Fabrication and Characteristics of Porous Silicon for Photoconversion
Dr. Uday M. Nayef

Porous silicon (PS) layers are prepared by anodization for etching time densities. The samples are then characterized the nanocrystalline porous silicon layer by X-Ray Diffraction (XRD), Atomic Force Microscopy (AFM), Fourier Transform Infrared (FTIR), Raman and electrical properties. PS layers were formed on a p-type Si wafer. Anodized electrically with a 10, 20 and 40 min etching times for fixed 20 mA/cm2 current density. We have estimated crystallites size from X-Ray diffraction about nanoscale for porous silicon and AFM confirms the nanometric size and therefore optical properties about nanocrystalline silicon yields a Raman spectrum showing a broadened peak shifted below 520 cm-1. The electrical properties of prepared PS; namely current density-voltage (J-V) characteristics under dark, and illuminations show that the pass current through the PS layer decreased by increasing the etching time, due to increase the resistivity of PS layer. The photosensitivity measurements of prepared PS layer showed the peak value in visible region at (400-600 nm) increased with increasing the etching time. Web Site:  http://www.ijens.org/IJBAS%20Vol%2013%20Issue%2002.html