[PPT] - New approaches to thermoelectric materials materials A.P. Gonalves PowerPoint Presentation

SLIDE 1

New approaches to thermoelectric materials materials

A.P. Gonçalves ç

Dep. Química, Instituto Tecnológico e Nuclear/CFMC-UL,

P-2686-953 Sacavém, Portugal , g

SLIDE 2

Outline Outline

Introduction New Systems C d i l Conducting glasses Bi doped Te Films p Conclusions

SLIDE 3

ZT = S2Tσ/K

(adimensional, depends only on the material)

S = Seebeck coefficient , σ= electrical conductivity, K = thermal conductivity

Efficiency or Coefficient of Performance maximization ZT

ptimization

Performance maximization

ptimization

M i i ti f S2 ( f t )

Maximization of S2 σ (power factor) Minimization of K

SLIDE 4

Maximization of S2 σ Maximization of S σ

σ S S

2

σ σ S

Metals Insulators Semiconductors 10 14 10 16 10 18 10 20 10 22

Carrier content concentration Carrier content concentration

SLIDE 5

Mi i i ti f K Minimization of K

K = Kelect + Klat

Wiedemann-Franz law

Kelect = LTσ Decrease of K Decrease of Klat

SLIDE 6

Phonon-glass/electron-crystal (PGEC) materials

h ff h Materials

G. Slack, in CRC Handbook of Thermoelectrics, 1995

Approach Effects on phonons (examples) Heavy atoms weakly Phonon-scattering centers Skutterudites bounded to the structures Phonon scattering centers Clathrates Complex structures Increase the optical phonon modes Clathrates Yb MnSb Yb14MnSb11 Inclusions impurities Increase diffusion Composites Inclusions, impurities (affects more phonons than carriers) Composites Increase mass fluctuations Half-Heusler Solid solutions Increase mass fluctuations (higher phonon scattering) Half Heusler systems G i b d i R d th h f th Low dimensional Grain boundaries Reduce the phonons mean free path systems

SLIDE 7

Matériaux thermoélectriques de type n 1.6

Ti0.5(Zr0.5Hf0.5)0.5NiSn0.998Sb0.002 In0.2Ce0.2Co4Sb12

Matériaux thermoélectriques de type n

Type p thermoelectric materials

1.2 1.4

In0.2Co4Sb12 Ba8Ga16Ge30 Ba0.3Co3.95Ni0.05Sb12 LaTe1.45 Bi2-xSbxTe3

0.8 1.0

Si0.80Ge0.20 Pb1-xSnxTe1-ySey C

S

b

3 2-x x 3

ZT 0 4 0.6 0.8

(Zn0.98Al0.02)O - UFP Bi2(Sb,Te)3

Z 0.2 0.4

SrPbO3

β-FeSi2

200 400 600 800 1000 1200 1400 0.0 Température (K) Température (K)

SLIDE 8

Approach Effects on phonons Materials (examples) Heavy atoms weakly Skutterudites Approach Effects on phonons Materials (examples) Heavy atoms weakly Skutterudites Heavy atoms weakly bounded to the structures Phonon-scattering centers Skutterudites Clathrates Clathrates Heavy atoms weakly bounded to the structures Phonon-scattering centers Skutterudites Clathrates Clathrates

Gl

Complex structures Increase the optical phonon modes Clathrates Yb14MnSb11 d ff Complex structures Increase the optical phonon modes Clathrates Yb14MnSb11 d ff

Glasses

Inclusions, impurities Increase diffusion (affects more phonons than carriers) Composites Inclusions, impurities Increase diffusion (affects more phonons than carriers) Composites Solid solutions Increase mass fluctuations (higher phonon-scattering) Half-Heusler systems Solid solutions Increase mass fluctuations (higher phonon-scattering) Half-Heusler systems Grain boundaries Reduce the phonons mean free path Low dimensional systems Grain boundaries Reduce the phonons mean free path Low dimensional systems

SLIDE 9

Conducting Glasses Conducting Glasses

Minimization of K Low Klat

Maximization of S2 σ

SLIDE 10

Metallic Glasses Metallic Glasses

Author(s): LINKESOVA, V; VESELSKY, J Title: TEMPERATURE-DEPENDENCE OF THE SEEBECK COEFFICIENT AND OF METALLIC- GLASS ELECTRIC-RESISTANCE Source: ACTA PHYSICA SLOVACA, 35 (1): 40-46 1985 Author(s): BHATNAGAR, AK; PRASAD, BB; RATHNAM, NRM Title: MAGNETIC ELECTRICAL AND THERMOELECTRIC STUDIES ON METALLIC GLASS

4 T 1000 K

Title: MAGNETIC, ELECTRICAL AND THERMOELECTRIC STUDIES ON METALLIC-GLASS FE39NI39MO4SI6B12 Source: JOURNAL OF NON-CRYSTALLINE SOLIDS, 61-2 (JAN): 1201-1206 1984 Author(s): PEKALA, K; PEKALA, M; TRYKOZKO, R

