Abstract
We investigated the effects of nano-structure (pore size and depth) on the thermoelectric properties of porous p-Bi_<0.4>Te_3Sb_<1.6> and n-Bi_<2.0>Te_<2.7>Se_<0.3> thin films.The cross-plane thermal conductivity of the porous p-Bi_<0.4>Te_3Sb_<1.6> and n-Bi_<2.0>Te_<2.7>Se_<0.3> thin films is 0.26 and 0.22 W m^<-1> K^<-1>, respectively. The value was significantly reduced from that of standard p- and n-type flush evaporated bismuth telluride films. The figure of merit (ZT) of the porous p-Bi_<0.4>Te_3Sb_<1.6> and n-Bi_<2.0>Te_<2.7>Se_<0.3> thin films is estimated to be ZT = 1.30, 1.47, respectively. We evaluated the thermoelectric power generation of porous and flat p-Bi_<0.4>Te_3Sb_<1.6> single cell. The output power is improved 25 % by nano porous structure.
