Researchers at The Hong Kong Polytechnic University (PolyU) have developed a dual-defect suppression strategy, achieving record-breaking luminescence in lead-free quantum materials, opening new possibilities for advanced optoelectronic applications. Lead-free perovskite nanomaterials are regarded as safer and more environmentally friendly alternatives for next-generation optoelectronic devices. However, tin halide perovskite nanocrystals have suffered from poor luminescence. Prof. Jun YIN, Assistant Professor of the Department of Applied Physics at PolyU, has addressed this challenge through computationally guided dual-defect suppression strategy, achieving a record photoluminescence quantum yield (PLQYs) of 42.4%, more than 80 times higher than previous reports.
In recent years, perovskite nanocrystals have attracted growing attention for use in optoelectronic devices that are closely connected to our daily life, ranging from the vibrant displays of smartphones and televisions to the next-generation of solar cells and photodetectors. However, the most efficient perovskite materials to date have relied heavily on lead, a toxic element that poses significant environmental and health risks. This has spurred an urgent search for safer, lead-free alternatives that do not compromise on performance.
Among the most promising candidates are tin halide perovskite nanocrystals, which have the potential to replace lead in perovskite-based devices and pave the way for a new era of sustainable quantum materials. Despite this promise, tin-based perovskites have been plagued by low PLQYs and poor stability, limiting their practical application. These challenges stem largely from the complex defect chemistry of tin halide perovskites, which has so far resisted conventional synthetic strategies.
To address this long-standing challenge, Prof. YIN and his research team leverage computational insights to guide the synthesis of tin halide perovskite nanocrystals with unprecedented luminescence. Their key breakthrough was the development of a dual-defect suppression strategy that combines tin-rich reaction conditions with the incorporation of exogenous monovalent cations, thereby suppressing both bulk and surface defects. Using this approach, the team successfully synthesized FASnI3 (FA = formamidinium) nanocrystals with a PLQY of 42.4% ± 1.0%, more than 80 times higher than previously reported for this material. This breakthrough, published in Nature Synthesis, not only deepen the understanding of defect chemistry in tin perovskites, but also provides a practical pathway toward high-performance, lead-free quantum materials for optoelectronic applications.
This study demonstrates that computationally guided synthesis, grounded in a deep understanding of defect chemistry, can unlock the full potential of tin halide perovskite nanocrystals as high-efficiency, lead-free quantum materials.
Source: Innovation Digest
