Resonant Raman Scattering and Luminescence in Indium Iodide

抄録

Resonant Raman effect of InI is investigated at 2.2 K by tuning a cw dye laser. Scattering spectra under the resonant excitation around the first exciton band consist of Raman lines which shift with the exciting laser energy, and of ordinary luminescence bands which do not shift in photon energy. Raman lines are composed of five Raman-active lines, forbidden 1LO (13.8 meV) and its overtone (27.5 meV). Two lines (7.00 meV and 10.7 meV) of five Raman-active lines are assigned as A_g symmetry. Resonant enhancement in the scattering intensities occurs in the 1LO, the 2LO and two A_g lines of five Raman-active lines. It is confirmed that the forbidden 1LO intensity shows steep enhancement in resonance with both bound and free excitons, whereas the 2LO intensity increases more gradually as the incident photon energy approaches to the free exciton energy.