Efficiency Enhancement of Quantum-Dot-Converted LEDs by 0D–2D Hybrid Scatterers

Light conversion-efficiency (LCE) remains key challenge for application of quantum dots (QDs) converted light-emitting diodes (QCLEDs) due to fluorescence quenching of concentrated QDs. Here, we developed an optical scatterer made of assembled 0D SiO2 nanospheres and 2D BN nanoplates and studied their mechanisms to improve the LCE of QCLEDs. Experiment and finite-difference time-domain (FDTD) analysis reveal the 0D–2D hybrid structure integrates the optical characteristics of the forward-scattering from the 0D SiO2 sphere and backward-scattering of blue light from the 2D BN plate. The resulting 0D–2D hybrid scatterers at the appropriate SiO2/BN ratio balance the backward- and forward-scattered light and, hence, maximize the excitation light absorption and the light extraction of QCLEDs at low QD concentration. We demonstrated that the LCE of the QCLEDs with SiO2–BN scatterers is increased by 99%, 13%, and 27% as compared to the QCLEDs without scatterers and with individual 0D SiO2 and 2D BN scatterers, respectively. The hybrid scatterers also show extra economic value by saving up to 75% of QDs in QCLEDs at the same light output.