Study Of Porous Silicon Anti-reflection Layer Prepared By Electrochemical Method

Since the birth of the world’s first porous silicon and its first used for solar cell anti-reflective materials, the methods of preparation and application of porous silicon have progressed a lot, but how to obtain more uniform porous silicon and how to decrease its reflection, extend its minority carrier life time, increase compatibility with other processing of solar cell need more research.The characteristic and optical property of porous silicon under different electrochemical method and conditions are diverse, even though it is prepared by on the same doping type and concentration of monocrystalline wafer.It’s very important for its wide application to research electrochemical methods and conditions of porous silicon.In this paper, the influence of current density, etching time and concentration of hydrofluoric acid on optical property and microstructure of porous silicon were researched.Atomic Force Microscope (AFM) and Fourier Transform Infrared Spectroscopy (FTIR) were used to represent optical property and microstructure of porous silicon.The results showed that(1) Researched how to avid the peel of carbon atoms during the preparation of porous silicon by electrochemical method using graphite electrode as cathode;(2) Determined etching time range for subsequent experiments by carrying out the influence to microstructure of porous silicon from etching time under has initially identified the current density and concentration of hydrofluoric acid;(3) Researched the influence to microstructure of porous silicon from the change of current density and concentration of hydrofluoric acid, and joined these etching parameters with the number of particles on the suferce of porous silicon;(4) Determined etching parameters for the preparation of anti-reflective porous silicon through electrochemical method by using FTIR to test the samples-anti-reflection.Optical property and microstructure of porous silicon rely on conditions of electrochemical etching, so the best parameters in this paper may be not suitable for other experiments.