TY - CPAPER
KW - Heat transfer
KW - Thin films
KW - Pulsed laser deposition
KW - Thermal conductivity
KW - Lanthanum
KW - Strontium titanates
KW - Lanthanum alloys
KW - Oxygen vacancies
KW - Transport measurements
KW - SrTiO
KW - Conduction band edge
KW - Double doping
KW - Impurity bands
KW - Mass defect
KW - Optical spectroscopic
KW - Oxygen deficient
KW - Theoretical prediction
KW - Thermoelectric material
KW - Thermoelectric performance
KW - Thermoelectric power factors
KW - Thermoelectric power
KW - Thermoelectricity
AU - J Ravichandran
AU - W Siemons
AU - J Kardel
AU - H Heijmerikx
AU - A Chari
AU - D Oh
AU - D Cahill
AU - Ramamoorthy Ramesh
AU - A Majumdar
AB - Lanthanum (La) doped Strontium Titanate (SrTiO3) is amongst the most promising n-type thermoelectric materials for power generation. We report a double doping method for thin films of SrTiO3 (STO), grown by Pulsed Laser Deposition (PLD), where doping of STO in the Sr-site by Lanthanum is accompanied by doping with oxygen vacancies. In the past theoretical predictions have shown that introducing oxygen vacancies in STO produces a high-effective mass defect band just below the conduction band edge, explaining the high seebeck coefficient observed in oxygen deficient STO. Based on careful transport measurements, we show that it is possible to obtain enhanced thermoelectric power factor by double doping, using La and oxygen vacancies in these thin films. With the aid of optical spectroscopic measurements, we establish the presence of the impurity band created by the vacancies and validate their role in the enhanced thermoelectric performance with structural and transport measurements. The presence of oxygen vacancies also serves to decrease the thermal conductivity due to effective phonon scattering. © 2010 by ASME.
BT - 2010 14th International Heat Transfer Conference, IHTC 14
DO - 10.1115/IHTC14-22352
LA - eng
N1 - cited By 0
N2 - Lanthanum (La) doped Strontium Titanate (SrTiO3) is amongst the most promising n-type thermoelectric materials for power generation. We report a double doping method for thin films of SrTiO3 (STO), grown by Pulsed Laser Deposition (PLD), where doping of STO in the Sr-site by Lanthanum is accompanied by doping with oxygen vacancies. In the past theoretical predictions have shown that introducing oxygen vacancies in STO produces a high-effective mass defect band just below the conduction band edge, explaining the high seebeck coefficient observed in oxygen deficient STO. Based on careful transport measurements, we show that it is possible to obtain enhanced thermoelectric power factor by double doping, using La and oxygen vacancies in these thin films. With the aid of optical spectroscopic measurements, we establish the presence of the impurity band created by the vacancies and validate their role in the enhanced thermoelectric performance with structural and transport measurements. The presence of oxygen vacancies also serves to decrease the thermal conductivity due to effective phonon scattering. © 2010 by ASME.
PY - 2010
SN - 9780791849392
SP - 839
EP - 843
T2 - 2010 14th International Heat Transfer Conference, IHTC 14
T3 - 2010 14th International Heat Transfer Conference, IHTC 14
TI - Thermoelectricity of double doped strontium titanate
VL - 4
ER -