Studying the wetting agent impact in the porous silicon production

Abstract

Newly, porous silicon (PS) powder has been developed to meet the requirements of various fields due to its unique physical and chemical properties. In this research, the PS powder is produced using a combination of both (alkali chemical etching and ultra-sonication techniques) from commercial polycrystalline silicon powder. It shows the dependence of the crystal structure and the morphology on the value of wetting agent concentration, which is controlled on the rate of each chemical reaction in the formation process. For the first time, the PS pines shape is a product at using the preparation conditions (7 wt %KOH, 3 hours, and 15 Vol% NPA). On the other hand, the (PS) micro-rod clusters are produced with different values of both the diameter and the pore size at wetting agent concentrations variation (20, and 25 Vol% NPA). The most stable crystal structure of silicon surface is Si (111), it has a rhombohedral unit cell. By changing the wetting agent concentration value, then the crystal structure of the product powder is changed too, from rhombohedral plane Si (111) to the hexagonal plane Si (211). So, this increases the chances of using the PS product in many fields whether medical or engineering.