Resonant Raman Scattering in GaAs_1-xP_x:N

We report a study of the resonant Raman scattering (RRS) by optical phonons that is induced by excitons bound to isoelectronic nitrogen impurities in GaAs_1-xP_x:N alloys. Under resonant excitation into N_x band, strong Raman lines involving allowed LO and “forbidden” TO for backscattering configuration from (100) surface are observed. This is interpreted as the breakdown of normal selection rule in the RRS process. By following the temperature dependence of the N_x luminescence and its phonon sidebands, we also separate RRS from sharp line due to luminescence.