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Chinese purple (CP), an ancient traditional pigment, represents the rich cultural and scientific heritage of an ancient civilization. To achieve high‐purity CP pigment in a more economical and efficient manner, we synthesized CP using a low‐temperature hydrothermal route. Interestingly, we observed the emergence of an emission peak at 894 nm in CP under irradiation at λex = 650 nm. Additionally, it was noted that the CP powder exhibited a significant photothermal effect when exposed to near‐infrared light irradiation. A photothermal conversion efficiency of 19% was achieved in the CP pigment. This study not only sheds light on the enigmatic nature of this ancient pigment but also highlights its potential as a critical photothermal conversion material. [ABSTRACT FROM AUTHOR]

In recent years, broadband near-infrared (NIR) spectroscopy has attracted widespread research attention. However, the development of broadband NIR-emitting phosphors with superior thermal stability under excitation by near-ultraviolet or blue LED chips remains a challenge. Furthermore, silicon nanostructured materials exhibit unique photoelectric properties and environmentally friendly characteristics. While the study of crystalline silicon nanoparticles has garnered significant attention, research on amorphous structures remains limited. In this study, we synthesized amorphous silicon nanoparticles (a-Si NPs) with a wide near-infrared emission ranging from 600 nm to 1000 nm, achieved through a sol–gel derived polymer and a subsequent heat treatment process. The surface of a-Si NPs was effectively passivated by secondary annealing, resulting in enhanced near-infrared emission. Additionally, these nanoparticles displayed a NIR fluorescence emission peak at 812 nm with a full width at half maximum (FWHM) of 169 nm, alongside remarkable thermal stability. Consequently, the integrated NIR pc-LED device demonstrated outstanding night vision imaging capabilities. As an accurate fingerprint developer, it provides enhanced imaging on various substrates to reveal detailed features. The findings suggest that the a-Si NP phosphor has considerable potential for applications in night vision imaging and could make significant contributions to fingerprint detection technology. This research provides a valuable reference for the exploitation and further development of amorphous silicon-based optical materials. [ABSTRACT FROM AUTHOR]

The crystallization behavior of halide perovskites is of great significance. Fractal structures, featured by self-similarity between local morphology and global structures, have consistently captivated scientists' interest across diverse disciplines. In this study, we realized the fractal patterns in lead-free zero-dimensional (0D) Cs2InBr5(H2O) perovskites. By depositing saturated precursor droplets on silicon or glass substrates, we initiated nucleation and crystallization of 0D Cs2InBr5(H2O) crystals on the liquid's upper surface. As the solution evaporated, the remaining high-concentration solution formed self-similar fractal patterns beneath the Cs2InBr5(H2O) crystals. This anisotropic growth mechanism imparted a unique self-assembly behavior to 0D Cs2InBr5(H2O). Additionally, X-ray diffraction results confirmed distinct preferential orientations of the fractal patterns. The findings of this work provide valuable insights into the controlled crystallization behavior of lead-free perovskites and inspire further exploration of novel optoelectronic properties arising from such a unique fractal pattern. [ABSTRACT FROM AUTHOR]