Study of Energy Transfer Dynamic in Mixed Quantum Dots for On-Chip White Light-Emitting Diodes

Recent advancements in quantum dot (QD)-converted light-emitting diodes (Qc-LEDs) require on-chip deposition of mixed QDs to achieve a wide color gamut and efficient displays. However, high QD concentrations lead to significant near-field energy transfer, causing fluorescence quenching and color shifting. A thorough understanding of energy transfer dynamics between QDs is essential for minimizing energy loss and color variation in Qc-LEDs. In this study, we investigate the energy transfer processes between various green-emitting QDs and red-emitting quantum rods (QRs), focusing on how their heterostructure and morphology influence the energy transfer kinetics. Through steady-state and transient photoluminescence and absorption measurements, we identify a bidirectional energy transfer between QDs and QRs at high concentrations, influenced by their concentration, morphology, and band alignment within the heterostructures. By optimizing parameters such as rod length, QD structure, and concentration, we identify the ideal configuration of mixed QDs and QRs that maximizes system efficiency. These results provide valuable insights into the design of mixed QD systems, offering strategies to optimize light conversion in Qc-LEDs and advance the development of high-performance displays.