Abstract
Raman images (30μm⨉30μm⨉180μm) of E2 of a bulk GaN have been measured by Micro-Raman Spectroscopy from room-temperature up to 300°C. The average values of center frequency of E2 mode (579 cm−1) over the imaging area shows the variation of decrease gradually and linewidth increases slowly with increasing temperature (Fig.1). We have evaluated temperature dependence of the line broadening of E2 mode in GaN in high temperature region by phonon dispersions with a band-gap ~ 180 cm−1 by Ab-initio calculations. As a result, experimental values of linewidth have been reproduced by calculated ones due to cubic term.
© 2018 The Author(s)
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