Heavy-Metal-Free Heterostructured Nanocrystals for Light-Emitting Applications

Rising demands on environmentally benign materials lead to the development of heavy-metal-free NCs for light-emitting applications. Tremendous efforts to solve the challenges of heavy-metal-free NCs have been focused on the discovery of synthetic chemistry and photophysical properties of the NCs. This review provides a comprehensive overview of the progress in the synthesis of heavy-metal-free semiconductor NCs, mainly focusing on III–V, I–III–VI₂, and II–VI groups. The progress details the discovery of their precursor chemistry and the formation of heterostructures to fit their chemical nature and photophysical properties. The continuous efforts on the structural design and synthetic chemistry reveal how exceptional properties of the NCs materialized. The remarkable progress in photophysical properties and synthetic chemistry on the NCs supports the potential of these NCs in optoelectronic applications, including light-emitting diode (LED) and solar cell, demonstrating their suitability as strong alternatives to Cd and Pb-based NCs. This review offers insights into the remaining challenges of the NCs, directing the future perspectives of the NCs.