Recent Advances in Low-Dimensional Organic–Inorganic Hybrid Metal Halides (0D–2D) for Solid-State Lighting

The lighting industry has undergone significant changes over the past decade, lead-based low-dimensional metal halides exist as electroluminescent diodes (LEDs) and possess significant potential because of their external quantum efficiency (EQE) exceeding 25%. However, the lead toxicity and instability of the device hindered its commercialization. At present, an effective way to solve these problems is to replace lead (Pb²⁺) with low-toxicity or non-toxic metal ions to form lead-free metal halides. In this paper, the synthesis of recent novel low-dimensional hybrid metal halides based on Pb, Cu, Mn, Sb, Sn, etc. metals is reviewed, and their photoluminescence mechanism is discussed. From the perspective of material evolution and challenges, this summarizes the progress made in low-dimensional metal hybrid halides for white light-emitting diodes (WLEDs), and it discusses the limitations of current WLEDs materials, aiming to point out an encouraging outlook for its future development in solid-state lighting.