Passivation and Interlayer Effect of Zr(i-PrO) on Green CuGaS/ZnS/Zr(i-PrO)@AlO and Red CuInS/ZnS/Zr(i-PrO)@AlO QD Hybrid Powders.

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)) to improve the optical properties and environmental stability of green-emitting CuGaS/ZnS (G-CGS/ZnS) and red-emitting CuInS/ZnS (R-CIS/ZnS) QDs. The photoluminescence quantum yield (PLQY) of both resultant Zr(i-PrO)-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) and R-CIS/ZnS/Zr(i-PrO) QDs are improved by reducing the ligand loss via encapsulation of the ligand-coated QD surface with Zr(i-PrO). It is also proved that the Zr(i-PrO)-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)), forming easy-to-handle G-CGS/ZnS and R-CIS/ZnS QD-embedded AlO powders. Therefore, the introduction of a Zr(i-PrO) complex layer potentially provides a strong interlayer to mitigate degradation of I-III-VI QD-embedded AlO hybrid powders as well as passivation layer for protecting I-III-VI QD.