skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: All-Scale Hierarchically Structured p-Type PbSe Alloys with High Thermoelectric Performance Enabled by Improved Band Degeneracy

Journal Article · · Journal of the American Chemical Society
DOI:https://doi.org/10.1021/jacs.9b00967· OSTI ID:1777264

We show an example of hierarchically designing electronic bands of PbSe toward excellent thermoelectric performance. We find that alloying 15 mol % PbTe into PbSe causes a negligible change in the light and heavy valence band energy offsets (ΔEV) of PbSe around room temperature; however, with rising temperature it makes ΔEV decrease at a significantly higher rate than in PbSe. In other words, the temperature-induced valence band convergence of PbSe is accelerated by alloying with PbTe. On this basis, applying 3 mol % Cd substitution on the Pb sites of PbSe0.85Te0.15 decreases ΔEV and enhances the Seebeck coefficient at all temperatures. Here, excess Cd precipitates out as CdSe1-yTey, whose valence band aligns with that of the p-type Na-doped PbSe0.85Te0.15 matrix. This enables facile charge transport across the matrix/precipitate interfaces and retains the high carrier mobilities. Meanwhile, compared to PbSe the lattice thermal conductivity of PbSe0.85Te0.15 is significantly decreased to its amorphous limit of 0.5 W m-1 K-1. Consequently, a highest peak ZT of 1.7 at 900 K and a record high average ZT of ~1 (400-900 K) for a PbSe-based system are achieved in the composition Pb0.95Na0.02Cd0.03Se0.85Te0.15, which are ~70% and ~50% higher than those of Pb0.98Na0.02Se control sample, respectively.

Research Organization:
Northwestern Univ., Evanston, IL (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES); ONR; Natural Science Foundation of China
Grant/Contract Number:
SC0014520; N00014-18-1-2102; 11804261
OSTI ID:
1777264
Journal Information:
Journal of the American Chemical Society, Vol. 141, Issue 10; ISSN 0002-7863
Publisher:
American Chemical Society (ACS)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 66 works
Citation information provided by
Web of Science

References (34)

Thermopower enhancement in Pb1−xMnxTe alloys and its effect on thermoelectric efficiency journal September 2012
Temperature dependent band gap in PbX (X = S, Se, Te) journal December 2013
Rationally Designing High-Performance Bulk Thermoelectric Materials journal August 2016
Valence Band Modification and High Thermoelectric Performance in SnTe Heavily Alloyed with MnTe journal August 2015
Thermoelectric alloys between PbSe and PbS with effective thermal conductivity reduction and high figure of merit journal January 2014
Weak electron-phonon coupling contributing to high thermoelectric performance in n-type PbSe journal May 2012
Effect of Point Imperfections on Lattice Thermal Conductivity journal November 1960
Origin of the High Performance in GeTe-Based Thermoelectric Materials upon Bi 2 Te 3 Doping journal August 2014
Understanding the role and interplay of heavy-hole and light-hole valence bands in the thermoelectric properties of PbSe journal February 2015
All-scale hierarchical thermoelectrics: MgTe in PbTe facilitates valence band convergence and suppresses bipolar thermal transport for high performance journal January 2013
Tuning bands of PbSe for better thermoelectric efficiency journal January 2014
Extraordinary role of Hg in enhancing the thermoelectric performance of p-type SnTe journal January 2015
Codoping in SnTe: Enhancement of Thermoelectric Performance through Synergy of Resonance Levels and Band Convergence journal April 2015
Cubic AgPbmSbTe2+m: Bulk Thermoelectric Materials with High Figure of Merit journal February 2004
Cooling, Heating, Generating Power, and Recovering Waste Heat with Thermoelectric Systems journal September 2008
Thermal and Optical Energy Gaps in PbTe journal December 1966
High Thermoelectric Performance via Hierarchical Compositionally Alloyed Nanostructures journal May 2013
Strained endotaxial nanostructures with high thermoelectric figure of merit journal January 2011
Synthesis and thermoelectric properties of the PbSe1−xTex alloys journal March 2011
Convergence of electronic bands for high performance bulk thermoelectrics journal May 2011
Size-Dependent Valence and Conduction Band-Edge Energies of Semiconductor Nanocrystals journal June 2011
Enhancement of Thermoelectric Efficiency in PbTe by Distortion of the Electronic Density of States journal July 2008
A low-temperature study of manganese-induced ferromagnetism and valence band convergence in tin telluride journal May 2016
Chemical Insights into PbSe– x %HgSe: High Power Factor and Improved Thermoelectric Performance by Alloying with Discordant Atoms journal November 2018
Lower limit to the thermal conductivity of disordered crystals journal September 1992
High-performance bulk thermoelectrics with all-scale hierarchical architectures journal September 2012
High Thermoelectric Figure of Merit in PbTe Alloys Demonstrated in PbTe-CdTe journal April 2012
Non-equilibrium processing leads to record high thermoelectric figure of merit in PbTe–SrTe journal July 2016
High Thermoelectric Performance of p-Type SnTe via a Synergistic Band Engineering and Nanostructuring Approach journal May 2014
The Criteria for Beneficial Disorder in Thermoelectric Solid Solutions journal October 2012
Structure of the second valence band in PbTe journal July 1977
Nanostructures versus Solid Solutions:  Low Lattice Thermal Conductivity and Enhanced Thermoelectric Figure of Merit in Pb 9.6 Sb 0.2 Te 10 - x Se x Bulk Materials journal November 2006
Model for Lattice Thermal Conductivity at Low Temperatures journal February 1959
Heavily Doped p-Type PbSe with High Thermoelectric Performance: An Alternative for PbTe journal February 2011

Cited By (5)

High Thermoelectric Performance in PbSe–NaSbSe 2 Alloys from Valence Band Convergence and Low Thermal Conductivity journal July 2019
3D extruded composite thermoelectric threads for flexible energy harvesting journal December 2019
Discordant nature of Cd in PbSe: off-centering and core–shell nanoscale CdSe precipitates lead to high thermoelectric performance journal January 2020
Thermoelectric (Bi,Sb) 2 Te 3 –Ge 0.5 Mn 0.5 Te composites with excellent mechanical properties journal January 2019
Realizing high thermoelectric performance in GeTe through decreasing the phase transition temperature via entropy engineering journal January 2019