Measurements of elastic constants of wide Al-composition range AlGaN epi-materials from metalorganic chemical vapor deposition

Brillouin scattering measurements and investigation on AlGaN alloy films with Al compositions of 00.62 from metalorganic chemical vapor deposition are performed. Six elastic constants and bulk modulus of a wide Al-composition range of AlGaN epi-materials are deduced. It is revealed that the elastic constant values of ternary AlGaN with Al compositions of 0.20–0.62 are much greater than those of binary GaN and AlN. It is indicated that the addition of Al in GaN or Ga in AlN has caused a rise in the bulk modulus. The graphical variations and formalized polynomial descriptions of elastic constants and bulk modulus vs Al composition in the full Al range are presented. Brillouin scattering studies on AlGaN alloys address a previously unexplored research gap in wide-bandgap AlGaN semiconductors, as no such studies have been reported so far to the best of our available knowledge. This research and the detailed experimental and calculated data may provide a foundation for more in-depth scientific analyses and future investigations.