Dynamical study of thermal conductivity of nanostructured layers by use of the photoinduced transient thermoelectric effect

Abstract

We propose a new fast technique to determine thermal conductivity of a nanostructured material and demonstrate it for porous silicon. Transient thermoelectric voltage is measured after a pulsed laser irradiation, and analysis of the voltage decay time constant and porosity of the structure gives the value of the thermal conductivity. For n-type Si of 70% porosity we obtain the value of 35 W m-1 K-1 what is in good agreement with the results of other investigations. The method can be easily applied for any other porous or otherwise structured low-dimensional materials.