Halide perovskite quantum dots (QDs), primarily regarded as optoelectronic materials for LED and photovoltaic devices, have not been applied for photochemical conversion (e.g., water splitting or CO reduction) applications because of their insufficient stability in the presence of moisture or polar solvents. Herein, we report the use of CsPbBr QDs as novel photocatalysts to convert CO into solar fuels in nonaqueous media. Under AM 1.5G simulated illumination, the CsPbBr QDs steadily generated and injected electrons into CO, catalyzing CO reduction at a rate of 23.7 μmol/g h with a selectivity over 99.3%. Additionally, through the construction of a CsPbBr QD/graphene oxide (CsPbBr QD/GO) composite, the rate of electron consumption increased 25.5% because of improved electron extraction and transport. This study is anticipated to provide new opportunities to utilize halide perovskite QD materials in photocatalytic applications.

Lead halide perovskite nanocrystals (NCs) have demonstrated great potential as appealing candidates for advanced optoelectronic applications. However, the toxicity of lead and the intrinsic instability toward moisture hinder their mass production and commercialization. Herein, to solve such thorny problems, novel lead-free Cs AgBiBr double perovskite NCs fabricated via a simple hot-injection method are reported, which exhibit impressive stability in moisture, light, and temperature. Such materials are then applied into photocatalytic CO reduction, achieving a total electron consumption of 105 µmol g under AM 1.5G illumination for 6 h. This study offers a reliable avenue for Cs AgBiBr perovskite nanocrystals preparation, which holds a great potential in the further photochemical applications.

Organometal trihalide perovskites have been attracting intense attention due to their enthralling optoelectric characteristics. Thus far, most applications focus on polycrystalline perovskite, which however, is overshadowed by single crystal perovskite with superior properties such as low trap density, high mobility, and long carrier diffusion length. In spite of the inherent advantages and significant optoelectronic applications in solar cells and photodetectors, the fabrication of large-area laminar perovskite single crystals is challenging. In this report, an ingenious space-limited inverse temperature crystallization method is first demonstrated to the in situ synthesis of 120 cm large-area CH NH PbBr crystal film on fluorine-doped tin oxide (FTO) glass. Such CH NH PbBr perovskite crystal film is successfully applied to narrowband photodetectors, which enables a broad linear response range of 10 -10 mW cm , 3 dB cutoff frequency (f ) of ≈110 kHz, and high narrow response under low bias -1 V.

Nowadays, obtaining a thin and large-area perovskite single-crystal (SC) is still challenging. Herein, we report a novel strategy to prepare a laminar MAPbBr SC with a controllable thickness of 16 μm and a size of 6 × 8 mm. Additionally, the SC solar cell achieves an intriguing efficiency of 7.11% with an impressive stability, maintaining 93% initial PCE after aging for 1000 h.

Dimension engineering is developed to form 2D BA2CsPb2I7 by introducing a bulky ammonium cation, which exhibits superior structural and compositional stability.