Study On The Preparation And The Stabilization Of Porous Silicon

Using the monocrystal silicon wafer chemical etching method, polyslicon flour chemical etching method and the monocrystal silicon double-cell electrochemical etch method to prepare porous silicon. Comparing three methods contrast research, Find that in these three methods, the double-cell electrochemical was easiest to control the technology process, the repeatability of the experiment is good, the performance of porous silicon is the best and the surface of PS is flattest. On basis comparing in first step, we study the proportion of electrolyte, etching time and current density of these three major factors over porous silicon product quality and property. The method and parameters were studied by using scanning electron microscdpe and transmission electron microscope. The orthogonal experimental method is adopted to design anodization parameters. Confirming the best fabricating technology is C_HF=25%, I=60 mA/cm²,T=120min. The productions which could meet the preparation of energy material requirement were gained.In order to solve the problem of PS which is easy to be oxidized, the methods of anodic oxidation and cathode deoxidization which we could use to post-treat porous silicon were adopted; the results indicated that the stability of porous silicon was improved. However, the weight of PS reduced by using the method of cathode deoxidization; the activity of PS is decreased greatly by using the method of anodic oxidation.The porous silicon with high activity after prepared was prost-treated. The result of the study shows that the porous silicon which treated by silane coupling agent keeps high reaction activity and improves the performance of avoiding oxidized in the air. The material with high performance is provided. But the effect of avoiding cracking and spalling by only using silane coupling agent to prost-treat is not good.Complex using anodic oxidation (cathode deoxidization) and silane coupling agent could avoiding cracking and spalling. From the view of avoiding PS's cracking, first using anodic oxidation then using silane coupling agent method is the best method; from the view of keeping high reaction activity of porous silicon, first using cathode deoxidization then using silane coupling agent method is the best.