LAUSR

Short-wavelength light-emitting diodes (LEDs), a prevalent research topic in modern optoelectronics, have attracted considerable attention in recent years because of their vast application potential in both civil and military domains. Herein, blue-violet LEDs are constructed via a spin-coating solution-processed ZnO quantum dots (QDs) onto p-GaN: Mg wafers. By inserting a thin Al2O3 dielectric retarding layer into the ZnO QDs side, electrons injected from ITO cathode are effectively slowed and detained in the QDs emissive layer, resulting in a ≈30-fold improvement of near-UV electroluminescence intensity from this p-GaN/ZnO QDs/Al2O3/ZnO QDs LED. Furthermore, by replacing pure ZnO QDs with Ag@ZnO hybrid nanodots (synthesized through a simple one-step wet chemical route) as the electron transport layer, the device electroluminescence intensity is further increased. Time-resolved and temperature-dependent spectroscopy reveals that both the spontaneous emission rate and internal quantum efficiency of the ZnO QDs active layer are simultaneously increased as a result of the exciton-localized surface plasmon resonant coupling, which leads to the observed blue-violet electroluminescence enhancement.