Intrinsic electric fields and Raman spectra of III-V nitride wurtzite semiconductor heterostructures

The analysis of Raman data on semiconductor nitride heterostructures is complicated by large intrinsic electric fields. This issue is analyzed here by calculating the Raman signal for quantum wells made from wurtzite AlN-GaN. The signature of the confined phonon modes in GaN quantum wells is calculated and found to be strongly effected by the intrinsic electric fields due to lattice mismatch and the piezoelectric character of the materials. This calculation suggests that the effects of electric fields on the electronic states in III-V nitride heterostructures should be taken into account in the analysis of Raman spectra in these materials and that the application of realizable external electric fields would be a useful probe of these materials.