Document Type

Article

Original Publication Date

2003

Journal/Book/Conference Title

Journal of Applied Physics

Volume

94

Issue

2

DOI of Original Publication

10.1063/1.1582230

Comments

Originally published at http://dx.doi.org/10.1063/1.1582230

Date of Submission

October 2015

Abstract

We have performed a detailed contactless electroreflectance study of the interband excitonic transitions on both the Ga and N faces of a 200-μm-thick freestanding hydride-vapor-phase-epitaxy grown wurtzite GaN sample with low defect concentration in the temperature range between 20 and 300 K. The transition energies of the A, B, and C excitons and broadening parameters of the A and B excitons have been determined by least-square fits to the first derivative of a Lorentzian line shape. The energy positions and separations of the excitonic transitions in the sample reveal the existence of residual strain. At 20 K the broadening parameter of A exciton deduced for the Ga (5×105 dislocation cm−2) and N (1×107 dislocation cm−2) faces are 3 and 7 meV, respectively, indicating a lower defect concentration on the former face. The parameters that describe the temperature dependence of the interband transition energies of the A, B, and C excitons as well as the broadening function of the A and B features are evaluated. The results from an analysis of the temperature dependence of the broadening function of excitons A and B indicate that GaN exhibits a very large exciton-phonon coupling.

Rights

Huang, Y. S., Pollak, F. H., Park, S. S., et al. Contactless electroreflectance, in the range of 20 K

Is Part Of

VCU Electrical and Computer Engineering Publications

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