J. Phys. IV France 125 (2005) 169-171
Determination of thermal and optical parameters of the semiconductor CdTe by photopyroelectric spectroscopyJ.E. de Albuquerque, P.M.S. de Oliveira and S.O. Ferreira
Departamento de Física, Universidade Federal de Vicosa, 36571-000 Vicosa/MG, Brazil
In this study, photopyroelectric spectroscopy was used to obtain thermal and optical properties of CdTe in the nm wavelength range, where is the wavelength. The normalized photopyroelectric intensity signal and its phase were independently measured, as well as the intensity Vn(f) and the phase Fn(f) (f being the chopping frequency) for a given of the saturation part of the PPES spectrum. Equations of both the intensity and the phase of the PPES signal, taking into account the thermal and the optical characteristics of the pyroelectric (PVDF) detector, were used to fit the experimental results. From the fitting in the graph Fn(f) versus f1/2, we obtained, with great accuracy, the value of thermal diffusivity coefficient . From the fitting in the graph Vn(f) versus f, we obtained the thermal conductivity k. The specific heat c of the sample is then directly derived from the relation , where is the mass density, valid for a stationary state. From the fittings in the graphs versus and versus , we obtained the optical absorption coefficient and the optical gap of the CdTe.
© EDP Sciences 2005