Numerical analysis of the photoacoustic spectra of silicon samples with differently treated surfaces

This paper presents results of the photoacoustic (PA) spectral studies of a series of silicon samples with differently prepared surfaces. The PA amplitude and phase spectra of the samples indicated existence of the damaged surface layers. In the paper the two layer mathematical model of a sample with a damaged surface layer, that was used for numerical interpretation of the amplitude and phase PA spectra of the investigated samples, is presented and discussed. This model comprises the Urbach edge contribution to the optical absorption coefficient spectrum and it enabled observation of its influence on the PA amplitude spectra of silicon samples.