materials are van der Waals layered structure that is easy to be isolated via exfoliation method. By contrast, the studies on non-van der Waals ultrathin magnetic materials are rare, largely due to the difficulty in fabrication. Rhombohedral Cr 2 S 3 , an intensively studied antiferromagnetic transition metal chalcogenide with Neel temperature of ≈120 K, has a typical non-van der Waals structure. Restricted by the strong covalent bonding in all the three dimensions of non-van der Waals structure, the synthesis of ultrathin Cr 2 S 3 single crystals is still a challenge that is not achieved yet. Besides, the study on the Raman modes of rhombohedral Cr 2 S 3 is also absent. Herein, by employing space-confined chemical vapor deposition strategy, ultrathin rhombohedral Cr 2 S 3 single crystals with a thickness down to ≈2.5 nm for the first time are successfully grown. Moreover, a systematically investigation is also conducted on the Raman vibrations of ultrathin rhombohedral Cr 2 S 3 . With the aid of angle-resolved polarized Raman technique, the Raman modes of rhombohedral Cr 2 S 3 for the first time based on crystal symmetry and Raman selection rules are rationally assigned.

Transition metal dichalcogenides (TMDs) consist of dozens of ultrathin layered materials that have significantly different properties due to their varied phases, which determine the properties and application range of TMDs. Interestingly, a controllable phase transition in TMDs is achieved extensively with the use of several methods. Thus, phase control is a promising way to fully exploit the potential of TMDs. This review introduces the recent rapid development of the study of the TMD phase control, starting from the basic conception of the phase and phase transition in TMDs to the strategies for obtaining phase control. The different strategies are roughly classified into several types based on their characteristics: doping, synthesis method, strain, thermal method, and interlayer coupling. Finally, an evaluation on the prospect of the emergent strategies is provided.

GaTe is an important III-VI semiconductor with direct bandgap; thus, it holds great potential in the field of optoelectronics. Although it is known that GaTe can exist both in monoclinic and hexagonal phases, current studies are still exclusively restricted to the monoclinic phase of two dimensional (2D) GaTe owing to the difficulty in the fabrication of 2D hexagonal GaTe. Both monoclinic and hexagonal GaTe are demonstrated in this work, which can be selectively synthesized via a physical vapor deposition method, under precisely controlled growth temperatures. The pristine Raman and non-linear optical properties of hexagonal GaTe has been systematically explored for the first time; moreover, a novel selected-area phase transition from hexagonal to monoclinic of GeTe has been achieved via fs-laser irradiation. This work may pave the way for widely use of 2D GaTe in various fields in future.a strategy for selected-area phase transition from h-GaTe to m-GaTe, which may pave the way for wide applications of GaTe in future.