Preparation and Raman scattering study of pore arrays on an InP(100) surface

Straight nanometer-sized pore arrays are formed on an n-InP (1 0 0) surface by electrochemical anodization in HCl-based electrolytes. Raman scattering spectra are measured and compared to those of the bulk InP. Two new peaks around 299 and 304 cm(-1) are observed for porous InP. The peak at 299 cm(- 1) is attributed to a TO phonon mode observable due to a breakdown of polar ization selection rule in the case of nanometer-sized crystallites. The pea k at 304 cm(-1) is suggested to be a surface-related vibration mode. In add ition, the Raman signals of the porous InP are intensified up to 20-25 time s than that of the bulk InP. The reason for such strong enhancement is not clear and is under further investigation. (C) 2001 Elsevier Science B.V. Al l rights reserved.