Analysis of Nanocrystal of Porous Silicon with High-Resolution Transmission Electron Microscopy

The porous silicon samples were prepared with n(111) Si wafers by electrochemical polarization and their microstructures were characterized by high-resolution transmission electron microscopy (HRTEM). The DigitalMicrograph image processing was used to analyze the HRTEM images. The distorted Si (111) crystal plane was observed on porous silicon and could be distinguished with the Fourier transforming electron diffraction (ED) pattern. Grain boundaries were presented in the HRTEM images where the lattice fringes distortions took place. The anisotropy property could be preserved at a small location area because of the smaller nanocrystals in different directions appeared amorphous in the ED pattern at a larger range.