SiO_2微球模板制备多孔硅与其热电性能研究

Preparation and Thermoelectric Property Study of Porous Silicon Covered SiO_2 Nanospheres Template

利用SiO_2微球模板法腐蚀Si片,发现不仅提高了腐蚀速率,而且孔洞更加均匀,孔隙率和有序性有所提高.对所制备的多孔硅进行性能测试结果表明,随腐蚀时间增加热导率降低.与相同时间无模板直接化学腐蚀多孔硅相比,SiO_2微球模板法得到的多孔硅有更低的热导率.将多孔硅腐蚀时间75min与腐蚀时间90min进行比较,样品的激活能由100.49meV增加到174.19meV,电阻率略有上升.

The silicon that covered SiO2 nanospheres template was etched through the electrochemical corrosion method.The obtained samples with relatively homogeneous and ordered pores,and the corrosion rate is faster and porosity is higher than that without covered SiO2 template.The property of thermal conductivity was measured and analysised.The thermal conductivity is obviously decreased with the increasing of etching time.The thermal conductivity of the obtained samples is lower than that without covered SiO2 template.A comparison of the two samples of etching 75 min and 90 min by using the template indicates that the thermal activation energy increases from 100.49 meV to 174.19 meV,which makes the resistivity of the sample increase slightly.