The lattice vibrational properties of new semiconductor alloys, GaAs1-xBix
and InAs1-xBix, are reported. These alloys, which were grown by metalorgani
c vapor phase epitaxy technique, contain a small amount (1.2%-3.8%) of Bi.
A detail Raman scattering study of these new alloys, which exhibit weak tem
perature dependence of the band gap with increasing amount of Bi, is report
ed here. Good crystalline quality and spatial homogeneity was confirmed usi
ng micro-Raman technique. The alloys show ternary compound behavior, confir
ming substitutional incorporation of Bi into the lattice site. New vibratio
nal modes observed were assigned to GaBi-like and InBi-like modes. In addit
ion, phonon-plasmon coupled modes and vibrational modes corresponding to Bi
and As materials were also observed. Results are discussed to characterize
these new alloys in detail. (C) 2001 American Institute of Physics.