Thermoelectric properties of splat‐cooled amorphous In20Te80, Ga20Te80, and Ge15Te85

摘要

The electrical transport properties of splat‐cooled amorphous semiconductors In20Te80, Ga20Te80, and Ge15Te85 were investigated by measuring the thermoelectric power S and dc resistivity ρ between 140 and 300 °K. For as‐quenched samples, both S and logρ show linear relationships with 1/T, indicating a p‐type intrinsiclike conduction ≳90% due to holes. To account for this intrinsiclike conduction, we propose a high degree of structural integrity in the splat‐cooled amorphous samples, i.e., a structure having the homogeneity of the liquid and consisting of continuous Te chains with In, Ga, and Ge attached to broken bonds. However, annealed samples show extrinsiclike conduction from 0 to -130 °C, and both S and logρ show decrease linearly with respect to the decrease of temperature T. The effect of heat treatment interpreted as a structural disordering, appears due to atomic segregation at local areas.