Controllable synthesis of Cu-based quantum dots/nanocrystals and application in white light-emitting diodes

Abstract

Lead-free copper-based quantum dots (QDs)/nanocrystals (NCs) with a facile preparation method and low price are promising candidates for replacing traditional expensive phosphors for applications in white light-emitting diodes (W-LEDs). In this article, the strategy of secondary excitation of red CIS/ZnS core–shell QDs using green Cs₃Cu₂Cl₅ NCs and blue Cs₃Cu₂I₅ NCs was employed. UV-excited W-LEDs with a unique (GB)_nR_m layered structure was successfully prepared using green Cs₃Cu₂Cl₅ NCs, blue Cs₃Cu₂I₅ NCs and red CIS/ZnS core–shell QD composite materials with different luminescence wavelengths. At the same time, the properties of the synthesized CuInS₂ (CIS) QDs, CuInS₂/ZnS core–shell QDs and Cs₃Cu₂X₅ (X = C1, Br, I) NCs were characterized and the effect of myristic acid (MA) on the optical properties was discussed. This study has an important reference significance on how to use three different quantum dots/nanocrystals to fabricate W-LEDs.