Thin semiconducting thermoelectric films with narrow energy band gaps are considered to be very promising for future microdevice applications (sensors and generators). The polycrystalline BiSbTe alloys (V–VI semiconductors) are examples. In this report, the detailed temperature dependence of electrical resistivity $\mathrm{[\rho (T)],}$ n- and p-type carrier concentration $\mathrm{[n(T)}$ and $\mathrm{p(T)],}$ and Hall mobility $\mathrm{[\mu (T)]}$ of n-type ${\mathrm{Bi}}_{\mathrm{2}}{\mathrm{Te}}_{\mathrm{3}},$ p-type ${\mathrm{Sb}}_{\mathrm{2}}{\mathrm{Te}}_{\mathrm{3}},$ and p-type $({\mathrm{Bi}}_{\text{1−x}}{\mathrm{Sb}}_x{)}_2{\mathrm{Te}}_{\mathrm{3}}$ $\text{(x=0.73}$ and 0.77) alloy films prepared by metalorganic chemical vapor deposition are presented in the range of 100–500 K. From the room temperature measurement of the Seebeck coefficient (α), the values of α for ${\mathrm{Bi}}_{\mathrm{2}}{\mathrm{Te}}_{\mathrm{3}},$ ${\mathrm{Sb}}_{\mathrm{2}}{\mathrm{Te}}_{\mathrm{3}},$ and $({\mathrm{Bi}}_{\text{1−x}}{\mathrm{Sb}}_x{)}_2{\mathrm{Te}}_{\mathrm{3}}$ with $\text{x=0.73}$ and 0.77 are found to be −220, +110, +240, and +210 μV/K, respectively, which are optimal in these types of film materials. The carrier concentration of these films at 300 K is found to be around ${\text{(10}}^{19}{\text{–10}}^{20}\mathrm{) }{\mathrm{cm}}^{\mathrm{-3}}.$ The $\mathrm{\rho (T)}$ data show an exponential increase with increasing temperature irrespective of the carrier types. For the temperature dependence of the Hall mobility, the lattice contribution is found to be predominant for all the films. Also, we have fabricated a simple micromodule Peltier device (MMP) using the n-type ${\mathrm{Bi}}_{\mathrm{2}}{\mathrm{Te}}_{\mathrm{3}}$ and the p-type $({\mathrm{Bi}}_{\text{1−x}}{\mathrm{Sb}}_x{)}_2{\mathrm{Te}}_{\mathrm{3}}$ $\text{(x=0.77)}$ films where a maximum cooling of 2.6 °C was obtained with a low input current of 2.5 mA.

The results of the studies of structural, electrical, and thermoelectric properties of binary skutterudite ${\mathrm{CoSb}}_3$ thin films are presented. The n-type films were prepared without intentional doping on oxidized Si(100) and ceramic ${\mathrm{Al}}_2{\mathrm{O}}_3$ substrates using magnetron dc sputtering technique. The electron probe microanalysis has shown that the composition of the films is strongly affected by the preparation conditions. The x-ray measurements indicate the films to be amorphous if they are deposited on substrates kept at room temperature. On the basis of the differential thermal and x-ray analyses data, the temperature of the transition from the amorphous to crystalline state was established to be $\text{(153±1)°}\mathrm{C}.$ The films are polycrystalline with a preferential orientation of the growth along the (310) direction of the ${\mathrm{CoSb}}_3$ lattice if grown on substrates kept at 200 °C. The electrical resistivity $\mathrm{\rho (T)}$ and the Seebeck coefficient $\mathrm{S(T)}$ were measured from room temperature up to about 700 K. The value of $\mathrm{\rho (T)}$ decreases with increasing temperature. The maximum absolute value of the Seebeck coefficient is found to be −250 μV/K at around 550 K for both substrates. This is the highest value of the Seebeck coefficient for ${\mathrm{CoSb}}_3$ films deposited by dc magnetron sputtering. The predominant mechanisms of the scattering in ${\mathrm{CoSb}}_3$ are discussed on the basis of the temperature dependence of the Hall mobility. The carrier concentration $\mathrm{n(T)}$ is found to be around ${\text{1.2×10}}^{19}\hspace{0.17em}{\mathrm{cm}}^{\text{−3}}$ at 300 K and is almost constant over the temperature range of (250–400) K. The room temperature measurements of the thermal conductivity carried out by the 3ω method have shown a value of about 3 W/(m K), which is significantly lower than that reported for bulk material.