Patel, B K; Mythili, R; Vijayalaxmi, R; Soni, R K; Behera, S N; Sahu, S N
Porous Si; Etching; Raman scattering
In situ current (I)–(V) voltage studies were carried out to get a better understanding of the mechanism of formation of porous silicon (PS). It is observed that on decreasing the anodization current density below a critical value (75 mAcm−2) the size of the PS crystallites increases while for its values above 75 mAcm−2 electropolishing occurs. Raman spectroscopic studies show that the sizes of the Si crystallites are small and change from 4.7 to 3.8 nm when the current densities are increased from 20 to 50 mAcm−2. Transmission electron micrographs show preferential propagation of pores whereas transmission electron diffraction (TED) patterns show typical crystalline Si with the cubic structure.