We have studied the structural and optical properties of InxAl1-xN alloys with compositions nearly lattice-matched to GaN. Scanning electron microscopy measurements reveals a good overall surface quality, with some defect structures distributed across the surface whose density increases with the InN concentration. On the other hand, Raman scattering experiments show three peaks in the frequency range between 500 and 900 cm which have been assigned to InN-like and AIN-like E-2 modes and A(1)(LO) mode of the InxAl1-xN. These results agree with theoretical calculations previously reported where two-mode and one-mode behavior was predicted for the E-2 and A(1)(LO) modes, respectively. Photoluminescence and photoluminescence excitation allowed us to determine the emission and absorption energies of the InxAl1-xN epilayers. Both energies display a redshift as the InN fraction increases. We find a roughly linear increase of the Stokes shift with InN fraction, with Stokes shift values of approximate to 0.5 eV in the composition range close to the lattice-matched condition.
|Other||Symposium on GaN, AIN, InN Related Materials|
|Period||28/11/05 → 2/12/05|
- MOCVD InAlN epilayers
- InxAl1-xN alloys
- raman scattering