Broadband emissive I-III-VI quantum dots (QDs) are synthesized as efficient and stable I-III-VI QDs to be used as eco-friendly luminescent materials in various applications. Here, we introduce the additional passivation of zirconium isopropoxide (Zr(i-PrO)4) to improve the optical properties and environmental stability of green-emitting CuGaS2/ZnS (G-CGS/ZnS) and red-emitting CuInS2/ZnS (R-CIS/ZnS) QDs. The photoluminescence quantum yield (PLQY) of both resultant Zr(i-PrO)4-coated G-CGS/ZnS and R-CIS/ZnS QDs reaches similar values of ~ 95%. In addition, the photostability and thermal-stability of G-CGS/ZnS/Zr(i-PrO)4 and R-CIS/ZnS/Zr(i-PrO)4 QDs are improved by reducing the ligand loss via encapsulation of the ligand-coated QD surface with Zr(i-PrO)4. It is also proved that the Zr(i-PrO)4-passivated interlayer mitigates the further degradation of I-III-V QDs from ligand loss even under harsh conditions during additional hydrolysis reaction of aluminum tri-sec-butoxide (Al(sec-BuO)3), forming easy-to-handle G-CGS/ZnS and R-CIS/ZnS QD-embedded Al2O3 powders. Therefore, the introduction of a Zr(i-PrO)4 complex layer potentially provides a strong interlayer to mitigate degradation of I-III-VI QD-embedded Al2O3 hybrid powders as well as passivation layer for protecting I-III-VI QD.
Keywords: Hydrolysis; I–III–VI quantum dots; QD doping; Stability; Surface passivation.
© 2022. The Author(s).