Enhanced electroluminescence from ZnO quantum dot light-emitting diodes by introducing AZO/Ag NWs/AZO composite film cathode

Short-wavelength light-emitting diodes (SWLED) have received exclusive attention due to their widespread applications. Zinc oxide (ZnO) quantum dots (QDs) are considered ideal materials for SWLED, and they have been used in building ZnO quantum dot light emitting diodes (QLED). However, the electroluminescence (EL) performance of the ZnO QLED is still low. Herein, Aluminum-doped ZnO/ Silver nanowires/Aluminum-doped ZnO (AZO/Ag NWs/AZO) composite film is prepared to serve as the cathode of ZnO QLED, resulting in an enhancement of the near-UV emission of the device by about 81%. Time-resolved and temperature-dependent spectroscopy analysis shows that the observed EL enhancement is from the improved spontaneous emission rate and internal quantum efficiency (IQE) by the resonance coupling between ZnO QDs excitons and Ag NWs surface plasmon. The research may impact applications of ZnO QLED in the field of short-wavelength luminescence.