Strain related relaxation of the GaAs-like Raman mode selection rules in hydrogenated GaAs1-xNx layers
| Autor: | Giorgio Pettinari, Maddalena Patrini, Mario Capizzi, Antonio Polimeni, Giorgio Guizzetti, Marco Felici, M. S. Sharma, Silvia Rubini, E. Giulotto, M. Geddo |
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| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
congenital
hereditary and neonatal diseases and abnormalities Materials science Phonon General Physics and Astronomy 02 engineering and technology Epitaxy 01 natural sciences Gallium arsenide chemistry.chemical_compound symbols.namesake strain 0103 physical sciences Raman 010302 applied physics Condensed matter physics Strain (chemistry) Scattering Relaxation (NMR) nutritional and metabolic diseases 021001 nanoscience & nanotechnology Blueshift dilute nitride chemistry hydrogen symbols 0210 nano-technology Raman spectroscopy |
| Zdroj: | Journal of applied physics 125 (2019). doi:10.1063/1.5093809 info:cnr-pdr/source/autori:Giulotto, E.; Geddo, M.; Patrini, M.; Guizzetti, G.; Sharma, M. S.; Capizzi, M.; Polimeni, A.; Pettinari, G.; Rubini, S.; Felici, M./titolo:Strain related relaxation of the GaAs-like Raman mode selection rules in hydrogenated GaAs1-x<%2Finf>Nx<%2Finf> layers/doi:10.1063%2F1.5093809/rivista:Journal of applied physics/anno:2019/pagina_da:/pagina_a:/intervallo_pagine:/volume:125 |
| DOI: | 10.1063/1.5093809 |
| Popis: | The GaAs-like longitudinal-optical (LO) phonon frequency in hydrogenated GaAsN (x = 0.01) layers - with different H doses and similar low-energy irradiation conditions - was investigated by micro-Raman measurements in different scattering geometries and compared with those of epitaxial GaAs and as-grown GaAsN reference samples. A relaxation of the GaAs selection rules was observed, to be explained mainly on the basis of the biaxial strain affecting the layers. The evolution of the LO phonon frequency with increasing hydrogen dose was found to heavily depend on light polarization, thus suggesting that a linear relation between strain and the frequency of the GaAs-like LO phonon mode should be applied with some caution. Moreover, photoreflectance measurements in fully passivated samples of identical N concentration show that the blueshift of the GaAs-like LO frequency, characteristic of the hydrogenated structures, is dose-dependent and strictly related to the strain induced by the specific type of the dominant N-H complexes. A comparison of photoreflectance results with the finite element method calculations confirms that this dependence on the H dose is due to the gradual replacement of the N-2H complexes responsible for the electronic passivation of N with N-3H complexes, which are well known to induce an additional and sizeable lattice expansion. |
| Databáze: | OpenAIRE |
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