PHOTOACOUSTIC SPECTROSCOPY (PAS) OF SEMICONDUCTOR MATERIALS USING TRANSPARENT TRANSDUCER

This is a review of Photoacoustic (PAS) measurement using transparent transducer of semiconductor materials. This technique is very sensitive to detect a PA signal because the light is illuminated to the sample surface through a transparent piezoelectric transducer (LiNbO3) and the PA signal is detected directly from the transducer. In this review the generation mechanisms of PA amplitude and phase signals for layered semiconductor materials (GaInP/GaAs) are experimentally clarified. Then, a theoretical analysis of generation mechanism of PA signal is presented and the validity of the theory is clarified by the experimental results. Finally, the thermal conductivity of InP is estimated by using both the theory and the experiment.