Resonance Raman Spectroscopy of Semiconductors α-HgS and GaP

Resonance Raman scattering in semiconductors αHgS and GaP with indirect and band-gap have been studied with the aid of a dye laser as well as with excitation of discrete wavelengths of argon, Krypton, Yttrium-Aluminum-Garnet, Neodimium, helium-neon and helium-cadmium lasers. It turned out that the resonance in GaP takes place via two mechanisms: very weak indirect gap and more intense direct gap mechanisms. The resonance takes place in αHgS, which differs from GaP in structure; this resonance is a little weaker than the direct gap resonance in GaP. In our opinion, the weak direct transition too contributes to the resonance mechanism. (author)