15,050 research outputs found

    Optical properties of cubic and rhombohedral GeTe

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    Calculations of the optical properties of GeTe in the cubic NaCl and rhombohedral ferroelectric structures are reported. The rhombohedral ferroelectric distortion increases the band gap from 0.11 eV to 0.38 eV. Remarkably, substantial changes in optical properties are found even at high energies up to 5 eV. The results are discussed in relation to the bonding of GeTe and to phase change materials based on it

    Thermoelectric properties of β{\beta}-FeSi2_{\text2}

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    We investigate the thermoelectric properties of β{\beta}-FeSi2_{\text2} using first principles electronic structure and Boltzmann transport calculations. We report a high thermopower for both \textit{p}- and \textit{n}-type β{\beta}-FeSi2_{\text2} over a wide range of carrier concentration and in addition find the performance for \textit{n}-type to be higher than for the \textit{p}-type. Our results indicate that, depending upon temperature, a doping level of 3×1020\times10{^{20}} - 2×1021\times10{^{21}} cm3{^{-3}} may optimize the thermoelectric performance

    Prediction of Room Temperature High Thermoelectric Performance in n-type La(Ru,Rh)4Sb12

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    First principles calculations are used to investigate the band structure and the transport related properties of unfilled and filled 4d skutterudite antimonides. The calculations show that, while RhSb3 and p-type La(Rh,Ru)4Sb12 are unfavorable for thermoelectric application, n-type La(Rh,Ru)4Sb12 is very likely a high figure of merit thermoelectric material in the important temperature range 150-300 K.Comment: 3 pages, 3 figures. To appear, Appl. Phys. Let