Abstract
We present a detailed study of the charge transport, infrared optical reflectivity, and thermal transport properties of n-type PbSe crystals. A strong scattering, mobility-limiting mechanism was revealed to be at play at temperatures above 500 K. The mechanism is indicative of complex electron-phonon interactions that cannot be explained by conventional acoustic phonon scattering alone. We applied the first-order nonparabolicity approximation to extract the density-of-states effective mass as a function of doping both at room temperature and at 700 K. The results are compared to those of a parabolic band model and in light of doping-dependent studies of the infrared optical reflectivity. The thermal conductivity behavior as a function of temperature shows a strong deviation from the expected Debye-Peierls high-temperature behavior (umklapp dominated) indicating an additional heat-carrying channel, which we associate with optical phonon excitations. The correlation of the thermal conductivity observations to the high-temperature carrier mobility behavior is discussed. The thermoelectric figure of merit exhibits a promising value of ∼ 0.8 at 700 K at ∼1.5×1019 cm-3.
| Original language | English |
|---|---|
| Article number | 155207 |
| Journal | Physical Review B - Condensed Matter and Materials Physics |
| Volume | 84 |
| Issue number | 15 |
| DOIs | |
| Publication status | Published - Oct 18 2011 |
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ASJC Scopus subject areas
- Condensed Matter Physics
- Electronic, Optical and Magnetic Materials
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High-temperature charge and thermal transport properties of the n-type thermoelectric material PbSe. / Androulakis, John; Chung, Duck Young; Su, Xianli; Zhang, Li; Uher, Ctirad; Hasapis, Thomas C.; Hatzikraniotis, Euripides; Paraskevopoulos, Konstantinos M.; Kanatzidis, Mercouri G.
In: Physical Review B - Condensed Matter and Materials Physics, Vol. 84, No. 15, 155207, 18.10.2011.Research output: Contribution to journal › Article
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TY - JOUR
T1 - High-temperature charge and thermal transport properties of the n-type thermoelectric material PbSe
AU - Androulakis, John
AU - Chung, Duck Young
AU - Su, Xianli
AU - Zhang, Li
AU - Uher, Ctirad
AU - Hasapis, Thomas C.
AU - Hatzikraniotis, Euripides
AU - Paraskevopoulos, Konstantinos M.
AU - Kanatzidis, Mercouri G
PY - 2011/10/18
Y1 - 2011/10/18
N2 - We present a detailed study of the charge transport, infrared optical reflectivity, and thermal transport properties of n-type PbSe crystals. A strong scattering, mobility-limiting mechanism was revealed to be at play at temperatures above 500 K. The mechanism is indicative of complex electron-phonon interactions that cannot be explained by conventional acoustic phonon scattering alone. We applied the first-order nonparabolicity approximation to extract the density-of-states effective mass as a function of doping both at room temperature and at 700 K. The results are compared to those of a parabolic band model and in light of doping-dependent studies of the infrared optical reflectivity. The thermal conductivity behavior as a function of temperature shows a strong deviation from the expected Debye-Peierls high-temperature behavior (umklapp dominated) indicating an additional heat-carrying channel, which we associate with optical phonon excitations. The correlation of the thermal conductivity observations to the high-temperature carrier mobility behavior is discussed. The thermoelectric figure of merit exhibits a promising value of ∼ 0.8 at 700 K at ∼1.5×1019 cm-3.
AB - We present a detailed study of the charge transport, infrared optical reflectivity, and thermal transport properties of n-type PbSe crystals. A strong scattering, mobility-limiting mechanism was revealed to be at play at temperatures above 500 K. The mechanism is indicative of complex electron-phonon interactions that cannot be explained by conventional acoustic phonon scattering alone. We applied the first-order nonparabolicity approximation to extract the density-of-states effective mass as a function of doping both at room temperature and at 700 K. The results are compared to those of a parabolic band model and in light of doping-dependent studies of the infrared optical reflectivity. The thermal conductivity behavior as a function of temperature shows a strong deviation from the expected Debye-Peierls high-temperature behavior (umklapp dominated) indicating an additional heat-carrying channel, which we associate with optical phonon excitations. The correlation of the thermal conductivity observations to the high-temperature carrier mobility behavior is discussed. The thermoelectric figure of merit exhibits a promising value of ∼ 0.8 at 700 K at ∼1.5×1019 cm-3.
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U2 - 10.1103/PhysRevB.84.155207
DO - 10.1103/PhysRevB.84.155207
M3 - Article
VL - 84
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
SN - 1098-0121
IS - 15
M1 - 155207
ER -