Improved Efficiency Droop of 370 nm UV LEDs with ITO/Au/ITO Structure

Abstract

A method of indium-tin oxide /Au/ indium-tin oxide (IAI) structure as transparent conductive layer to improve the current spreading and suppress efficiency droop of ultraviolet light-emitting diodes (UV-LEDs) is investigated. The morphology and distribution of Au clusters formed by annealing are investigate by atomic force microscope and scanning electron microscope. Compared with the UV-LED without Au clusters, the forward voltage of UV-LED is reduced by 5.9% at 20 mA, light output power and wall plug efficiency increase by 64.2% and 84.2% at 300 mA for the UV-LED with IAI structure as the thickness of the Au interlayer is 1 nm. In addition, light emission distribution results show that by inserting Au interlayer, current distributes more uniform and the current spreading characteristics of UV-LED are improved. Ultimately, efficiency droop of the LED has been suppressed.

A patterning technology of transfer-free graphene for transparent electrodes of near-ultraviolet light-emitting diodes

“…Indium tin oxide (ITO) is the most representative transparent electrode material widely used in various light-emitting devices. [9][10][11] Compared with it, graphene has significantly higher transmittance in the ultraviolet band, 12 has better performance on flexible substrates, [13][14][15] and is more environmentally friendly because ITO contains the rare metal indium. In addition, with the development of graphene-doping technology and graphene composite electrodes, the photoelectric performance of graphene transparent electrodes has been further improved.…”