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

In this paper, a method of indium-tin oxide/Au/indium-tin oxide (IAI) structure as transparent conductive layers (TCLs) 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.

Automated summary

This paper investigates a method of using indium-tin oxide/Au/indium-tin oxide (IAI) structure as transparent conductive layers (TCLs) to improve the current spreading and suppress efficiency droop of UV-LEDs. The morphology and distribution of Au clusters formed by annealing are studied using atomic force microscope and scanning electron microscope. Results show that with the insertion of an Au interlayer, the forward voltage of UV-LED decreases by 5.9% at 20 mA and the light output power and wall plug efficiency increase by 64.2% and 84.2% at 300 mA. Furthermore, the current distribution becomes more uniform and the current spreading characteristics of UV-LED are improved.