Raman study of Ga 1-x Al x N solid solutions
- PDF / 343,316 Bytes
- 8 Pages / 612 x 792 pts (letter) Page_size
- 99 Downloads / 236 Views
Internet Journal of Nitride Semiconductor Research:
Email alerts: Click here Subscriptions: Click here Commercial reprints: Click here Terms of use : Click here
Raman study of Ga1−xAlxN solid solutions F. Demangeot, J. Groenen, J. Frandon, M. A. Renucci, Olivier Briot, S. Ruffenach-Clur and Roger-Louis Aulombard MRS Internet Journal of Nitride Semiconductor Research / Volume 2 / January 1997 DOI: 10.1557/S1092578300001666, Published online: 13 June 2014
Link to this article: http://journals.cambridge.org/abstract_S1092578300001666 How to cite this article: F. Demangeot, J. Groenen, J. Frandon, M. A. Renucci, Olivier Briot, S. Ruffenach-Clur and Roger-Louis Aulombard (1997). Raman study of Ga1−xAlxN solid solutions . MRS Internet Journal of Nitride Semiconductor Research, 2, pp e40 doi:10.1557/ S1092578300001666 Request Permissions : Click here
Downloaded from http://journals.cambridge.org/MIJ, IP address: 141.233.160.21 on 10 Nov 2015
M R S
Internet Journal o f
Nitride S emiconductor Research
Volume 2, Article 40
Raman study of Ga1-xAlxN solid solutions F. Demangeot, J. Groenen, J. Frandon, M. A. Renucci Laboratoire de Physique des Solides de Toulouse, Universite Paul Sabatier Olivier Briot, S. Ruffenach-Clur, Roger-Louis Aulombard Groupe d'Etude des Semiconducteurs, GES-CNRS This article was received on July 18, 1997 and accepted on September 17, 1997.
Abstract Long wavelength optical phonons of Alx Ga1-xN solid solutions have been identified in the whole compositional range by Raman spectroscopy. The frequencies of A1 and E1 polar phonons increase continuously with x from one-member crystal to the other. A generalization of the dielectric model of Hon and Faust is used to treat the coupling of the longitudinal optic (LO) mode. This approach accounts for the observed frequencies and confirms the so-called one-mode behaviour of polar LO phonons. Moreover,a signature of the coupling of a discrete mode (tentatively associated to silent q=0 B1 mode) with an unidentified continuum has been obtained.
1. Introduction Gallium-aluminium nitride alloys may be promising materials for optical applications, particularly for light emission in the ultraviolet range. Indeed, the forbidden band of these wide gap semiconductor alloys seems to be suitable to many applications in this spectral range. Moreover, the residual deformation in these layers, due to the lattice mismatch with the substrate (generally sapphire), may be changed by the aluminium content of the alloy. Basic studies on these ternary solid solutions were recently developed. The literature concerning Raman spectra from Ga1-XAlXN crystals is poor: we note only the paper published by Hayashi et al. [1],who found a one-mode behaviour for the polar phonons in a very small compositional range (x≤0.15). In this communication, we present a report on the dynamical properties of Ga1-XAlXN crystals (00.5,the intensity of Raman spectra decreases and the peaks become broader and broader. Moreover, we observe for x>0.7 a complete relaxation of selection rules, probab
Data Loading...
