Intense pulsed light (IPL) annealed sol–gel derived ZnO electron injector for the production of high efficiency inverted quantum dot light emitting devices (QLEDs)

Room temperature intense pulsed light annealing (photonic annealing, pulsed forge) renders the sol-gel derived ZnO films highly conductive and hydrophobic with improved interface with the colloidal quantum dots. The IPL annealed ZnO proved to be a better electron transporter/injector in inverted devices with QDs. Both the current and power efficiencies of red devices comprising IPL annealed ZnO were 13.75 and 37.5 fold higher than the identical devices produced with thermally annealed ZnO. The lifetime of the devices with IPL annealed ZnO was found to be fivefold longer than the thermally annealed ZnO counterpart. Thermally aged devices comprising IPL annealed ZnO gave a maximum current efficiency of 23 cd A(-1) and a power efficiency of 30 lm W-1.