4 < T < 1000 K

Title: MAGNETIC THERMOELECTRIC-POWER OF FE20NI60B10SI10 METALLIC-GLASS Source: SOLID STATE COMMUNICATIONS, 46 (5): 413-415 1983 Author(s): CARINI, JP; BASAK, S; NAGEL, SR; GIESSEN, BC; TSAI, CL

0 < ⏐S⏐ < 5 µV/K

Title: THE THERMOELECTRIC-POWER OF THE METALLIC-GLASS CA0.8AL0.2 Source: PHYSICS LETTERS A, 81 (9): 525-526 1981 Author(s): TEOH, N; TEOH, W; ARAJS, S; MOYER, CA Title: ABSOLUTE THERMOELECTRIC POWER OF AMORPHOUS METALLIC GLASS FE80B20 Title: ABSOLUTE THERMOELECTRIC-POWER OF AMORPHOUS METALLIC GLASS FE80B20 BETWEEN 300-K AND 1000-K Source: PHYSICAL REVIEW B, 18 (6): 2666-2667 1978 Author(s): NAGEL, SR Title: THERMOELECTRIC-POWER AND RESISTIVITY IN A METALLIC GLASS Source: PHYSICAL REVIEW LETTERS, 41 (14): 990-993 1978

SLIDE 11

Nb Ni Sn Nb32Ni60Sn8

S l t li Splat cooling

SLIDE 12

400

Nb32Ni60Sn8

300

(a.u.)

200

Intensity

100 10 20 30 40 50 60

2θ (º)

S(300 K) = 1 1 µV/K S(300 K) = 1.1 µV/K

SLIDE 13

Semiconducting Glasses Semiconducting Glasses

SLIDE 14

Ge20Te80 - known glass Ge20Te80 known glass semiconductor; Quenching in ice water; Q g Tg = 428 K, Tc = 493.5 K [1];

g

,

c

S(300 K) = 960 µV/K S(300 K) = 960 µV/K, ρ(300 K) = 2.77x108 µΩ µΩm[2].

[1] M Abu El Oyoun J Phys D: Appl Phys 33 (2000) 2211 2217 [1] M Abu El-Oyoun, J. Phys. D: Appl. Phys. 33 (2000) 2211–2217. [2] G. Perthasarathy, A.K. Bandyopadhyay, S. Asokan, E.S.R. Gopal, Solid State Commun. 51 (1984) 195-197.

SLIDE 15

Ge20-xTe80-yMx+y ρ decrease? M = Ag, Cu [1,2] CuxGeyTez general compositions; C T T (T G ) Cu25T5Te70 (T = Si, Ga)

[1] A. Ferhat, R. Ollitrault-Fichet, V. Mastelaro, S. Bénazeth, J. Rivet, J. de Physique IV, 2 (1992) C2-201-C2-206. y q ( ) [2] K. Ramesh, S. Asokan, K.S. Sangunni, E.S.R. Gopal, J. Phys.:

Condens. Matter 8 (1996) 2755-2762.

SLIDE 16

SLIDE 17

Preparation by melt-spinning;

SLIDE 18

SLIDE 19

1500

Cu Ge Te

1500

Cu30Te70 Cu Ge Te

1500

Cu15Ge10Te75 Cu7 5Ge15Te77 5

u.)

1500

Cu15Ge10Te75 Cu7 5Ge15Te77 5

u.)

1000

7.5 15 77.5

Ge20Te80

ty (a.u

1000

7.5 15 77.5

Ge20Te80

ty (a.u

500

ntensi

500

ntensi I

20 30 40 50 60

2 θ (º)

20 30 40 50 60

2 θ (º) 2 θ ( ) 2 θ ( )

SLIDE 20

SLIDE 21

DTA

Cu Ge Te

Tc

0.5

Cu20Ge5Te75 u.)

Tc

2

u.) ux (a.u

4

Cu20Ge5Te75 ux (a.u

1.0

Heat Fl

Tg

6

Heat Fl H

8

H

50 100 150 200 250

Temperature (ºC)

320 330 340 350 360

Temperature (ºC)

SLIDE 22

10

9

10

Cu15Ge7,5Te77,5 Cu20Ge5Te75

10

7

10

8

)

Cu22,5Ge2,5Te75 Cu25Ga5Te70

10

6

10

ρ (µΩ µΩ m)

Cu Ge Te Cu25Si5Te70

10

4

10

5

ρ

Cu27.5Ge2.5Te70

4 6 8 10 12 14 10

3

1000/T (K

1)

SLIDE 23

1000

µV/K)

Cu15Ge7.5Te77.5

500

Cu27.5Ge2.5Te70

power (µ

Cu22.5Ge2.5Te75 Cu20Ge5Te75

Thermop

Cu25Ga5Te70 Cu25Si5Te70

100 200 300

T

100 200 300

T(K)

SLIDE 24

10

8

10

7

)

10

6

(µΩm)

10

5

ρ300 K (

10

4

ρ

70 72 74 76 78 80 10

3

T % Te %

SLIDE 25

10

8

10

7

)

