ABSTRACT

Real electronic states within the bandgap have been investigated for two different CuGaSe2 crystals by enhancement in resonant Raman scattering (RRS). On one crystal, a broad peak centered at 1.58 eV by photoluminescence (PL) measurement is also observed at 1.58–1.59 eV by RRS. On the other crystal, however, three peaks located at 1.64, 1.67 and 1.70 eV are found by RRS measurement, whereas only one peak at 1.62 eV exists in PL spectra. It is found that real electronic states can be examined in more detail by RRS measurement than by usual PL measurement.