Biphasic Liquid-Liquid Interface Limit Architecture of High-Quality Perovskite Single-Crystal Sheets for UV Photodetection

Liquid-Liquid Interfacial Nanoarchitectonics

Science in the small world has become a crucial key that has the potential to revolutionize materials technology. This trend is embodied in the postnanotechnology concept of nanoarchitectonics. The goal of nanoarchitectonics is to create bio-like functional structures, in which self-organized and hierarchical structures are working efficiently. Liquid-liquid interface like environments such as cell membrane surface are indispensable for the expression of biological functions through the accumulation and organization of functional materials. From this viewpoint, it is necessary to reconsider the liquid-liquid interface as a medium where nanoarchitectonics can play an active role. In this review, liquid-liquid interfacial nanoarchitectonics is classified by component materials such as organic, inorganic, carbon, and bio, and recent research examples are discussed. Examples discussed in this paper include molecular aggregates, supramolecular polymers, conductive polymers film, crystal-like capsules, block copolymer assemblies, covalent organic framework (COF) films, complex crystals, inorganic nanosheets, colloidosomes, fullerene assemblies, all-carbon π-conjugated graphite nanosheets, carbon nanoskins and fullerphene thin films at liquid-liquid interfaces. Furthermore, at the liquid-liquid interface using perfluorocarbons and aqueous phases, cell differentiation controls are discussed with the self-assembled structure of biomaterials. The significance of liquid-liquid interfacial nanoarchitectonics in the future development of materials will then be discussed.

Low-Temperature Vapor-Phase Anion-Exchange Strategy for Wide-Bandgap Double-Perovskite Cs2AgBiCl6 Films toward Weak Ultraviolet Light Imaging

Low-temperature synthesis of high-quality, high-stability, wide-bandgap perovskite films by solution methods is still challenging. Herein, large-scale wide-bandgap Cs₂AgBiCl₆ (CABC) double perovskite films are synthesized by a vapor-phase anion-exchange strategy. By dedicatedly designing an ultrathin TiO₂ modification layer between the substrate and double perovskites, high-quality heterojunctions with matched energy band alignment are formed, contributing to a remarkably enhanced ON/OFF ratio of 2.4 × 10⁴ (86 times) and a responsivity of 16 mA W^-1 (12 times). Additionally, the ultraviolet photodetectors (UV PDs) exhibit an excellent UV detection limit of 1.18 μW cm^-2 (20 nW), a broad linear dynamic range of 146 dB, and a high specific detectivity of 2.06 × 10¹¹ Jones, as well as long-term stability. Finally, we further demonstrate a weak UV imaging system using CABC UV PDs as imaging sensors. The system is capable of imaging weak UV signals as low as 2.94 μW cm^-2 (50 nW). Our results provide a feasible approach for low-temperature fabrication of wide-bandgap perovskite UV PDs and explore the promising application for weak UV detection and imaging.

All-Inorganic Perovskite Single Crystals for Optoelectronic Detection

Due to their many varieties of excellent optoelectric properties, perovskites have attracted large numbers of researchers in the past few years. For the hybrid perovskites, a long diffusion length, long carrier lifetime, and high μτ product are particularly noticeable. However, some disadvantages, including high toxicity and instability, restrict their further large-scale application. By contrast, all-inorganic perovskites not only have remarkable optoelectric properties but also feature high structure stability due to the lack of organic compositions. Benefiting from these, all-inorganic perovskites have been extensively explored and studied. Compared with the thin film type, all-inorganic perovskite single crystals (PSCs) with fewer grain boundaries and crystalline defects have better optoelectric properties. Nevertheless, it is important to note that only a few reports to date have presented a summary of all-inorganic PSCs. In this review, we firstly make a summary and propose a classification method according to the crystal structure. Then, based on the structure classification, we introduce several representative materials and focus on their corresponding growth methods. Finally, applications for detectors of all-inorganic PSCs are listed and summarized. At the end of the review, based on the current research situation and trends, some perspectives and advice are proposed.