Piezoelectric photoacoustic spectroscopy of surface states of Zn0.81Be0.04Mg0.15Se mixed crystals

This paper presents basics of the space selective piezoelectric photothermal spectroscopy method. This method is illustrated with the experimental piezoelectric amplitude and phase spectra of ZnBeMgSe(4%Be, and 15%Mg) samples and with the corresponding optical transmission spectra. The fitting of theoretical curves computed in the piezoelectric space sensitive spectroscopy method to experimental data indicated the presence of surface states located on both surfaces of the sample. From the fitting procedure the optical absorption coefficient spectra connected with the surface absorption on both sides of the sample were determined.