In this paper, we have analyzed the performance of laser diodes (LDs) with an undoped In x Ga 1−x N waveguide in association with variable In mole fractions varying from 0% to 6%. The InGaN waveguide significantly affected optical confinement and carrier dynamics in the LD. Laser output power, internal quantum efficiency (IQE), quantum well (QW) gain and optical confinement factor (OCF) are analyzed in correlation with In content in the waveguide. The OCF for TE1 mode at x = 0 is 0.0079, and it increases with x. The OCF for x = 0.06 is 0.0109. Quantum states in the QW reduced with In content, which reduced QW gain. However, improved OCF consequently improved the overall gain of the device. Peak IQE for x = 0 is ~0.28, which increased to ~0.683 for x = 0.06. Laser output power, slope efficiency and IQE improved with increasing In content. The threshold current density for x = 0 is 3.911 kA cm −2 , which drops to 1.806 kA cm −2 for x = 0.06. Auger recombination, Shockley-Read-Hall recombination and electron leakage are reduced for high In content in the waveguide. Auger carrier loss remains nearly constant above the threshold, hence efficiency droop above the threshold current density is attributed primarily to leakage current density. The efficiency droop for x = 0 is 25.59%, which increased to 36.66% for x = 0.06 at 25 kA cm −2 current density. However, the IQE for x = 0 at 25 kA cm −2 is 0.202, which increased to 0.436 for x = 0.06 at 25 kA cm −2 . Slope efficiency increases with In content; slope efficiency for x = 0.06 improves by 0.2126 W A −1 . Laser output power is improved by 1.91 W at 25 kA cm −2 for x = 0.06.
GaN and AlGaN epitaxial layers are grown by a metalorganic chemical vapour deposition (MOCVD) system. The crystalline quality of these epitaxially grown layers is studied by different characterization techniques. PL measurements indicate band edge emission peak at 363.8 nm and 312 nm for GaN and AlGaN layers respectively. High resolution XRD (HRXRD) peaks show FWHM of 272 and 296 arcsec for the (0 0 0 2) plane of GaN and GaN in GaN/AlGaN respectively. For GaN buffer layer, the Hall mobility is 346 cm 2 /V-s and carrier concentration is 4.5 × 10 16 /cm 3 . AFM studies on GaN buffer layer show a dislocation density of 2 × 10 8 /cm 2 by wet etching in hot phosphoric acid. The refractive indices of GaN buffer layer on sapphire at 633 nm are 2.3544 and 2.1515 for TE and TM modes respectively.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.