Pulse- and field-resolved THz-diagnostics at 4<i/> ^{t h} generation lightsources

Raman spectral shift versus strain and composition in GeSn layers with 6%–15% Sn content

“…As expected, a clear red shift is observed as the Sn content in those layers increases from 6% up to 15%. [42][43][44][45][46][47][48] bandgap is evaluated to be around 0.45eV 12 and the pseudomorphic bandgap around 0.55 eV 28 . We clearly see that the spectrum associated with the pseudomorphic layer (i.e the 30 nm thick one) is centered on the strained value (0.55eV) while the spectrum of the partially relaxed layer (i.e with 480 nm) is centered on the relaxed bandgap value (0.45eV).…”