Enhancement of thermoelectric properties in nanocrystalline M–Si thin film composites (M=Cr, Mn)

Abstract: We study thermoelectric properties, crystallization kinetics and stability of amorphous and nanocrystalline state in Cr–Si and Mn–Si composite films. The as-deposited amorphous films are transformed by annealing with in situ thermopower and electrical resistivity measurements into nanocrystalline state with continuous monitoring their state. Depending on the initial film composition, the films are transformed during the annealing into single phase or multi-phase nanocrystalline composites. A clear correlation between structural state and thermoelectric properties of the composites is found. Particularly, the thermoelectric power factor of nanocrystalline films is enhanced in comparison to the power factor of polycrystalline films, obtained by high-temperature re-crystallization of the nanocrystalline films, due to strong energy dependent charge carrier scattering. [Copyright &y& Elsevier]