High-Efficiency Deep-Ultraviolet Light-Emitting Diodes With Efficient Carrier Confinement and High Light Extraction

• Published in: IEEE transactions on electron devices Vol. 66; no. 2; pp. 976 - 982
• Main Authors: Chang, Jih-Yuan, Liou, Bo-Ting, Huang, Man-Fang, Shih, Ya-Hsuan, Chen, Fang-Ming, Kuo, Yen-Kuang
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.02.2019; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: AlGaN; Aluminum gallium nitride; carrier confinement; Confinement; Light emitting diodes; light extraction; light-emitting diodes (LEDs); Mathematical model; Optical polarization; Optical properties; Organic light emitting diodes; Parameter sensitivity; Physical properties; Piezoelectric polarization; polarization effect; Quantum efficiency; Quantum wells; Radiative recombination; Ultraviolet radiation; Wide band gap semiconductors
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2018.2887074

In deep-ultraviolet (DUV) light-emitting diodes (LEDs), it is difficult to obtain both efficient carrier confinement and high light extraction, which are quite sensitive to optical polarization and other physical parameters. In this paper, characteristics of DUV LEDs with various n-AlGaN layers and quantum barriers (QBs), and various widths of quantum wells (QWs) are investigated. Specifically, the capability of carrier confinement and properties of optical polarization are analyzed in detail. The simulation results show that LED structure with Al 0.64 Ga 0.36 N QBs, n-Al 0.7 Ga 0.3 N layer, and 4-nm-thick QWs, which has a peak emission wavelength of 284.5 nm at 60 mA, exhibits high internal quantum efficiency of 25% and high degree of optical polarization of 0.874.