Picture of a sphere with binary code

Making Strathclyde research discoverable to the world...

The Strathprints institutional repository is a digital archive of University of Strathclyde research outputs. It exposes Strathclyde's world leading Open Access research to many of the world's leading resource discovery tools, and from there onto the screens of researchers around the world.

Explore Strathclyde Open Access research content

Exciton localization and quantum efficiency - a comparative cathodoluminescence study of (In, Ga)N/GaN and GaN(Al,Ga)N quantum wells

Watson, I.M. and Jahn, U. and Dahr, S. and Brandt, O. and Grahn, H.T. and Ploog, K.H. (2003) Exciton localization and quantum efficiency - a comparative cathodoluminescence study of (In, Ga)N/GaN and GaN(Al,Ga)N quantum wells. Journal of Applied Physics, 93 (2). pp. 1048-1053. ISSN 0021-8979

Full text not available in this repository. (Request a copy from the Strathclyde author)

Abstract

We study the quantum efficiency () and transition energy (Et) as a function of excitation density and temperature in (In,Ga)N/GaN multiple quantum wells (MQWs) fabricated by molecular-beam epitaxy (MBE) and metal-organic chemical-vapor deposition (MOCVD), as well as in an MBE-grown GaN/(Al,Ga)N MQW. A method based on cathodoluminescence spectroscopy is proposed to be suitable for a reproducible measurement of the power dependence of and Et. The experimental results are fit to a recently developed model allowing for a distinction of localization and electric-field effects for and Et, as well as for the extraction of the localization energy, density of localization centers, and radiative recombination rate of localized excitons. In the (In,Ga)N/GaN MQWs grown by MBE and MOCVD, we found a value of the localization energy of 34 and 100 meV, respectively. In the MBE-grown GaN/(Al,Ga)N MQW, the exciton recombination is dominated by quasifree excitons even at low temperatures.