nonstoichiometry in the films for enhancing p-type conductivity.Details of the deposition conditions were reported elsewhere [22].
The films were characterized by X-ray diffraction (XRD,by CuKa line) to identify the proper phase of the film.Thermoelectric characteristics were measured by copper–constantan thermocouple. Electrical characteristics were measured by standard four-probe method. All contacts were made by silver paste, which showed ohmic characteristics over a wide range of voltages. Thicknesses of the films were estimated from cross-sectional scanning electron microscopy(SEM, JEOL-5200). Compositional analyses of the films were done by energy dispersive X-ray (EDX, Leica S-440, Oxford ISIS) which could detect elements from Boron
(5) to Uranium (92).