Abstract
Apparent p‐type conductivity in nonintentionally doped ZnSe layers, grown at high temperature on semi‐insulating GaAs substrates, is investigated by Raman spectroscopy. The microprobe technique provides direct evidence for carrier location on the GaAs side of the structures, close to the interface. Line‐shape analysis of the coupled LO phonon‐plasmon mode for different exciting wavelengths can be achieved, within the model of Hon and Faust [Appl. Phys. 1, 241 (1973)], only when incorporating plasma inhomogeneity. Electronic band bending at the junction in GaAs is deduced from the inferred carrier‐density profile. Changes in Raman spectra under strong illumination are shown to proceed from the flattening of the bands through selective carrier photoinjection.