RAMAN-SPECTRA OF GE0.11SI0.89 STRAINED QUANTUM WIRES

We have calculated the Raman spectrum of strained Ge0.11Si0.89 wires s andwiched between Si layers. Because of the relatively large width and penetration depth of the laser beam the volume sampled by the beam is large. Using the strain components calculated by the finite element m ethod, the strain induced Raman shifts and Raman spectra were calculat ed at each point in the volume sampled. The final spectrum obtained by superposing these spectra shows excellent agreement with the observed spectrum. The strain induced shift measured by micro Raman in nonunif ormly strained solids does not give strain values in a straightforward manner.