Colloidal Zn-based Semiconductor Nanocrystals: Recent Advances and Challenges

In the past decades, benefitting from the development of synthesis methodology, Cd-based semiconductor nanocrystals (NCs) have been extensively studied and their structure-dependent properties further inspired diverse applications. However, the high toxicity of Cd in Cd-based semiconductor NCs significantly limits their widespread applications. Colloidal Zn-based semiconductor NCs are one of the most promising candidates for Cd-based semiconductor NCs attributed to their low toxicity, creating high-band gap systems with excellent optoelectronic properties. Herein, an overview of the synthesis, structure engineering, and optoelectronic applications of colloidal Zn-based semiconductor NCs are provided. In the first section, the typical growth mechanisms are introduced, including oriented attachment, templated-assisted growth, and ripening. Then, structure engineering, such as core–shell structure, heterostructure, alloying, and doping, of Zn-based NCs are summarized. Simultaneously, an insight into various applications related to these structures of Zn-based NCs are given, including quantum dots light emitting diodes (QLEDs), catalysts, biological-application, sensors, and solar cells. Finally, although huge progress in both synthesis methodology and applications of colloidal Zn-based semiconductor NCs have been achieved, some issues still hinder the further development of Zn-based semiconductor NCs. Then in the last section, it is elaborated on the challenges and provides the possible solutions to tackle these challenges.