Thermoelectric properties of p-type SrTiO3/graphene layers nanohybrids

We studied the thermoelectric properties of SrTiO3 and graphene layer(s) (GL) nanohybrids between 10 and 300K as a function of GL loading. Thermopower measurements indicate that the nanohybrids are p-type materials with low S values of about 11-21V/K at room temperature. The p-type behavior of the hybrids has been ascribed to the electron accepting nature of GL that leads to the SrTiO3/GL system hole conducting. The temperature dependence of electrical resistivity shows a degenerate semiconducting behavior as indicated by its weak and negative temperature coefficient of resistivity. The room-temperature resistivity decreases by about three orders of magnitude with GL loading ranging from about 10(2) to 10(-1)cm. These nanohybrids exhibit an amorphous behavior of thermal conductivity with a low temperature plateau and a quasilinear increase at high temperatures. The thermoelectric performance ZT is estimated to be of the order of 10(-5) at room temperature for 10% GL loaded SrTiO3.