关键词: 深紫外 LED, 隧道结, 铝镓氮, 氮化物半导体

Abstract: Aiming at the problems of low luminous efficiency and large working bias of AlGaN-based deep-UV (Ultraviolet) LEDs (Light Emitting Diodes), a nitrogen-polar AlGaN-based deep-UV LED device structure with n ⁺ -GaN/ Al _{0. 4}Ga_{0. 6}N/ p ⁺ -GaN tunnel junction is designed. The LED structure is consist of an electron supplying layer n-Al _{0. 65}Ga_{0. 35}N, a multiple quantum wells of Al _{0. 65} Ga_{0. 35} N/ Al _{0. 5} Ga_{0. 5} N, a compositionally graded p-Al _xGa1_-xN and n ⁺ -GaN/ Al _{0. 4}Ga_{0. 6}N/ p ⁺ -GaN tunnel junction. The simulation results show that the tunnel junction LED has higher internal quantum efficiency and light output power, and it has a lower turn-on voltage than the reference LED without tunnel junction. The improvement of the optoelectronic characteristics of the tunnel junction LED is attributed to the introduction of the tunnel junction improving the hole injection efficiency of the LED, and improving the current spreading capability of the LED device. The results of this work show that the simulation of carrier transport and optoelectronic characteristics of semiconductor devices through simulation software is helpful deepening the understanding of the physical characteristics of semiconductor devices. If the study of semiconductor device simulation software is added to the learning process of “ semiconductor device physics冶, it will help the cultivation of talents in the semiconductor field. 

Key words: deep ultraviolet light emitting diodes (LED), tunnel junction, aluminum gallium nitride(AlGaN), nitride semiconductor