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RESEARCH PRODUCT
Resonant Raman characterization of InAlGaN/GaN heterostructures
Martin KuballAndrés CantareroAna CrosJames W PomeroyNikos T. PelekanosAlexandros Georgakilassubject
Materials scienceCondensed matter physicsBand gapPhononAnalytical chemistryHeterojunctionCondensed Matter PhysicsElectronic Optical and Magnetic MaterialsCondensed Matter::Materials Sciencesymbols.namesakeAbsorption edgeExcited statesymbolsElectronic band structureRaman spectroscopyRaman scatteringdescription
InAlGaN/GaN heterostructures and thin films with In composition ranging from 0.03 to 0.1 are characterized by means of Raman scattering excited at various energies in the ultra violet range, tuning the laser excitation energy through the band gap of In x Al y Ga 1-x-y N. It is shown that the addition of In to the Al y Ga 1-y N alloy diminishes considerably the vibration energy of the A 1 (LO) phonon mode. The phonon line is asymmetric on the low energy side, and the asymmetry increases with In content, while the main peak shifts to lower energies. A shift of the phonon energy has also been observed when the excitation energy is close to the absorption edge of the In x Al y Ga 1-x-y N layer. The nature of this shift is discussed in relation with intrinsic and extrinsic inhomogeneities in the quaternary alloy.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2006-06-01 | physica status solidi (b) |