Lead‐Free Halide Perovskite Nanocrystals: Crystal Structures, Synthesis, Stabilities, and Optical Properties

• Published in: Angewandte Chemie International Edition 2020-01, Vol.59 (3), p.1030-1046
• Main Authors: Fan, Qianqian, Biesold‐McGee, Gill V., Ma, Jianzhong, Xu, Qunna, Pan, Shuang, Peng, Juan, Lin, Zhiqun
• Format: Article
• Language: English
• Subjects: Charge transport; Crystal structure; Crystals; Lasers; Lead compounds; lead-free perovskites; Metal halides; Moisture resistance; Nanocrystals; Optical properties; Organic light emitting diodes; Perovskites; Photoluminescence; Photons; Photovoltaic cells; Solar cells; Synthesis; Toxicity; Transport properties
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201904862

In recent years, there have been rapid advances in the synthesis of lead halide perovskite nanocrystals (NCs) for use in solar cells, light emitting diodes, lasers, and photodetectors. These compounds have a set of intriguing optical, excitonic, and charge transport properties, including outstanding photoluminescence quantum yield (PLQY) and tunable optical band gap. However, the necessary inclusion of lead, a toxic element, raises a critical concern for future commercial development. To address the toxicity issue, intense recent research effort has been devoted to developing lead‐free halide perovskite (LFHP) NCs. In this Review, we present a comprehensive overview of currently explored LFHP NCs with an emphasis on their crystal structures, synthesis, optical properties, and environmental stabilities (e.g., UV, heat, and moisture resistance). In addition, strategies for enhancing optical properties and stabilities of LFHP NCs as well as the state‐of‐the‐art applications are discussed. With the perspective of their properties and current challenges, we provide an outlook for future directions in this rapidly evolving field to achieve high‐quality LFHP NCs for a broader range of fundamental research and practical applications. Taking the lead: This Review summarizes recent advances in widely studied lead‐free halide perovskite nanocrystals, centering on understanding their crystal structures, synthesis methods, environmental stability, and optical properties. The challenges in this rapidly evolving field and opportunities to further improve the quality and stability of these nanocrystals are also provided.