Chiral CdSe/CdS quantum dot (in rod)-light-emitting diodes with circularly polarized electroluminescence
Tianwei Duan, Jing Ai, Sujie Chen, Gufeng He, Xiaojun Guo, Lu Han, Shunai Che, Yingying Duan
Abstract
Chiral quantum dot (in rod)-light-emitting diodes (CQLEDs) with circularly polarized electroluminescence (CPEL) have driven interest in the future display, communication, and storage industries. However, the preparation of CQLEDs is still a challenging unresolved. Herein, we fabricated CQLEDs through spin-coating evaporation of chiral CdSe/CdS quantum rods (CCCQs) colloidal solution on indium tin oxide substrate. The CCCQs were synthesized via an isotropically epitaxial growth with cholic acid as the symmetry breaking agent, which induced one-direction chiral dislocation around the c axis of their hexagonal crystal structure. The CCCQs were ranked side-by-side in right-handed chiral arrangement with helical axis perpendicular to substrate due to chiral driving force of the cholic acid arrangement. The CQLEDs exhibited a negative CPEL signal at 600 nm with a |gEL| of 2 × 10−4, which is ascribable to the selective filtration on emission arising from the circular Bragg resonance by quasi-photonic crystal structures.