Heavily doped silicon and nickel silicide nanocrystal composite films with enhanced thermoelectric efficiency

In this study, we have developed highly efficient thermoelectric materials based on p-type and n-type composite films of Si nanocrystals and Ni silicide nanocrystals. The heavy doping of the films with boron or phosphorus and thermal annealing of the films caused formation of nanocrystals with high electrical conductivities, low thermal conductivities, and high Seebeck coefficients, consequently leading to the high dimensionless figures of merit (ZT). For the p-type (B-doped) and n-type (p-doped) films, ZT is 0.13 and 0.06, respectively, which were much higher than that of bulk Si (<0.01) at RT and nanostructured bulk Si.