Morphology and Optical Properties of Nanostructure Porous Silicon Prepared by Electrochemical Etching for Solar Cells Application

In this work, nanostructure porous silicon surface was prepared using electrochemical etching under different current densities. I have studied the surface morphology and photoluminsense of four samples prepared at current densities 5, 10, 15 and 20 mA/cm(2) at fixed etching time 10 min.photoluminsense study showed that the energy gap of the porous silicon samples are is 3.1eV,and it was higher than the energy gap of bulk silicon which was 1.08 eV. A scanning electron microscope (SEM) micrographs were used to estimate the surface area. The surface area of the porous layer is strongly dependent on the porous layer geometry and its depth. The optical reflectance measurements were obtained by using an optical reflectometer (UV) which is equipped with an integrating sphere in the (200-1100)nm wavelength range, which reveals that the textured cells with PS layer sources have lower reflectivity value compared to the textured cell without PS structure.