18 April 2000 Comparative study of near-threshold gain mechanisms in GaN epilayers and GaN/AlGaN separate confinement heterostructures
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Proceedings Volume 3947, In-Plane Semiconductor Lasers IV; (2000) https://doi.org/10.1117/12.382095
Event: Symposium on Integrated Optoelectronics, 2000, San Jose, CA, United States
We report the results of an experimental study on near- threshold gain mechanism in optically pumped GaN epilayers and GaN/AlGaN separate confinement heterostructures (SCHs) over the temperature range of 10 to 300 K. We show that in GaN epilayers the near-threshold gain mechanism is inelastic exciton-exciton scattering for temperatures below approximately 150 K, whereas at elevated temperatures an electron-hole plasma is the dominant gain mechanism. An analysis of the relative shift between the spontaneous emission and lasing peaks in SCH samples, combined with the temperature dependence of the lasing threshold, reveals that exciton-exciton scattering is the dominant gain mechanism leading to low-threshold ultraviolet lasing in the GaN/AlGaN SCH over the entire temperature range studied. Strongly polarized (TE:TM > 300:1) lasing peaks were observed in a wavelength range of 358 - 367 nm. We found that high finesse lasing modes originated from self-formed microcavities in the AlGaN and GaN layers. The lasing threshold was measured to be as low as 15 kW/cm2 at 10 K and 105 kW/cm2 at room temperature. Based on our results we suggest ways for the realization of GaN-active-medium UV laser diodes.
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Sergiy Bidnyk, Sergiy Bidnyk, Jack Biu Lam, Jack Biu Lam, Brian D. Little, Brian D. Little, Gordon Hall Gainer, Gordon Hall Gainer, Yong Hwang Kwon, Yong Hwang Kwon, Jin-Joo Song, Jin-Joo Song, Gary E. Bulman, Gary E. Bulman, Hua-Shuang Kong, Hua-Shuang Kong, } "Comparative study of near-threshold gain mechanisms in GaN epilayers and GaN/AlGaN separate confinement heterostructures", Proc. SPIE 3947, In-Plane Semiconductor Lasers IV, (18 April 2000); doi: 10.1117/12.382095; https://doi.org/10.1117/12.382095


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