Investigation on native defects of α-MgAgSb and its effects on thermoelectric properties using first principles calculations

다국어 초록 (Multilingual Abstract)

a-MgAgSb is a promising thermoelectric materials having good performance at medium temperature. Native defects in a-MgAgSb are frequently reported experimentally and are tightly involved in the thermoelectric properties of a-MgAgSb. In this paper, all possible native defects in a-MgAgSb are calculated as well as detailed results are given and discussed. The concentrations of several dominant native defects, for example, VAg and AgSb, could reach up to 104 cm3 at 540 K. Furthermore, the electronic structure and transport properties of a-MgAgSb with dominant native defects are investigated. Results show that the introduction of AgMg and VAg contributes to a much lower inertial mass and slight decrease in Seebeck coefficient. The lattice thermal conductivity is greatly reduced with the introduction of native defects. For a-MgAgSb with VAg, the peak ZT could reach up to 1.84 at 420 K. Our calculation demonstrates that defect engineering is an effective strategy to enhance thermoelectric performance of the materials.

참고문헌 (Reference)

1 P. Blaha, "WIEN2K, an Augmented Plane Waveþ Local Orbitals Program for Calculating Crystal Properties" Technical Universitat Wien 2001

2 R. Siegel, "Vacancy concentrations in metals" 69 : 117-146, 1978

3 Z. Liu, "Understanding and manipulating the intrinsic point defect in a-MgAgSb for higher thermoelectric performance" 4 (4): 16834-16840, 2016

4 L. -D. Zhao, "Ultralow thermal conductivity and high thermoelectric figure of merit in SnSe crystals" 508 (508): 373-377, 2014

5 A.H. Reshak, "Thermoelectric properties for AA- and AB-stacking of a carbon nitride polymorph (C3N4)" 4 (4): 63137-63142, 2014

6 C. Wagner, "Theory of arranged mixed phases" 11 : 163-210, 1930

7 A. Reshak, "Spin-polarized second harmonic generation from the antiferromagnetic CaCoSO single crystal" 7 :

8 H. J. Monkhorst, "Special points for Brillouin-zone integrations" 13 (13): 5188-, 1976

9 G. Nolas, "Skutterudites: a phonon-glass-electron crystal approach to advanced thermoelectric energy conversion applications" 29 (29): 89-116, 1999

10 C. Jiang, "Site preference of early transition metal elements in C15NbCr2" 55 (55): 1599-1605, 2007

11 X. Tang, "Preparation and thermoelectric transport properties of high-performance p-type Bi2 Te3 with layered nanostructure" 90 (90): 12102-12102, 2007

12 G. Davydyuk, "Photoelectrical properties and the electronic structure of Tl1-x In1-x SnxSe2(x= 0, 0.1, 0.2, 0.25) single crystalline alloys" 15 (15): 6965-6972, 2013

13 X. -K. Chen, "Phonon wave interference in graphene and boron nitride superlattice" 109 (109): 023101-, 2016

14 Y. Pei, "Low effective mass leading to high thermoelectric performance" 5 (5): 7963-7969, 2012

15 Z. Liu, "Lithium doping to enhance thermoelectric performance of MgAgSb with weak electronephonon coupling"

16 A. Reshak, "Linear, non-linear optical susceptibilities and the hyperpolarizability of the mixed crystals Ag0.5Pb1.75Ge(S1-x Sex)4: experiment and theory" 15 (15): 18979-18986, 2013

17 J. -F. Li, "High-performance nanostructured thermoelectric materials" 2 (2): 152-158, 2010

18 H. Zhao, "High thermoelectric performance of MgAgSb-based materials" 7 : 97-103, 2014

19 C. G. Van de Walle, "First-principles calculations for defects and impurities: applications to III-nitrides" 95 (95): 3851-3879, 2004

20 Z. -X. Xie, "Enhancement of thermoelectric properties in graphene nanoribbons modulated with stub structures" 100 (100): 073105-, 2012

21 W. -X. Zhou, "Enhancement of thermoelectric performance by reducing phonon thermal conductance in multiple core-shell nanowires" 4 : 7150-, 2014

22 T. Markussen, "Electron and phonon transport in silicon nanowires: atomistic approach to thermoelectric properties" 79 (79): 035415-, 2009

23 G. Kresse, "Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set" 6 (6): 15-50, 1996

24 Z. Liu, "Effects of antimony content in MgAg0.97 Sbx on output power and energy conversion efficiency" 102 : 17-23, 2016

25 J. Callaway, "Effect of point imperfections on lattice thermal conductivity" 120 (120): 1149-, 1960

26 C. Wan, "Effect of point defects on the thermal transport properties of (LaxGd1-x)2Zr2O7: experiment and theoretical model" 74 (74): 144109-, 2006

27 A. H. Reshak, "Dispersion of linear and nonlinear optical susceptibilities and the hyperpolarizability of 3-methyl-4-phenyl-5-(2-pyridyl)-1, 2, 4-triazole" 13 (13): 2945-2952, 2011

28 J. Bardeen, "Deformation potentials and mobilities in non-polar crystals" 80 (80): 72-, 1950

29 P. A. Korzhavyi, "Constitutional and thermal point defects in B2NiAl" 61 (61): 6003-, 2000

30 G. J. Snyder, "Complex thermoelectric materials" 7 (7): 105-114, 2008

31 D. Li, "Atomic disorders induced by silver and magnesium ion migrations favor high thermoelectric performance in a-MgAgSb-based materials" 25 (25): 6478-6488, 2015

32 F. Tran, "Accurate band gaps of semiconductors and insulators with a semilocal exchange-correlation potential" 102 (102): 226401-, 2009

33 M. J. Kirkham, "Abinitio determination of crystal structures of the thermoelectric material MgAgSb" 85 (85): 144120-, 2012

34 A. Reshak, "Ab initio study of TaON, an active photocatalyst under visible light irradiation" 16 (16): 10558-10565, 2014

35 J. -W. Jiang, "A nonequilibrium Green's function study of thermoelectric properties in single-walled carbon nanotubes" 109 (109): 014326-, 2011

36 G. K. Madsen, "A code for calculating band-structure dependent quantities" 175 (175): 67-71, 2006