Resonant Raman scattering in GaN/Al0.15Ga0.85N and InyGa1-yN/GaN/AlxGa1-xN heterostructures

We report on resonant Raman scattering in Al0.15Ga0.85N/GaN single quantum wells (QWs) and AlxGa1-xN/GaN/InyGa1-yN heterostructures. By choosing appropriate excitation conditions we could probe selectively the GaN quantum well or the Al0.15Ga0.85N barrier of Al0.15Ga0.85N/GaN single quantum wells. For the InxGa1-xN material system a linear frequency shift of the E-2- and A(1)(LO) phonon mode to lower frequencies was found with increasing in content. The shift was determined to -0.79cm(-1) per % in content for the A(1)(LO) phonon frequency. Resonant excitation of AlxGa1-xN/GaN/InyGa1-YN heterostructures enabled us to detect phonon signals from the InxGa1-xN layer in the heterostructure and to determine its ln content.