Progress on solid-state synthesis and photoluminescence applications of all-inorganic metal halide perovskite nanocrystals

In recent years, all-inorganic metal halide perovskite nanocrystals (NCs) have emerged as promising optoelectronic materials due to their exceptional optical properties, including high photoluminescence (PL) quantum yields (PLQYs > 90%), extremely narrow full width at half maximum (FWHM < 30 nm), broadly tunable emission spectra, and short decay lifetimes. However, extensive reviews exist on colloidal perovskite NCs synthesized via solution-related methods. Here, this review uniquely focuses on solid-state synthesis of bulk and powder NCs. And a comprehensive overview of the latest advancements in solid-state synthesis techniques is provided, including high-energy ball milling, high-temperature solid-state synthesis (molten salt synthesis and template-confined synthesis), and glass matrix encapsulation. Furthermore, the PL applications of all-inorganic metal halide perovskite NCs in white light-emitting diodes (LEDs), micro LEDs (μ-LEDs), liquid crystal display (LCD) backlight, anti-counterfeiting, and x-ray are discussed in detail, emphasizing their superior performance in terms of color purity, brightness, and stability. Ultimately, the current challenges, including defect regulation, stability of iodine-based materials, and in-depth understanding of template growth mechanisms are still bottlenecks hindering further research. This review may assist researchers in developing the solid-state synthesis of all-inorganic metal halide perovskite NCs and applying this synthesis method to next-generation optoelectronic devices.