TY - JOUR
T1 - Exploring resonance levels and nanostructuring in the PbTe-CdTe system and enhancement of the thermoelectric figure of merit
AU - Ahn, Kyunghan
AU - Han, Mi Kyung
AU - He, Jiaqing
AU - Androulakis, John
AU - Ballikaya, Sedat
AU - Uher, Ctirad
AU - Dravid, Vinayak P.
AU - Kanatzidis, Mercouri G.
PY - 2010/4/14
Y1 - 2010/4/14
N2 - We explored the effect of Cd substitution on the thermoelectric properties of PbTe in an effort to test a theoretical hypothesis that Cd atoms on Pb sites of the rock salt lattice can increase the Seebeck coefficient via the formation of a resonance level in the density of states near the Fermi energy. We find that the solubility of Cd is less than previously reported, and CdTe precipitation occurs to create nanostructuring, which strongly suppresses the lattice thermal conductivity. We present detailed characterization including structural and spectroscopic data, transmission electron microscopy, and thermoelectric transport properties of samples of PbTe-x% CdTe-0.055% PbI 2 (x = 1, 3, 5, 7, 10), PbTe-1% CdTe-y% PbI2 (y = 0.03, 0.045, 0.055, 0.08, 0.1, 0.2), PbTe-5% CdTe-y% PbI2 (y = 0.01, 0.03, 0.055, 0.08), and PbTe-1% CdTe-z% Sb (z = 0.3, 0.5, 1, 1.5, 2, 3, 4, 5, 6). All samples follow the Pisarenko relationship, and no enhancement of the Seebeck coefficient was observed that could be attributed to a resonance level or a distortion in the density of states. A maximum ZT of ∼1.2 at ∼720 K was achieved for the PbTe-1% CdTe-0.055% PbI2 sample arising from a high power factor of ∼17 μW/(cm K2) and a very low lattice thermal conductivity of ∼0.5 W/(m K) at ∼720 K.
AB - We explored the effect of Cd substitution on the thermoelectric properties of PbTe in an effort to test a theoretical hypothesis that Cd atoms on Pb sites of the rock salt lattice can increase the Seebeck coefficient via the formation of a resonance level in the density of states near the Fermi energy. We find that the solubility of Cd is less than previously reported, and CdTe precipitation occurs to create nanostructuring, which strongly suppresses the lattice thermal conductivity. We present detailed characterization including structural and spectroscopic data, transmission electron microscopy, and thermoelectric transport properties of samples of PbTe-x% CdTe-0.055% PbI 2 (x = 1, 3, 5, 7, 10), PbTe-1% CdTe-y% PbI2 (y = 0.03, 0.045, 0.055, 0.08, 0.1, 0.2), PbTe-5% CdTe-y% PbI2 (y = 0.01, 0.03, 0.055, 0.08), and PbTe-1% CdTe-z% Sb (z = 0.3, 0.5, 1, 1.5, 2, 3, 4, 5, 6). All samples follow the Pisarenko relationship, and no enhancement of the Seebeck coefficient was observed that could be attributed to a resonance level or a distortion in the density of states. A maximum ZT of ∼1.2 at ∼720 K was achieved for the PbTe-1% CdTe-0.055% PbI2 sample arising from a high power factor of ∼17 μW/(cm K2) and a very low lattice thermal conductivity of ∼0.5 W/(m K) at ∼720 K.
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U2 - 10.1021/ja910762q
DO - 10.1021/ja910762q
M3 - Article
C2 - 20235578
AN - SCOPUS:77950799840
VL - 132
SP - 5227
EP - 5235
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 14
ER -