Rising demands on environmentally benign materials lead to the development of heavy-metal-free NCs for light-emitting

applications. Tremendous eff orts 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–VI 2 , and II–VI groups. The progress

details the discovery of their precursor chemistry and the formation of heterostructures to fi t their chemical nature and

photophysical properties. The continuous eff orts 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 off ers insights into the remaining

challenges of the NCs, directing the future perspectives of the NCs.