Surface-enhanced Raman spectroscopy chips based on two-dimensional materials beyond graphene

Surface-enhanced Raman spectroscopy(SERS) based on two-dimensional(2 D) materials has attracted great attention over the past decade. Compared with metallic materials, which enhance Raman signals via the surface plasmon effect, 2 D materials integrated on silicon substrates are ideal for use in the fabrication of plasmon-free SERS chips, with the advantages of outstanding fluorescence quenching capability, excellent biomolecular compatibility, tunable Fermi levels, and potentially lowcost material preparation. Moreover, recent studies have shown that the limits of detection of 2 D-material-based SERS may be comparable with those of metallic substrates, which has aroused significant research interest. In this review, we comprehensively summarize the advances in SERS chips based on 2 D materials. As several excellent reviews of graphene-enhanced Raman spectroscopy have been published in the past decade, here, we focus only on 2 D materials beyond graphene, i.e., transition metal dichalcogenides, black phosphorus, hexagonal boron nitride, 2 D titanium carbide or nitride, and their heterostructures. We hope that this paper can serve as a useful reference for researchers specializing in 2 D materials, spectroscopy, and diverse applications related to chemical and biological sensing.

Solution processable transition metal dichalcogenides-based hybrids for photodetection

Transition metal dichalcogenides(TMDs), as one of the most promising two-dimensional(2D) materials, have attracted considerable attention for use in photodetection applications over the past few years due to their distinct properties, such as atomic-scale thickness, tunable direct bandgaps, and decent carrier mobilities at room temperature. Compared with pure 2D TMDs, the construction of hybrids consisting of TMDs and other low-dimensional materials can further improve the performance of photodetectors including their spectral range, responsivity and detectivity, which significantly boosts interest in the development of TMDs-based photodetectors. On the other hand, solution-phase synthesis methods provide a facile strategy for the scalable production of TMD hybrids, opening an exciting avenue to develop low-cost devices. In this review, we summarize the material synthesis, characterizations, and photodetection applications of the solution processable TMDs-based hybrids, as well as provide insights into their prospects.

High-entropy perovskite oxides:An emergent type of photochromic oxides with fast response for handwriting display

Stimulus-responsive materials are fundamental to the broad and ever-growing field of intelligence research,which bridge intelligent systems with the Internet of Things(loT)in future lifestyles.Among these materials,writable materials have received great interest;however,carbonization and irreversible writing processes are generally inevitable for extensively investigated organic compounds.Photochromism is a potential mode of composing information.Nevertheless,inorganic materials usually exhibit weak photochromic effects.Here,a novel strategy of designing high-entropy perovskite(HEP)oxides is put forward to develop a new inorganic photochromic system with satisfying performance.A series of HEP oxides are synthesized for the first time.Benefiting from excellent photochromic features,real-time information encoding was achieved.The mechanism-related photochromism is also discussed.Distinct from the previous works,it is believed that the present photochromic-based HEP oxides provide a new and manyfold research space for the future development of conventional writable materials and the disclosing of unprecedented properties and phenomena.