Photoacoustic CdTe surface characterization

Abstract.

 The correlation between the surface roughness and the surface recombination velocity in CdTe is explored. This is achieved through the use of atomic force microscopic analysis and the investigation of the photoacoustic signal as a function of the modulation frequency in a heat-transmission configuration. It is also shown that in the modulation frequency range where the samples are thermally thick, analyses of the photoacoustic signal amplitude and phase can single-out the different non-radiative recombination heat sources responsible for the signal, even in the case where the regimes are strongly mixed. The procedure employed in this investigation reveals as a very promising method in the field of characterization of surface finishes in semiconductors.