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The giant magnetoresistance effect in two-dimensional (2D) magnetic materials has sparked substantial interest in various fields; including sensing; data storage; electronics; and spintronics. Their unique 2D layered structures allow for the manifestation of distinctive physical properties and precise performance regulation under different conditions. In this review, we present an overview of this rapidly developing research area. Firstly, these 2D magnetic materials are catalogued according to magnetic coupling types. Then, several vital effects in 2D magnets are highlighted together with theoretical investigation, such as magnetic circular dichroism, magneto-optical Kerr effect, and anomalous Hall effect. After that, we forecast the potential applications of 2D magnetic materials for spintronic devices. Lastly, research advances in the attracting magnons, skyrmions and other spin textures in 2D magnets are discussed. [ABSTRACT FROM AUTHOR]

Strongly bound excitons in atomically thin transition metal dichalcogenides offer many opportunities to reveal the underlying physics of basic quasiparticles and many-body effects in the two-dimensional (2D) limit. Comprehensive reflection investigation on band-edge exciton transitions is essential to exploring wealthy light-matter interactions in the emerging 2D semiconductors, whereas angle-resolved reflection (ARR) characteristics of intralayer and interlayer excitons in 2D MoS2 layers remain unclear. Herein, we report ARR spectroscopic features of A, B, and interlayer excitons in monolayer (ML) and bilayer (BL) MoS2 on three kinds of photonic substrates, involving distinct exciton-photon interactions. In a BL MoS2 on a protected silver mirror, the interlayer exciton with one-third amplitude of A exciton appears at 0.05 eV above the A exciton energy, exhibiting an angle-insensitive energy dispersion. When ML and BL MoS2 lie on a SiO2-covered silicon, the broad trapped-photon mode weakly couples with the reflection bands of A and B excitons by the Fano resonance effect, causing the asymmetric lineshapes and the redshifted energies. After transferring MoS2 layers onto a one-dimensional photonic crystal, two high-lying branches of B-exciton polaritons are formed by the interactions between B excitons and Bragg photons, beyond the weak-coupling regime. This work provides ARR spectral benchmarks of A, B, and interlayer excitons in ML and BL MoS2, gaining insights into the interpretation of light-matter interactions in 2D semiconductors and the design of their devices for practical photonic applications. [ABSTRACT FROM AUTHOR]

Large-area, continuous monolayer WS2 exhibits great potential for future micro-nanodevice applications due to its special electrical properties and mechanical flexibility. In this work, the front opening quartz boat is used to increase the amount of sulfur (S) vapor under the sapphire substrate, which is critical for achieving large-area films during the chemical vapor deposition processes. COMSOL simulations reveal that the front opening quartz boat will significantly introduce gas distribute under the sapphire substrate. Moreover, the gas velocity and height of substrate away from the tube bottom will also affect the substrate temperature. By carefully optimizing the gas velocity, temperature, and height of substrate away from the tube bottom, a large-scale continues monolayered WS2 film was achieved. Field-effect transistor based on the as-grown monolayer WS2 showed a mobility of 3.76 cm2V−1 s−1 and ON/OFF ratio of 106. In addition, a flexible WS2/PEN strain sensor with a gauge factor of 306 was fabricated, showing great potential for applications in wearable biosensors, health monitoring, and human–computer interaction. [ABSTRACT FROM AUTHOR]

Blue perovskite light-emitting diodes (PeLEDs) have attracted enormous attention; however, their unsatisfactory device efficiency and spectral stability still remain great challenges. Unfavorable low-dimensional phase distribution and defects with deeper energy levels usually cause energy disorder, substantially limiting the device's performance. Here, an additive-interface optimization strategy is reported to tackle these issues, thus realizing efficient and spectrally stable blue PeLEDs. A new type of additive-formamidinium tetrafluorosuccinate (FATFSA) is introduced into the quasi-2D mixed halide perovskite accompanied by interface engineering, which effectively impedes the formation of undesired low-dimensional phases with various bandgaps throughout the entire film, thereby boosting energy transfer process for accelerating radiative recombination; this strategy also diminishes the halide vacancies especially chloride-related defects with deep energy level, thus reducing nonradiative energy loss for efficient radiative recombination. Benefitting from homogenized energy landscape throughout the entire perovskite emitting layer, PeLEDs with spectrally-stable blue emission (478 nm) and champion external quantum efficiency (EQE) of 21.9% are realized, which represents a record value among this type of PeLEDs in the pure blue region., (© 2024 Wiley‐VCH GmbH.)