240 nm AlGaN-based deep ultraviolet micro-LEDs:size effect versus edge effect

作     者：Shunpeng Lu Jiangxiao Bai Hongbo Li Ke Jiang Jianwei Ben Shanli Zhang Zi-Hui Zhang Xiaojuan Sun Dabing Li Shunpeng Lu;Jiangxiao Bai;Hongbo Li;Ke Jiang;Jianwei Ben;Shanli Zhang;Zi-Hui Zhang;Xiaojuan Sun;Dabing Li

作者机构：State Key Laboratory of Luminescence and ApplicationsChangchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China Center of Materials Science and Optoelectronics EngineeringUniversity of Chinese Academy of SciencesBeijing 100049China Key Laboratory of Electronic Materials and Devices of TianjinSchool of Electronics and Information EngineeringHebei University of TechnologyTianjin 300401China 

出 版 物：《Journal of Semiconductors》 (半导体学报（英文版）)

年 卷 期：2024年第45卷第1期

页      面：55-62页

核心收录：

学科分类：080901[工学-物理电子学] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 080401[工学-精密仪器及机械] 0804[工学-仪器科学与技术] 0803[工学-光学工程] 

基　　金：This work was supported by National Key R&D Program of China(2022YFB3605103) the National Natural Science Foundation of China(62204241,U22A2084,62121005,and 61827813) the Natural Science Foundation of Jilin Province(20230101345JC,20230101360JC,and 20230101107JC) the Youth Innovation Promotion Association of CAS(2023223) the Young Elite Scientist Sponsorship Program By CAST(YESS20200182) the CAS Talents Program(E30122E4M0) 

主　　题：AlGaN deep ultraviolet micro-LEDs light extraction efficiency size effect edge effect 

摘      要：240 nm AlGaN-based micro-LEDs with different sizes are designed and ***,the external quantum efficiency(EQE)and light extraction efficiency(LEE)are systematically investigated by comparing size and edge ***,it is revealed that the peak optical output power increases by 81.83%with the size shrinking from 50.0 to 25.0μ***,the LEE increases by 26.21%and the LEE enhancement mainly comes from the sidewall light *** notably,transversemagnetic(TM)mode light intensifies faster as the size shrinks due to the tilted mesa side-wall and Al reflector ***,when it turns to 12.5μm sized micro-LEDs,the output power is lower than 25.0μm sized *** underlying mechanism is that even though protected by SiO2 passivation,the edge effect which leads to current leakage and Shockley-Read-Hall(SRH)recombination deteriorates rapidly with the size further ***,the ratio of the p-contact area to mesa area is much lower,which deteriorates the p-type current spreading at the mesa *** findings show a role of thumb for the design of high efficiency micro-LEDs with wavelength below 250 nm,which will pave the way for wide applications of deep ultraviolet(DUV)micro-LEDs.