Study of -doped GaAs layers by micro-Raman spectroscopy on bevelled samples

Abstract Si -doped GaAs layers were studied by micro-Raman spectroscopy. The spectra were recorded along the bevelled structure using the light of Ar + ion laser (514.5 nm line) with high power density. The observed changes in the Raman spectra are discussed in the sense of coupling present between LO phonon and photoexcited electron-hole plasma and plasma of electrons arising from ionized Si atoms. PLP modes of the coupling of photoexcited plasma in -doped GaAs layers were observed for the first time. The minimal thickness of cap layer was estimated in the range of 10÷19 nm depending on the doping concentration