Resonance Raman Spectroscopy of Mn-Mgk Cation Complexes in GaN

Crystals

Alberta Bonanni¹  Dmytro Kysylychyn¹  Giulia Capuzzo¹  Andrii Nikolenko²  Viktor Strelchuk²  Bogdan Tsykaniuk² 

[1] Institut für Halbleiter-und-Festkörperphysik, Johannes Kepler University, Altenbergerstr. 69, A-4040 Linz, Austria;V. Lashkaryov Institute of Semiconductor Physics of National Academy of Sciences of Ukraine, 41 Nauky pr., 03028 Kyiv, Ukraine;

关键词: metal-organic vapor phase epitaxy;    III-nitrides;    cation complexes;    resonance Raman spectroscopy;    electron-phonon interaction;   

DOI  :  10.3390/cryst9050235

来源: DOAJ

【 摘 要 】

Resonance Raman analysis is performed in order to gain insight into the nature of impurity-induced Raman features in GaN:(Mn,Mg) hosting Mn-Mg_k cation complexes and representing a prospective strategic material for the realization of full-nitride photonic devices emitting in the infra-red. It is found that in contrast to the case of GaN:Mn, the resonance enhancement of Mn-induced modes at sub-band excitation in Mg co-doped samples is not observed at an excitation of 2.4 eV, but shifts to lower energies, an effect explained by a resonance process involving photoionization of a hole from the donor level of Mn to the valence band of GaN. Selective excitation within the resonance Raman conditions allows the structure of the main Mn-induced phonon band at ~670 cm⁻¹ to be resolved into two distinct components, whose relative intensity varies with the Mg/Mn ratio and correlates with the concentration of different Mn-Mg_k cation complexes. Moreover, from the relative intensity of the 2LO and 1LO Raman resonances at inter-band excitation energy, the Huang-Rhys parameter has been estimated and, consequently, the strength of the electron-phonon interaction, which is found to increase linearly with the Mg/Mn ratio. Selective temperature-dependent enhancement of the high-order multiphonon peaks is due to variation in resonance conditions of exciton-mediated outgoing resonance Raman scattering by detuning the band gap.

【 授权许可】

Unknown