Radiation enhancement in doped AlGaN-structures upon optical pumping

Spectral characteristics of spontaneous and stimulated luminescence have been studied for molecular beam epitaxy synthesized Al$_{x}$Ga$_{1-x}$N/AlN solid solutions with $x$ = 0.5 and 0.74 upon optical pumping by pulse laser radiation with $\lambda$ = 266 nm. Broadband radiation spectra with a width of $\sim$260 THz for Al$_{0.5}$Ga$_{0.5}$N and $\sim$360 THz for Al$_{0.74}$Ga$_{0.26}$N have been obtained. The measured enhancement factors are $g\approx$ 70 cm$^{-1}$ for Al$_{0.5}$Ga$_{0.5}$N at $\lambda\approx$ 528 nm and $g\approx$ 20 cm–1 for Al$_{0.74}$Ga$_{0.26}$N at $\lambda\approx$ 468 nm.