Thermoelectric and Magnetothermoelectric Properties of In-doped Nano-ZnO Thin Films Prepared by RF Magnetron Sputtering

Nano In-doped ZnO (IZO) films were deposited on glass substrates by RF magnetron sputtering from a powder target (2at% In) at different substrate temperatures. The thermoelectric and magnetothermoelectric properties of the IZO films were investigated. It shows that the prepared IZO films are c-axis oriented, the grain size is about 22-29 nm, and both the thermoeletromotive force (thermo-emf) and the magneto thermo-emf change linearly with temperature difference, implying that a striking thermoelectric (Seebeck) effect and magnetothermoelectric effect can be apparently observed in IZO films. The thermo-emf is negative, the Seebeck coefficient is about -57, -32, -40 and -66 mu V/K for samples deposited at the substrate temperature of room temperature, 100, 200, 300A degrees C, respectively. The power factor is (3.11-5.89)x10(-5) W/K-2 m for our thin films. The absolute value of the magnetothermo-emf is smaller than the thermo-emf without a magnetic field, showing that the magnetic field has a negative effect on the Seebeck coefficient, which can be explained by the magnetoresistive effect substantially.