Nanoscale Characterisation of Exciton and Carrier Diffusion in Wide Band Gap Semiconductors using Low Voltage Cathodoluminescence Microscopy and Spectroscopy
|Matthew R. Phillips 1, Dominique Drouin 2|
1. University of Technology (UTS), PO Box 123, Broadway, NSW 2007, Sydney, Australia
A modern Schottky field emission scanning electron microscope is capable of injecting electron hole pairs into sub-10nm volumes when operating at low voltage (< 1 kV). Under these conditions the electron probe can generally be considered to be purely diffusive and consequently carrier behaviour can be investigated using scanning cathodoluminescence microscopy and spectroscopy at high spatial resolution. In this paper, the utility of low voltage scanning cathodoluminescence will be demonstrated by presenting temperature resolved studies of carrier and exciton diffusion in technologically important materials that exhibit short recombination lengths, such as Gallium Nitride and Zinc Oxide. Factors that determine the free exciton lifetime in these materials and the impact of the surface on these cathodoluminescence measurements will also be discussed.
Presentation: Oral at E-MRS Fall Meeting 2007, Symposium J, by Matthew R. Phillips
See On-line Journal of E-MRS Fall Meeting 2007
Submitted: 2007-05-14 16:45 Revised: 2009-06-07 00:44