Effect of anion and cation substitution in tungsten disulfide and tungsten diselenide on conductivity and thermoelectric power

The temperature dependences of the conductivity and thermoelectric power for a series of samples W1–x Nb x S2, W1–x Nb x Se2, WS2–y Se y , W1–x Nb x S2–y Se y are studied at low temperatures. It is found that the cation substitution of W atoms with Nb leads to an increase in the conductivity and a decrease in the thermoelectric power. The anion substitution of S with Se atoms results in a simultaneous increase in the conductivity and thermoelectric power. The highest power factor among the samples studied is inherent to W0.8Nb0.2Se2.