Thermophysical analysis of II-VI semiconductors by PPE calorimetry and lock-in thermography

Abstract

An accurate determination of thermophysical properties such as thermal diffusivity, thermal effusivity and thermal conductivity is extremely important for characterization and quality assurance of semiconductors. Thermal diffusivity and effusivity of some binary semiconductors have been investigated. Two experimental techniques were used: a contact technique (PPE calorimetry) and a non contact technique (lock-in thermography). When working with PPE, in the back (BPPE) configuration and in the thermally thick regim of the pyroelectric sensor, we can get the thermal diffusivity of the sample by performing a scanning of the excitation frequency of radiation. Thermal effusivity is obtained in front configuration (sensor directly irradiated and sample in back position) by performing a thickness scan of a coupling fluid. By using the lock-in thermography technique, the thermal diffusivity of the sample is obtained from the phase image. The results obtained by the two techniques are in good agreement. Nevertheless, for the determination of thermal diffusivity, lock-in thermography is preferred.