  We examined the electrical transport properties of densified LaOBiS2-xSex,
which constitutes a new family of thermoelectric materials. The power factor
increased with increasing concentration of Se, i.e., Se substitution led to an
enhanced electrical conductivity, without suppression of the Seebeck
coefficient. Hall measurements indicated that the low electrical resistivity
resulted from increases in the carrier mobility, and the decrease in carrier
concentration led to large absolute values of the Seebeck coefficient of the
system.
