The Impact of Doping on the Anti-Resonance Effects of A11g Mode of InSe

A comparative study of anti-resonance effects in InSe and InSe doped with GaS, using the resonant Raman spectroscopy is presented. The nonpolar optical phonon of symmetry in InSe exhibits a pronounced decrease in the Raman cross-section at excitation energy 2.585 eV. In InSe doped with GaS samples, it is found that the anti-resonance behavior decreases as doping contents are increased. To account these observations, a model is applied to explain and interpret the Raman intensity evolution versus incident photon energy. The agreement between theory and experiment is good.