Visible‐infrared dual‐modal light harvesting is crucial for various optoelectronic devices, particularly for solar cells and photodetectors. For the first time, this study reports on large 25 cm3‐volume all‐inorganic perovskite CsPbBr3 single crystal (SC) with an emphasis on the observed visible‐infrared dual‐modal light harvesting and sensing as demonstrated by the high‐performance visible‐infrared dual‐modal photodetectors. First, ultralarge 25 cm3‐volume CsPbBr3 SC ingots with trapping state density as low as of 1 × 109 cm−3 have been achieved by a modified Bridgman growth method. The volume reported here is the largest CsPbX3 (X = Cl, Br, I) all‐inorganic perovskite system up to now, and the SC can be facilely cut into SC wafers with a diameter of 25 mm for various optoelectronic devices. Furthermore, these CsPbBr3 SCs exhibit a visible absorbance coefficient, a near‐infrared (IR) two‐phonon absorption coefficient, a carrier diffusion length, and a mobility as high as of 105 cm−1, 3.7 cm per Goeppert‐Mayer (GM), 10 µm and 2000 cm2 V−1 s−1, respectively. These merits match well to the requirements of high‐performance Vis‐IR dual‐modal light harvesting optoelectronic devices, which has been demonstrated by the CsPbBr3 SC photodetectors operated under the irradiation of both visible and IR light sources with light on/off ratio higher than 103. These results demonstrate the CsPbBr3 SCs with high visible‐infrared dual‐modal light harvesting capability and excellent electrical transporting properties have a huge potential in various optoelectronic devices, such as solar cells, photodetectors, and lasers.

Low cost and high conductivity make copper (Cu) nanowire (NW) electrodes an attractive material to construct flexible and stretchable electronic skins, displays, organic light-emitting diodes (OLEDs), solar cells, and electrochromic windows. However, the vulnerabilities that Cu NW electrodes have to oxidation, bending, and stretching still present great challenges. This work demonstrates a new Cu@Cu4Ni NW conductive elastomer composite with ultrahigh stability for the first time. Cu@Cu4Ni NWs, facilely synthesized through a one-pot method, have highly crystalline alloyed shells, clear and abrupt interfaces, lengths more than 50 μm, and smooth surfaces. These virtues provide the NW-elastomer composites with a low resistance of 62.4 ohm/sq at 80% transparency, which is even better than the commercial ITO/PET flexible electrodes. In addition, the fluctuation amplitude of resistance is within 2 ohm/sq within 30 days, meaning that at ΔR/R0 = 1, the actual lifetime is estimated to be more than 1200 days. Neither the conductivity nor the performances of OLED with elastomers as conductive circuits show evident degradation during 600 cycles of bending, stretching, and twisting tests. These high-performance and extremely stable NW elastomeric electrodes could endow great chances for transparent, flexible, stretchable, and wearable electronic and optoelectronic devices.

All-inorganic cesium lead halide perovskites have been emerging as the promising semiconductor materials for next-generation optoelectronics. However, the fundamental question of how the environmental atmosphere affects their photophysical properties, which is closely related to the practical applications, remains elusive. Here, we report the dynamic switching between radiative exciton recombination and non-radiative carrier trapping in CsPbBr 3 by controlling the atmospheric conditions. Specifically, we show that the photoluminescence (PL) intensity from the CsPbBr 3 crystals can be boosted by~60 times by changing the surrounding from vacuum to air. Based on the comprehensive optical characterization, nearambient pressure X-ray photoelectron spectroscopy (NAP-XPS) as well as density functional theory (DFT) calculations, we unravel that the physisorption of oxygen molecules, which repairs the trap states by passivating the PL-quenching bromine vacancies, is accountable for the enhanced PL in air. These results are helpful for better understanding the optical properties of all-inorganic perovskites.

Heterojunction manipulation has been deemed as a promising approach in exploring efficient photocatalysts for CO2 reduction. In this article, a novel step-scheme (S-scheme) photocatalyst of CsPbBr3 quantum dots/BiOBr nanosheets (CPB/BiOBr) was fabricated via a facile self-assembly process. The strong interaction, staggered energy band alignments, and much different Fermi levels between CsPbBr3 and BiOBr promised the formation of an S-scheme heterojunction. The resultant CPB/BiOBr heterojunction delivered remarkable photocatalytic performance in CO2 reduction, with an electron consumption rate of 72.3 μmol g–1 h–1, which was 4.1 and 5.7 times that of single CsPbBr3 and BiOBr, respectively. The superior photocatalytic performance originated from the impactful spatial separation of photoinduced electron–hole pairs, as well as the preservation of strongly reductive electrons for CO2 reduction. This work offers a rational strategy to design S-scheme heterojunctions based on lead halide perovskites, which are expected to have potential applications in the field of photocatalysis and solar energy utilization.

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Over the last 5 years, metal halide perovskites (MHPs) have emerged as promising photocatalysts for CO 2 reduction because of their extraodinary visible-lightharvesting capabilities and appropriate band structure. However, the CO 2 photoreduction activity of pristine MHPs is still unsatisfactory because of the phase instability, serious radiative recombination, and insufficient surface-active sites. This Perspective summarizes the strategies employed in recent studies for enhancing the photocatalytic CO 2 reduction performance of MHPs from the standpoint of structure engineering, which includes composition/dimension regulation, surface modification, and heterostructure construction. The relationship between the structure (composition, dimension, and shape) and photocatalytic performance is established, which is instructive for exploiting highly efficient perovskite-based photocatalysts in artificial photosynthesis applications. Further, some important challenges and future prospects of MHPs in this field are proposed and discussed.