Photoacoustic investigation of semiconductors: Influence of carrier diffusion and recombination in PbTe and Si

Abstract

The photoacoustic signal of a narrow-gap semiconductor and of Si is investigated as a function of the modulation frequency through the use of a heat-transmission configuration. It is shown that in the thermally thick modulation-frequency range the signal amplitude can single out the different heating sources responsible for the photoacoustic signal. It is also shown that from the signal phase data, as a function of the modulation frequency, we can obtain the values of the surface recombination velocity and the nonradiative band-to-band recombination time.