Abstract
A detailed photoluminescence (PL), time-resolved photoluminescence (TRPL), and photoreflectance (PR) analysis of AlGaN/GaN heterostructures grown on sapphire is presented in this paper. We have examined a number of samples in which the thicknesses of the Al0.3Ga0.7N layers vary from 18 to 75 nm. Room temperature PL under pulsed 266 nm excitation allowed for determination of the Al content in the examined thin AlGaN layers. Time-resolved PL measured at 1.6K exposed huge difference in the emission dynamics for different Al0.3Ga0.7N layer thickness. We observed an enormous increase of the emission decay above the critical thickness of the AlGaN layer. PR spectra (associated with the GaN main layer) measured on AlGaN/GaN systems are discussed in terms of the thickness of the capping layer. Photoreflectance analysis of the AlGaN/GaN interface showed that the phase of the signal shifts as the Al0.3Ga0.7N layer increases its thickness. These phase shifts of the PR signals related to GaN are interpreted in terms of optical interference effect in the AlGaN capping layer. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
