Dynamical study of heat transport properties of porous silicon

Abstract

A new fast technique to determine thermal conductivity of porous silicon is proposed. 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 show the value of 35 W·m–1·K–1. The method can be easily applied for any other porous or otherwise structured low-dimensional media.