Thermal conductivity measurement of thermoelectric films using transient Photo-Electro-Thermal technique

Accurate and rapid measurement of thermal conductivity of thin films has been a challenge so far in the field of thermoelectric (TE) materials and devices. Herein, we proposed to use a transient photo-electro-thermal (TPET) technique to measure the thermal conductivity of TE thin-films with convenience. Combining theoretical and experimental methods, we found that the TPET technique using laser beam heating can significantly reduce the influence of Peltier effect and thus achieve high test accuracy. The measurement uncertainty of TPET technique for TE films can be depressed below 10%. Furthermore, this method is not only applicable for free-standing thin film, but also for thin film deposited on as-known substrates. Finally, thermal conductivity of several films including p-type Bi0.5Sb1.5Te3, n-type Ag2Se, and n-type Bi2Te3 deposited on PI film at different temperature are accurately measured, which demonstrates the wide applicability of TPET technique on semiconductor films.