Abstract
Photomodulation Raman spectroscopy (PM-RS) has been employed to investigate the effect of the interfacial minority carrier traps in metal: n-type GaAs interfaces; using the forbidden LO phonon scattering as a prob. Photomodulating-pumping beam (PMB) will decrease the interfacial field and consequently the intensity of forbidden LO scattering. Two molecular beam epitaxy junctions of 80 A degrees Au on n-type GaAs (001) substrate with two different doping densities were used. The change in the band bending has been obtained as a function of the photomodulating intensity for the low doping case. The minority carrier's lifetime was also determined through dynamical measurements for the PM-RS intensity.