To elucidate low-dimensional effects on thermoelectric materials, bismuth telluride film and nanowires array were fabricated by potentiostatically electrodeposition. Both materials are slightly Te-rich, n-type Bi2Te3, exhibiting preferred orientation in rhombohedral strcture. For both the Seebeck coefficient S ≈ −70 μV/K at 300 K decreases linearly with decreasing temperature, showing a diffusive nature of current flow. The temperature dependence of resistivity (=1/σ) of nanowires obtained from the data of a nanowires array and a single-nanowire reveals a better electric conductivity than that of the bulk. By coupling temperature-dependent thermal diffusivity and heat capacity data with a modified effective medium theory, a thermal conductivity κ of 0.75 W/(m K) was obtained at 300 K. The ZT was calculated to be 0.45 at 300 K and 0.9 at 350 K for Bi2Te3 nanowires.

The strategy for shape control of alloy FePt nanocrystal was studied systematically. By the careful adjustments of reaction parameters in a solution reaction, surfactant-facet bindings on the growth seed were controlled delicately. FePt octapod, cuboctahedron, truncated cube, and nanocube were successfully prepared from cuboctahedral seed and examined by high-resolution transmission electron microscopy. The formations of FePt nanostructures were mainly attributed to the differences in the growth rate between the {111} and {100} planes of cuboctahedral seeds. The magnetic measurements showed that the order of volume, V (nanocube) >V (octapod) >V (cuboctahedron) obviously reflected the order of saturated magnetization (M s ), M s (nanocube) >M s (octapod) >M s (cuboctahedron) . Furthermore, the measurements of octapod exhibited the highest coercivity and blocking temperature because of its higher surface to volume ratio and more structural facets.

The packing structures and packing effects on excitation energies of thiophene, terthiophene, sexithiophene, and duodecithiophene are studied by employing the molecular dynamic (MD) simulations and the TDDFT/ 6-311++G** calculations. It has been demonstrated by MD simulations that (1) when going from short to long chain systems, the packing structure prefers to be in the π-stacked form and (2) the effective conjugation lengths, ECLs, of terthiophene, sexithiophene, and duodecithiophene chains are 2, 3, and 4, respectively. Accordingly, the comprehensive effects of the interchain distance, R, and ECL on excitation energy can be estimated by a simple formula. The calculated excitation energies of the packing oligothiophenes are in agreement with the experimental data with the average deviation of 0.12 eV.