Room temperature photoreflectance of different electron concentration GaN epitaxial layers

Photoreflectance investigations of AlGaN/GaN heterostructures with a two dimensional electron gas

“…Features labeled A, B, and C are related to the [20], respectively. The character of these transitions for a high quality GaN layer, such as the sample SR, is mainly excitonic [21,22] due to the high exciton binding energy, ∼26 meV. In the case of PR obtained for HFET structures, transitions originating from both GaN and AlGaN layers are very well visible.…”

Study of the activation process of Mg dopant in GaN:Mg layers

“…We have observed that the broadening of the bandgap-related peak is not influenced by the increase in Mg concentration, and the broadening is ~45 meV for each sample. Such broadening is typical for high quality GaN layers [10], and indicates that the incorporation of Mg atoms does not deteriorate the structural quality of the sample.…”

Photoreflectance study of p-type GaN layers

“…In the case of the reference sample SR, we have observed PR features typical for nominally undoped GaN layers, i.e. n-type GaN [10,11,13]. The features labeled A, B, and C are related to the [20], respectively.…”

“…The features labeled A, B, and C are related to the [20], respectively. The character of these transitions for a high quality GaN layer, such as the sample SR, is mainly excitonic [11,13] due to the high exciton binding energy ∼26 meV. In the case of GaN:Mg layers the PR spectra are completely different from the PR spectrum obtained for the reference sample SR.…”

“…Photoreflectance (PR) spectroscopy is such a technique [6][7][8]. So far, PR spectroscopy has been many times applied to investigate GaN-based structures [9][10][11][12][13][14][15][16][17][18][19]. In this paper, we have applied PR spectroscopy to investigate p-type GaN layers for the first time.…”