Intraband absorption of doped GaN∕AlN quantum dots at telecommunication wavelengths

Abstract

We report the Stranski–Krastanov growth of Si-doped GaN∕AlN quantum dot superlattices displaying conduction-band interlevel absorption at telecommunication wavelengths. By adjusting the growth conditions, quantum dots with a height of 0.5–1 nm in the density range of 0.1×1012–3×1012cm−2 can be synthesized. All of the samples exhibit room-temperature interlevel absorptions in the 1.41–1.54μm wavelength range. The full width at half maximum of the observed intraband absorptions is as small as 88 meV. We also observe residual intraband absorption for nominally undoped samples. We attribute this effect to the detrapping of electrons in the AlN barriers and subsequent capture in the dots.