Indium tin oxide (ITO) films deposited on single‐crystal Si wafers by the electron‐beam‐(EB) evaporation method have been investigated by x‐ray photoelectron spectroscopy (XPS) together with work‐function and resistivity measurements. The XPS studies suggest that all the ITO films consist of crystalline and amorphous phases. The amount of the crystalline phase with respect to the amorphous phase for the ITO films, deposited with the incident angle of the ITO vapor to the Si substrate θ_i at 0°, is smaller than that for the ITO films deposited at θ_i=45°. The amount of the crystalline phase hardly depends on the conditions of postdeposition heat treatments, while that of the amorphous phase increases by raising the temperature of the heat treatments. Metal indium present in the films deposited at θ_i=0° is transformed into amorphous indium oxide by heating at 450 °C in air. Metal tin is also present near the ITO/Si interface for the ITO films deposited at θ_i=0°. The work function of the ITO films deposited at θ_i=0° is lower by 0.8 eV in maximum than that for the films deposited at θ_i=45°. It is concluded that the work function of the ITO films increases not only with a decrease in the amount of metal indium and metal tin in the films but also with an increase in the amount of the crystalline ITO phase with respect to that of the amorphous phase.

The thermoelectric properties of poly(3,4-ethylenedioxythiophene) (PEDOT)-based materials have attracted attention recently because of their remarkable electrical conductivity, power factor, and figure of merit. In this review, we summarize recent efforts toward improving the thermoelectric properties of PEDOT-based materials. We also discuss thermoelectric measurement techniques and several unsolved problems with the PEDOT system such as the effect of water absorption from the air and the anisotropic thermoelectric properties. In the last part, we describe our work on improving the power output of thermoelectric modules by using PEDOT, and we outline the potential applications of polymer thermoelectric generators.