Raman spectroscopy study on order-disordered Ga/sub 0.52/In/sub 0.48/P on GaAs grown by MOVPE

摘要

We report the first observation of single particle excitation (SPE) in electronic Raman spectroscopy as well as the plasmon related Raman peak located at 352 cm/sup -1/ in the ordered Ga/sub 0.52/In/sub 0.48/P:Se with a carrier concentration of <10/sup 17/ cm/sup -3/. These observations indicate that high density thermally excited carriers exist in the ordered Ga/sub 0.52/In/sub 0.48/P:Se. However, the disordered Ga/sub 0.52/In/sub 0.48/P:Se with almost same amount of carrier concentration does not show either SPE or plasmon related peaks. This implies that the ordering might cause a carrier confinement effect to increase the density of carriers. This confinement effect could be possible if the ordered region with a lower bandgap energy is surrounded by the disordered matrix with a higher bandgap energy in the ordered Ga/sub 0.52/In/sub 0.48/P.