Enhancement of Thermoelectric Performance of Lead Chalcogenides: PbTe, PbSe and PbS, Due To Temperature Dependent Light and Heavy Hole Valence Band Convergence.

POSTER

Abstract

Among many other interesting properties, Lead Chalcogenides are known for their remarkable thermoelectric performance. We have conducted temperature dependent Angle Resolved Photoemission Spectroscopy (ARPES) study of the electronic structures of Lead Chalcogenides, PbTe, PbSe and PbS. Our observations provide direct evidence for the existence of light-hole upper valence bands and so far undetected heavy-hole lower valence bands in these materials. An unusual temperature dependent relative movement between these bands was detected. This movement leads to a monotonic decrease in the energy separation between their maxima with the increase of temperature. This phenomenon is referred to as band convergence and is believed to be the driving factor behind extraordinary thermoelectric performances of Lead Chalcogenides at elevated temperatures.

Authors

  • Kapila Wijayaratne

    Univ of Virginia

  • S.S. Gupta

    Department of Applied Mathematics & Sciences, Khalifa University, Abu Dhabi 127788, UAE, Physics Department, Kalamazoo College, Kalamazoo, Michigan 49006, USA, National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA, Indian Institute of Technology Ropar, Nangal Road, Rupnagar (Ropar), Punjab 140 001, India, The Institute for Nuclear Research, Moscow, Davidson Coll, Western kentucky University, Bowling Green, KY 42101, Naval Postgraduate School, Austin Peay State University, Univ of Tennessee, Knoxville, University of Nebraska, Rajarata University of Sri Lanka, University of West Georgia, Department of Physics, University of Alabama at Birmingham, Center for High Pressure Science and Technology Advanced Research, Northwestern Univ, Univ of Virginia, Western Kentucky University, Physics Dept. Bowling Green, KY, Department of Physics, The University of Texas-Rio Grande Valley, TX 78539, Western Kentucky University, Bowling Green, KY 42101, Western Kentucky University, School of Electronic and Electrical Engineering, University of Leeds, Leeds LS2 9JT, United Kingdom, Austin Peay State Univ, University of Pardubice, Clemson University, Appalachian State Univ, Department of Physics, University of West Georgia, Department of Geosciences, University of West Georgia, Department of Physics and Astronomy, Georgia State University, Francis Marion University, The Pennsylvania State University, Auburn University, Department of Physics & Astronomy, Louisiana State University, Baton Rouge, Louisiana, Department of Physics, Brigham Young University-Idaho, Rexburg, Idaho, Department of Physics,North Carolina State University, William Mong Institute of Nano Science and Technology, MSTD, Oak Ridge National Laboratory, Department of Physics and Astronomy, Vanderbilt University, Univ of Bristol, University of Alabama in Birmingham, Georgia Institute of Technology, Sandia National Laboratories, University of South Florida

  • S.S. Gupta

    Department of Applied Mathematics & Sciences, Khalifa University, Abu Dhabi 127788, UAE, Physics Department, Kalamazoo College, Kalamazoo, Michigan 49006, USA, National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA, Indian Institute of Technology Ropar, Nangal Road, Rupnagar (Ropar), Punjab 140 001, India, The Institute for Nuclear Research, Moscow, Davidson Coll, Western kentucky University, Bowling Green, KY 42101, Naval Postgraduate School, Austin Peay State University, Univ of Tennessee, Knoxville, University of Nebraska, Rajarata University of Sri Lanka, University of West Georgia, Department of Physics, University of Alabama at Birmingham, Center for High Pressure Science and Technology Advanced Research, Northwestern Univ, Univ of Virginia, Western Kentucky University, Physics Dept. Bowling Green, KY, Department of Physics, The University of Texas-Rio Grande Valley, TX 78539, Western Kentucky University, Bowling Green, KY 42101, Western Kentucky University, School of Electronic and Electrical Engineering, University of Leeds, Leeds LS2 9JT, United Kingdom, Austin Peay State Univ, University of Pardubice, Clemson University, Appalachian State Univ, Department of Physics, University of West Georgia, Department of Geosciences, University of West Georgia, Department of Physics and Astronomy, Georgia State University, Francis Marion University, The Pennsylvania State University, Auburn University, Department of Physics & Astronomy, Louisiana State University, Baton Rouge, Louisiana, Department of Physics, Brigham Young University-Idaho, Rexburg, Idaho, Department of Physics,North Carolina State University, William Mong Institute of Nano Science and Technology, MSTD, Oak Ridge National Laboratory, Department of Physics and Astronomy, Vanderbilt University, Univ of Bristol, University of Alabama in Birmingham, Georgia Institute of Technology, Sandia National Laboratories, University of South Florida

  • U. Chatterjee

    Univ of Virginia