Colloidal ZnInGaS Nanocrystals with Wide‐Band Gap for Ultraviolet Emitters

Abstract Colloidal wide band gap semiconductor nanocrystals (NCs) are the potential ultraviolet range materials for light‐emitters and photodetectors. ZnInGaS NCs with wide band gaps are produced with the intermediate of multinary ZnInGaS magic sized clusters. With the surface etching and intermediate shell design, ZnInGaS/ZnGaS/ZnS core/shell NCs exhibit the band‐edge fluorescence emission at 394 nm and the record photoluminescent quantum yield of 18.3% in Cd‐free ultraviolet emitters. The band gap in ZnInGaS NCs can be tuned from 3.20 to 3.75 eV via the changed size and composition, showing the adjusted fluorescence emission from 366 to 420 nm, which is widely tunable in the range. Finally, the NCs are integrated into a graphene transistor, obtaining a visible‐blind ultraviolet photodetector. This study underscores the potential of ZIGS NCs for UV emission and highlights their broader applicability in optoelectronic devices, demonstrating their significant potential for practical applications.