Pb- and La-doped (Bi,Pb)2(Ba,La)2Co2Oy ceramics were prepared by solid-state reaction method and the effect of element doping on the thermoelectric characteristics was investigated. Pb and La doping increased the electrical conductivity and transformed the conduction from a metal-like behavior to a semiconducting one. Different from the undoped samples, the values of Seebeck coefficients decreased with the increase of the temperature in the Pb- and La-doped samples. Pb doping in Bi2Ba2Co2Oy system improved the thermoelectric characteristics at high temperature and Pb/La co-doping improved thermoelectric characteristics at low temperature.

Bi2Sr2Co2-xCuxOy (x=0.0, 0.2, 0.4) samples were prepared by solid-state reaction method and the effect of Cu substitution on the high-temperature thermoelectric properties was investigated. The presence of Cu element improved the grain size and the thermoelectric properties increased owing to the simultaneous increase of conductivity and Seebeck coefficients. The optimal thermoelectric performance was obtained in x=0.2 sample and the power factor was two times as large as that in Cu-free sample at 923K.

Co2-xCuxOy (x=0.0, 0.2, 0.4) Samples were prepared by solid-state reaction method and the effect of Cu substitution on the thermoelectric properties was investigated. The presence of Cu element improved the grain size and electrical conductivity, but Seebeck coefficients were reduced by Cu substitution. It was found Cu substitution is an effective way to improve the thermoelectric performance system at high temperature.

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High quality zinc blende ZnSe nanocrystals were successfully synthesized using an environmentally friendierly phosphine-free method. Using pre-synthesized ZnSe nanocrystals as core to dope Cu2+ ions, we obtained ZnSe:Cu/ZnSe and ZnSe:Cu/ZnSe/ZnS core/shell nanocrystals. Absorption spectruscopy, photoluminescence (PL) spectruscopy, X-ray diffraction (XRD), and transmission electron microscopy (TEM) were used to characterize the structures and properties of as-synthesized three kinds of nanocrystals. The results demonstrated that nanocrystals had well dispersion and narrow size-distributions, and the PL emission peak of as-synthesized ZnSe:Cu/ZnSe/ZnS core/shell nanocrystals could be easily tuned from 480 nm to 520 nm by using different sized ZnSe cores.