Performance enhancement of AlGaN deep-ultraviolet laser diode using compositional Al-grading of Si-doped layers

• Published in: Optics and laser technology Vol. 152; p. 108156
• Main Authors: Sharif, Muhammad Nawaz, Ajmal Khan, M., Wali, Qamar, Demir, Ilkay, Wang, Fang, Liu, Yuhuai
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.08.2022; Elsevier BV
• Subjects: Aluminum gallium nitrides; Carrier injection; Cladding layer; Compositional grading of AlGaN; Confinement; Current density; Deep-ultraviolet laser diode; Performance enhancement; Semiconductor lasers; Silicon; Threshold currents; Ultraviolet lasers; Waveguide layer; Waveguides; Deep-ultraviolet laser diode; Compositional grading of AlGaN; Cladding layer; Waveguide layer
• ISSN: 0030-3992; 1879-2545
• DOI: 10.1016/j.optlastec.2022.108156

•Compositional grading of AlGaN layers is used to increase the optical confinement factor (OCF), and gain of DUV LD.•Compositional grading of waveguides (WGs), electron blocking layer (EBL), and cladding layers (CLs) demonstrated that the device characteristic can be improved.•Along with WGs and EBL grading Si-doped CL improved the OCF and gain of DUV LD. Achieving high threshold current density and high optical confinement are big challenges in the realization of high-performance aluminum gallium nitride (AlGaN)-based deep-ultraviolet (DUV) laser diode (LD). In this work, compositional Al-grading of AlGaN layers is used to increase the optical confinement factor (OCF), carrier injection efficiency, gain, and emission power of the DUV LD. Compositional grading of waveguides (WGs) layer, electron blocking layer (EBL), and cladding layers (CLs) demonstrated that the device characteristic can be improved. By using compositional Al-grading of AlGaN p-WG, EBL, p-CL along with n-WG and n-CL, 17.4% OCF, 94.4 mW emission power, and 1369 m−1 gain at 267 nm peak emission wavelength are achieved. These improvements are attributed to the reduced threshold current density as well as using better optical confinement scheme in the DUV LD.