基于法布里-珀罗效应的纳米有序多孔硅光学传感器研究

Study on optical sensor based on Fabry-Perot effect of nanometer orderly porous silicon

利用电化学方法在N型0.01Ω·cm单晶抛光硅片上制备纳米有序多孔硅,研究电流密度对其形貌及光学性能的影响;并通过对硅基体进行预处理达到消除多孔硅表面小孔硅的目的.结果表明,随着电流密度的增大,多孔硅的孔径、孔隙率以及光学厚度均增大.给经过预处理的硅基体施加75 m A/cm2的电流密度,多孔硅的表面孔径达到50 nm,与体孔径大小一致;在光学检测中对酒精溶液表现出良好的敏感性,检测浓度能够低至5×10-5 mol/L.

In this work, we obtained the nanometer orderly porous silicon in n-type orientation silicon wafer with a resistivity of 0.01 Ω·cm by using electrochemical etching. The influence of applied current density for porous silicon mierostrueture and optical property was investigated. Before fabricating porous silicon, we gave silicon substrate some preliminary treatment in order to remove the tiny pore in the silicon surface. With the increase of current density, pore diameter, porosity and optical thickness of porous silicon were increased. The surface diameter of porous silicon can reach 50 nm, which was consistent with the inner pore size, when applied the current density was 75 mA/cm2 on the pre-treatment silicon substrate. This sample had well sensing property for ethanol solution using optical detection, and the detectable level could below to 5× 10-5 mol/L.