Event Details

Cathodoluminescence of III-nitride semiconductor nanostructures and devices

Abstract: Scanning electron microscopes (SEMs) provide a means to study materials, such as light-emitting semiconductors, with a spatial resolution in nanometre. This talk will consider what can be added to straight-forward SEM imaging, analogous to the saying "you know you're getting old when you stoop to tie your shoe-laces and wonder what else you could do while you're down there''. It will describe aspects of using cathodoluminescence (CL) spectroscopy and spectral mapping to understand and develop a range of III-nitride semiconductor structures and will then discuss what else can usefully be brought in "while you're down there''. It will discuss the use of complementary techniques such as wavelength and energy dispersive X-ray (WDX/EDX), electron beam induced conductivity (EBIC), electron channelling contrast imaging (ECCI) and electroluminescence (EL). Structures studied will include InGaN and AlGaN-based core-shell nanorod arrays produced by colleagues at the University of Bath and the Technische Universität Berlin as well as semi- and non-polar orientated III-nitride layers fabricated at the University of Sheffield. The ability of CL to provide highly resolved measurements, at wavelengths down to \(200\,\mathrm{nm}\) and also in a low-vacuum environment, assists in the development and deployment of the III-nitrides materials. The complementary techniques enable the light emitting properties to be correlated with the nanostructure, material composition and the density and type of dislocations and defects.