Sputtered gold nanoparticles enhanced quantum dot light-emitting diodes

Surface plasmonic effects of metallic particles have been known to be an effective method to improve the performances of light emitting didoes. In this work, we report the sputtered Au nanoparticles enhanced electroluminescence in inverted quantum dot light emitting diodes (ITO/Au NPs/ZnMgO/QDs/TFB/PEDOT:PSS/Al). By combining the time-resolved photoluminescence, transient electroluminescence, and ultraviolet photoelectron spectrometer measurements, the enhancement of the internal field enhanced exciton coupling to surface plasmons and the electron injection rate increasing with Au nanoparticles' incorporation can be explained. Phenomenological numerical calculations indicate that the electron mobility of the electron transport layer increases from 1.39 × 10−5 cm2/V⋅s to 1.91 × 10−5 cm2/V⋅s for Au NPs modified device. As a result, the maximum device luminescence is enhanced by 1.41 fold (from 14600 cd/cm2 to 20720 cd/cm2) and maximum current efficiency is improved by 1.29 fold (from 3.12 cd/A to 4.02 cd/A).