Micro-Raman Cross-Section Study of Ordered Porous III-V Semiconductor Layers

Porous layers have been obtained by electrochemical etching of n-type III-V semiconductor single crystals (GaAs, InP, and GaP) in water or the ethanol solutions of different acids. The InP porous layers have been shown a more ordered and perfect structure than those of GaP and GaAs. Metal inclusions have been incorporated into the porous layers in an electrochemical cell from an aqueous solution of the Au salt. As found, phonon band intensities are significantly increased in the porous region. The homogeneity of the porous layers prepared has been reliably proved by the Raman micro-spectroscopic mapping of their fresh cleavages. The incorporation of gold into pores leads to a stronger Raman signal of the TO and LO modes, especially in the two-phonon absorption region, and also significantly enhances the photoluminescence of porous layers.