Low-temperature photoacoustic measurements by a transducer technique

Abstract
A simple technique for photoacoustic spectroscopy at low temperature using a rf-sputtered ZnO film transducer is described. We succeed in obtaining the spectra of InSe at low temperatures. The signals due to the free exciton annihilation and the nonradiative donor to valence band transition are clarified by the present technique. These results establish the usefulness of low-temperature photoacoustic spectroscopy for studying transition processes in semiconductors.