Stokes and anti-Stokes resonant Raman scatterings from biased GaN/AlN heterostructure

An electric field present in a GaN/AlN heterostructure can bring both the first-order and second-order Raman scattering processes into strong resonances. The resonant Stokes and anti-Stokes Raman scatterings result in the increase and decrease in nonequilibrium longitudinal-optical phonon temperatures, respectively. Moreover, the phonon temperature measured from the Raman scattering is increased with an applied electric field at a much higher rate than the lattice temperature due to the presence of field-induced nonequilibrium longitudinal-optical phonons.