Characterization of semiconductors using photoacoustics

Since the early seventies, photoacoustic has been emerged as a well suited technique for the measurement of optical and transport properties of semiconductors, showing in many cases considerable advantages respecting other characterization methods. As these materials are often grown in the form of thin films on different kind of substrates, in this chapter we shall describe some of the theoretical models devised in the last years to the measurement of their electronic transport properties. We will also show how photoacoustic spectroscopy allows the measurement of the wavelength dependence of the optical absorption coefficient of very opaque semiconductor thin layers