Investigation on the influence of thickness and temperature on the Seebeck coefficient of silver telluride thin films

The thermal emf of the annealed silver telluride thin films of thickness between 41 and 102 nm, has been measured in the temperature range between 300 and 430 K at a pressure of about 10(-2) mbar by the integral method. The films were annealed at 430 K at a pressure of about 10-2 mbar for an hour. The temperature dependence of the Seebeck coefficient of the orthorhombic and the cubic phases of silver telluride thin films is determined by analyzing our thermal emf data using Taut splines. It is found that the Seebeck coefficient in both the phases is negative and weakly temperature dependent. The structural phase transition with a hysteresis in silver telluride thin films is influenced by the thickness of the films. The thickness dependence of the Seebeck coefficient of the silver telluride films was analyzed on the basis of the 'effective mean free path model'. Our studies reveal that electrons are the majority carriers in silver telluride, and the lattice scattering dominates over the impurity ion scattering. (C) 2002 Elsevier Science Ltd. All rights reserved.