Tailoring thermal radiation using low‐infrared‐emissivity materials has drawn significant attention for diverse applications, such as passive radiative heating and thermal camouflage. However, the previously reported low‐infrared‐emissivity materials have the bottleneck of lacking independent control over visible optical properties. Here, a novel visibly transparent and infrared reflective (VTIR) coating by exploiting a nano‐mesh patterning strategy with an oxide–metal–oxide tri‐layer structure is reported. The VTIR coating shows simultaneously high transmittance in the visible region (>80% at 550 nm) and low emissivity in the mid‐infrared region (< 20% in 7–14 µm). The VTIR coating not only achieves a radiative heating effect of 6.6 °C for indoor conditions but also enables a synergetic effect with photothermal materials to keep human body warm at freezing temperatures for outdoor conditions, which is 10–15 °C warmer than normal cotton and Mylar film. Moreover, it demonstrates an excellent thermal camouflage effect at various temperatures (34–250 °C) and good compatibility with visible camouflage on the same object, making it ideal for both daytime and nighttime cloaking. With its unique and versatile spectral features, this novel VTIR design has great potential to make a significant impact on personal heat management and counter‐surveillance applications.

Organic–inorganic halide perovskites have been widely investigated for the fabrication of photodetectors because of their excellent optoelectronic properties. However, the toxicity of Pb‐based perovskites and the lack of manufacturing technology in air limits the commercialization of perovskite‐based photodetectors. Tin halide perovskite (THP) is a promising candidate to replace Pb‐based perovskites due to its low toxicity and potential commercialization. However, THP suffers poor stability in air because Sn2+ is easily oxidized to Sn4+. This “self‐doping” effect not only degrades device performance rapidly, but also makes it difficult to fabricate THP‐based devices in air. Here, Pb‐free Sn‐based 2D perovskite PEA2SnI4 films with tin fluoride (SnF2) additive are prepared in air using a nitrogen quenching hot casting method. The photodetectors with an optimal SnF2 concentration of 20% exhibit a fast response speed of 0.56 ms and an excellent specific detectivity of 6.32 × 1013 Jones, the best combination of THP‐based photodetectors reported hitherto. The SnF2 additive is found to suppress the formation of Sn vacancies and improve the crystallinity of PEA2SnI4 films. The work provides an air‐processing technology of Pb‐free perovskite, which is easy to commercialize, and SnF2 additive engineering offering an effective way to demonstrate high performance photodetectors and image recognition applications.

Perovskite has been actively studied for optoelectronic applications, such as photodetectors and light-emitting diodes (LEDs), because of its excellent optoelectronic properties. However, ionic bonds of the perovskite structure are vulnerable to chemicals, which makes perovskite incompatible with photolithography processes that use polar solvents. Such incompatibility with photolithography hinders perovskite patterning and device integration. Here, an all-solution based cesium lead halide perovskite (Cs x Pb y Br z ) patterning method is introduced in which PbBr 2 is patterned and then synthesized into Cs x Pb y Br z . Each step of the top-down patterning process (e.g., developing, etching, and rinsing) is designed to be compatible with existing photolithography equipment. Structural, chemical, and optical analyses show that the PbBr 2 pattern of (10 µm) 2 squares is successfully transformed into CsPbBr 3 and Cs 4 PbBr 6 with excellent absorption and emission properties. Highresolution photoconductor arrays and luminescent pattern arrays are fabricated with CsPbBr 3 and Cs 4 PbBr 6 on various substrates, including flexible plastic films, to demonstrate their potential applications in image sensors or displays. The research provides a fundamental understanding of the properties and growth of perovskite and promotes technological advancement by preventing degradation during the photolithography process, enabling the integration of perovskite arrays into image sensors and displays.

electrical, and defect characteristics because carriers preferably move within the covalently bonded ribbons. Sb 2 Se 3 is a narrow band gap material with a bandgap energy of 1-1.2 eV, which can be tuned by controlling the annealing temperature. [4][5][6] Furthermore, Sb 2 Se 3 has great potential for use as a light absorber because of its high absorption coefficient (over 10 5 cm −1 in the visible light region), low toxicity, and abundance in nature, as well as its coverage of a wide response spectrum ranging from the ultra-violet (UV) to the NIR region. Despite these promising characteristics, the intrinsically low electrical conductivity of Sb 2 Se 3 remains a challenge that needs to be addressed. [7] In this regard, researchers have extensively researched Sb 2 Se 3 nanostructures, such as nanowires and nanorods, to improve their electrical conductivity because single crystals help carriers to move easily. Most of the reported Sb 2 Se 3 nanostructures were synthesized using chemical vapor deposition, which is intricate and necessarily uses chemical precursors and requires high reaction temperatures, typically between 300 and 900 °C. [8][9][10] Polycrystalline Sb 2 Se 3 thin films represent an alternative avenue for conductivity enhancement. Polycrystalline Sb 2 Se 3 thin films were prepared using various methods including vapor deposition technology, thermal evaporation, chemical bath technology, and sputtering. [2,4,6,[11][12][13] Among them, the sputtering method is considered the most suitable for thin film deposition because it offers precise control over the deposition parameters, a high film growth rate, and a relatively low cost compared to chemical vapor deposition. [5,14,16] However, during the sputtering process, selenieum (Se) loss occurs owing to the high vapor pressure of Se. To compensate for this loss, a selenization process has been adopted in various ways. For instance, Shongalova and co-workers selenized Sb 2 Se 3 thin films under hazardous H 2 Se gas flows, where, by starting with Sb-Se precursors, they deposited Sb 2 Se 3 films by means of RF magnetron sputtering. [14] Thus far, sputter-deposited Sb 2 Se 3 thin films have been mainly used to fabricate solar cells. [13][14][15][16][17] In other words, co-sputtered Sb 2 Se 3 selenization was performed mainly to improve the performance of solar cells, and studies related to Sb 2 Se 3 thin-film-based PDs have not been conducted yet.In this study, for the first time, we report the realization of high-responsivity selenized Sb 2 Se 3 -based NIR PDs by focusing on the effect of annealing temperature on device performance. Sb 2 Se 3 has great potential for applications in near-infrared sensors because of its narrow bandgap, environmental friendliness, and high absorption coefficient. However, the low conductivity of Sb 2 Se 3 is an obstacle to the further development of high-performance optoelectronic devices. In this study, to address this challenge, the selenization process is adopted. The incorporation of Se atoms into Sb 2 Se 3 facilitates the ...

In article number 2105485, Tae-Yeon Seong and co-workers experimentally demonstrate dynamic photoadaptation behavior of an integrated optoelectronic device array that mimics the functionality of the biological visual nervous system. The device array, which is designed to adapt to repeated optical stimuli that change according to external conditions, exhibits excellent performance. This autonomic response to stimuli is essential to the improvement of nextgeneration bionic electronics.