synthesis of Thermoelectric materials are capable of converting heat directly into electrical energy. The Seebeck effect, discovered by Thomas Johann Seebeck in 1821 He observed that when two dissimilar materials were joined together and the junctions were held at different temperatures a voltage difference develops which was proportional to the temperature difference. The ratio of the voltage developed to the temperature gradient (ΔV/ΔT) is related to an intrinsic property of the materials, known as the Seebeck coefficient, α. The Seebeck coefficient is very low for metals (only a few µV/K) and much larger for semiconductors (typically a few hundred µV/K). The phenomenon of an electrical current induced by a temperature gradient was termed ‘‘Thermoelectricity”. Physical properties of thermoelectricity have explained for this phenomenon: mobile charge carriers (electrons or holes) at the hot side of the Material have more thermal energy than carriers at the cold side, causing a net diffusion of mobile carriers to the cold side. Since there are more mobile carriers at the cold side than the hot side, the inhomogeneous charge distribution forms an electric field which opposes the diffusion. If the material is in an open circuit, equilibrium will be reached when the rate at which carriers diffuse from the hot side to the cold side is balanced by the rate at which carriers move from the cold side to the hot side, due to the electric field. Thus in equilibrium an electrochemical potential will form in response to a temperature gradient; this electrochemical potential is known as the Seebeck voltage. The amount of voltage generated per unit temperature gradient is called the Seebeck coefficient. If the material is connected to a circuit, the electrochemical potential will drive a current which can be used to perform electrical work.