基于微拉曼光谱技术的氧化介孔硅热导率研究

利用基于有效介质理论的介孔硅传热机理，提出一个用于分析氧化介孔硅热导率的理论模型，对影响氧化介孔硅有效热导率的因素进行了理论分析，得出用于计算氧化介孔硅有效热导率的计算公式. 采用双槽电化学腐蚀法制备介孔硅，利用微拉曼光谱技术研究了氧化介孔硅热导率随所制备介孔硅孔隙率的变化规律，比较了经不同温度处理的氧化介孔硅的导热性能差异. 孔隙率为60%，73.4%和78.8%的所制备介孔硅经300℃氧化处理后，其热导率值为8.625W/(m·K)，3.846W/(m·K)和1.817W/(m·K)；孔隙率为73.4 关键词： 理论模型 氧化介孔硅 微拉曼光谱 有效热导率

Micro-Raman spectroscopic investigation of the thermal conductivity of oxidized meso-porous silicon

A theoretical model describing the thermal conductivity of oxidized meso-porous silicon (meso-PS) was brought forward, which was based on the effective medium theory for the mechanisms of heat transfer in oxidized meso-PS. The factors affecting effective thermal conductivity (ETC) of oxidized meso-PS were analyzed theoretically, and a calculating formula of TC of oxidized meso-PS was given. Meso-PS samples were prepared by double-tank electrochemical corrosion method. Using Micro-Raman spectroscopic technique, the dependence of TC values of oxidized meso-PS samples on porosities of as-prepared meso-PS was studied and the thermal property of oxidized meso-PS with different oxidized temperatures was compared. TC values yielded by Micro-Raman spectroscopic technique of as-prepared meso-PS with porosities of 60%,73.4% and 78.8% oxidized at 300℃ were 8.625，3.846 and 1.817W/(m·K), respectively, while that of as prepared meso-PS with a porosity of 73.4% oxidized at 450℃ and 600℃ were 2.466 and 2.100 W/(m·K), respectively. And their corresponding theoretical ETC values were 4.549,2.432,1.792,2.105 and 2.096 W/(m·K), respectively. It was shown that the theoretical values were in good agreement with experimental data. Oxidized meso-PS with lower TC and desirable mechanical stability is well suited for thermal insulation material, which is attractive to the application in thermal-effect-micro-systems (TEMS).