Hongbin Xiao

Perovskite solar cells (PSCs) employing three‐dimensional/two‐dimensional (3D/2D) heterostructures achieve high efficiencies but suffer from limited operational stability. Combining high‐throughput experiments with first‐principles simulations, we unveil that 2D perovskites are intrinsically susceptible to thermal degradation due to the deprotonation of spacer cations and subsequent escape of hydrogen iodide. Through artificial intelligence analysis of 278 distinct perovskites, we identify the surface electrostatic properties and molecular polarity of spacer cations as the key descriptors governing thermal resilience. Finally, we discover a bi‐cationic 2D perovskite that integrates low‐polarity phenylethylammonium with high‐polarity pentafluorophenylethylammonium (5FBA), synergistically resolving phase segregation and thermal degradation beyond what either cation can achieve alone. The bi‐cationic 3D/2D perovskite film stack shows suppressed ion migration owing to the robust interaction between 5FBA and 3D perovskite. Consequently, the resulting PSCs retain over 92% of their initial efficiency after 1500 h of thermal aging at 85°C and over 90% after 2000 h of continuous operation under 1‐Sun illumination.

The small size and large trap density have seriously hindered the application of cesium copper iodine single crystals (SCs). Herein, we propose a strategy for synthesizing high-quality and large-sized CsCu2I3 SCs by gradient crystallization. The as-synthesized CsCu2I3 SCs exhibit a large length of 1.7 cm with a low trap density of 4.17 × 109 cm−3. Moreover, such CsCu2I3 SCs show excellent photoelectric response to ultraviolet (UV) irradiation, owing to their high absorption coefficient, large Stokes shift, and one-dimensional electronic structure. The measured responsivity and detectivity of the CsCu2I3 SC-based photodetectors reach the maxima of 24.58 A/W and 1.02 × 1013 Jones, respectively, under 365 nm light irradiation. Due to the outstanding UV detection performance, such photodetectors are also utilized for achieving direct UV imaging with high resolutions.

According to dynamic behaviors of BF₄-based ionic liquids (ILs) at the SnO₂/FAPbI₃ interface, the BMIMBF₄ IL not only eliminates the density of states in SnO₂ but also increases the ion migration energy barrier in FAPbI₃.

Lead‐free metal halides are considered a new generation of optoelectronic materials due to their low toxicity, superior optoelectronic properties, ease of synthesis, structural diversity, and low cost. In particular, Mn²⁺‐based metal halides have earned intensive attention owing to their high emission quantum efficiency, rich physical properties (e.g., triboluminescence and stimuli‐responsivity), low cost, and toxicity. Due to the different coordination environments of Mn ions, Mn²⁺‐based metal halides can exhibit green, red, and near‐infrared emissions. This review summarizes the recent progress of Mn²⁺‐based metal halides in synthesis methods, emission mechanisms, photophysical properties, and representative applications in X‐ray scintillations, white light‐emitting diodes, optical anti‐counterfeiting technologies, and fluorescent sensors. Finally, the challenges and potential research directions toward developing Mn²⁺‐based metal halides are also predicted.

The emission of harmful gases has seriously exceeded relative standards with the rapid development of modern industry, which has shown various negative impacts on human health and the natural environment. Recently, metal–organic frameworks (MOFs)-based materials have been widely used as chemiresistive gas sensing materials for the sensitive detection and monitoring of harmful gases such as NO_x, H₂S, and many volatile organic compounds (VOCs). In particular, the derivatives of MOFs, which are usually semiconducting metal oxides and oxide–carbon composites, hold great potential to prompt the surface reactions with analytes and thus output amplified resistance changing signals of the chemiresistors, due to their high specific surface areas, versatile structural tunability, diversified surface architectures, as well as their superior selectivity. In this review, we introduce the recent progress in applying sophisticated MOFs-derived materials for chemiresistive gas sensors, with specific emphasis placed on the synthesis and structural regulation of the MOF derivatives, and the promoted surface reaction mechanisms between MOF derivatives and gas analytes. Furthermore, the practical application of MOF derivatives for chemiresistive sensing of NO₂, H₂S, and typical VOCs (e.g., acetone and ethanol) has been discussed in detail.

One-dimensional K₂CuBr₃ single crystals are demonstrated for visible light communication with a high data transmission rate of 248 Mbps, which is more than 33-fold the −3 dB bandwidth.

Incorporating metallic nanostructures into a cesium lead halide [CsPbX₃ (X = Cl, Br, I)] perovskite system has attracted considerable attention for improving the performance of amplified spontaneous emission (ASE) and lasing. However, the ASE/lasing threshold is normally quite high since the photophysical properties of pristine CsPbX₃ quantum dots (QDs) are limited and the traditionally utilized metal nanoparticles suffer from a weak localized surface plasmon resonance within a narrow spectral range. Herein, a configuration of a silica coated CsPbBr₃ QDs (CsPbBr₃@SiO₂ QDs) film incorporated with the deposition of gold nanorods (AuNRs) underneath has been proposed for high-performance ASE. In this configuration, SiO₂ coating not only serves as an insulation layer to avoid the large Ohmic loss between CsPbBr₃ and Au but also contributes to improved photoluminescence quantum yield and stability against water, heat, and ultraviolet light compared to the counterparts of pristine CsPbBr₃ QDs. As a result, the fabricated CsPbBr₃@SiO₂-AuNRs hybrid film yields a low-threshold ASE (23.6 μJ/cm²) with excellent photostability owing to efficient exciton–plasmon coupling effect, which is only 23% of the pristine CsPbBr₃ QDs film (102 μJ/cm²). The demonstration of metallic NRs coupled perovskite QDs not only provides a strategy for realizing strong light–matter interactions but also paves the way for improving the performance of perovskite-based optoelectronic devices.

The periodic engineering of AgS ₆ and BiS ₆ octahedrons is demonstrated. The modulated AgBiS ₂ achieves a spectroscopic limited maximum efficiency as high as 29.7% with an ultrathin thickness of 100 nm.