The study of near-resonance Raman scattering of AlInN/AlN/GaN heterostructure

• The near-resonance Raman scattering of AlInN/AlN/GaN heterostructure happens under the UV light (325 nm) excitation.
• Interface-related phonon modes in this structure are observed due to the resonance enhanced effect.
• The theoretical results of interface phonon modes are consistent with the experimental results.

The visible and ultraviolet (UV) Raman scattering of an AlInN/AlN/GaN heterostructure were measured under z(x,_)z¯ configuration at room temperature. Compared with the visible Raman spectrum, three new peaks at 609, 700, and 840 cm−1 occurred in the UV Raman spectrum and were verified to result from the resonance enhanced Raman effect. The near-resonance Raman scattering is stimulated by the electron transition process between the valence band and subband of triangular quantum well located at the interface of AlN/GaN because this transition process has a near equal energy with the 325 nm excitation light. According to the calculated dispersion relations of interface phonon modes in the AlInN/AlN/GaN heterostructure and the 2DEG-related resonance enhanced effect, these new Raman peaks were mainly attributed to the interface phonon modes and disorder-activated mode. The contributions from the bulk phonon modes of AlN and AlInN layers play a very minor role.