Highly efficient near ultraviolet LEDs using InGaN/GaN/AlxGa1-xN/GaN multiple quantum wells at high temperature on sapphire substrate

This work demonstrated the highly efficient near-ultraviolet (UV) light-emitting diodes (LEDs) grown on sapphire substrates with InGaN/GaN/AlxGa1-xN/GaN multiple-quantum wells (MQWs), where x is the number of Al composition. The proposed GaN/AlxGa1-xN/GaN quantum barrier and InGaN quantum well of UV-GaN based LED has successfully grown using metal-organic chemical vapor deposition. The result reveals that the GaN/AlxGa1-xN/GaN barrier has higher light output power and lower current leakage than the GaN barrier. A significant increase in wall-plug efficiency was observed at the same wavelength range. The proposed structure in this study serves two functions: it increases the barrier bandgap to enhance carrier confinement. Second, promoting v-pit in the MQW layer may reduce the current resistance while increasing hole mobility. As a result, the internal quantum efficiency (IQE) may increase and lower electrical power consumption while enhancing performance.