10

6

(µΩm)

10

5

ρ300 K (

10

4

ρ

2 4 6 8 10 12 14 16 18 20 22 10

3

Ge % Ge %

SLIDE 26

10

8

10

7

)

10

6

(µΩm)

10

5

ρ300 K (

10

4

ρ

5 10 15 20 25 30 10

3

Cu %

SLIDE 27

1000 800 600

V/K)

400

S (µV

200 70 72 74 76 78 80

Te %

SLIDE 28

1000 800 600

V/K)

400

S (µV

200 2 4 6 8 10 12 14 16 18 20 22

Ge %

SLIDE 29

1000 800 600

V/K)

400

S (µV

200 5 10 15 20 25 30

Cu %

SLIDE 30

60

K

2m)

40

(µW/K

20

S

2/ρ (

70 72 74 76 78 80

Te %

SLIDE 31

60

) W/K

2m)

40

ρ (µW

20

S

2/ρ

2 4 6 8 10 12 14 16 18 20 22

Ge %

SLIDE 32

60

m)

40

W/K

2m

20

2/ρ (µW

S

2

5 10 15 20 25 30

Cu %

SLIDE 33

Glass ρ300K E (Hi h T) S300K S2/ρ Glass Composition ρ300K (µΩm) Ea(High T) (meV) S300K (µV/K) S /ρ (µWK-2m-1) Cu25Ge5Te70 1000

150

22.5 Cu25Ga5Te70 2540 134 344 47 Cu25Si5Te70 5150 125 357 25

SLIDE 34

Conducting Glasses - Conclusions

Cl s t cr st lliz ti n;

Close to crystallization;
Semiconductor and semimetal behavior;
High Seebeck values;
Moderately high resistivities;
Low gap;
Cu increases → Power factor increases;

Cu increases → Power factor increases;

Good potential for thermoelectric applications.

SLIDE 35

Bi doped Te Films Bi doped Te Films

d b d h l i i l

Many good Te-based thermoelectric materials;
S. Deng, J. K¨ohler and A. Simon, Physica C 460–462 (2007) 1020–

1021.

SLIDE 36

Low Te bulk thermal conductivity

(2.35 Wm-1K-1 [T=300 K ]).

Maximization of S2 σ

SLIDE 37

Prepared by evaporation and ion implantation;

Prepared by evaporation and ion implantation; some sample heat-treated. Analyzed by XRD SEM/EDS and RBS

Analyzed by XRD, SEM/EDS and RBS.

Tellurium

120 90 100 110

Lin (Cps)

60 70 80 20 30 40 50 10 20

2-Theta - Scale

20 30 40 50 60 70 80 90 10

01-072-6647 (N) - Tellurium - Te - Y: 50.00 % - d x by: 1. - WL: 1.5406 - Hexagonal - a 4.45800 - b 4.45800 - c 5.92500 - alpha 90.000 - beta 90.000 - gamma 120.000 - Primitive - P3121 (152) - 3 - 101.976 - I/Ic PD Operations: Import File: AG_DetScan_GI.raw - Type: 2Th alone - Start: 20.00000 ° - End: 100.00000 ° - Step: 0.02000 ° - Step time: 4.5 s - Temp.: 25 °C (Room) - Time Started: 12109 s - 2-Theta: 20.00000 ° - Theta: 1.50000 ° - Chi:

2 Theta Scale

SLIDE 38

SLIDE 39

15 2 15 2

standard θ =0º

)

8.57x10

15 Bi/cm 2, in 1200x10 15 Te/cm 2

2000 3000

standard, θinc=0º

(counts)

1000

Yield

260 280 300 320 340 360 380

Channel

SLIDE 40

2000 600 2000 600

Te film Bi 734 5x10

15

Te film Bi 735 1x10

16 16

1500 400

Te film Bi 735 2i-1x10

16

Te film Bi 735 TT200C Te film Bi 735 2i-1x10

16TT 200C

1000

µΩm)

Te film Te film Bi 734 5x10

15

Te film Bi 735 1x10

16

400

(µΩ

µΩm)

500

ρ ρ (µ

Te film Bi 735 2i-1x10

16

Te film Bi 735 TT200C Te film Bi 735 2i-1x10

16TT 200C

200

ρ ρ (

500 200 50 100 150 200 250 300

T (K)

50 100 150 200 250 300

T (K)

SLIDE 41

200

Pure Te film Te film Bi 734 5x10

15

Te film Bi 735 1x10

16

150

V/K)

Te film Bi 735 1x10 Te film Bi 735 2i-1x10

16

Te film Bi 735 HT 200C Te film Bi 735 2i-1x10

16 HT 200C

100

wer (µV

50

ermopo

50

The

50 100 150 200 250 300

T (K) T (K)

SLIDE 42

800 700 800 600

m)

400 500

K (µΩm

300 00

ρ300K

100 200 0.00E+000 5.00E+015 1.00E+016 1.50E+016 2.00E+016 100

Bi impl.

SLIDE 43

200 150

K)

100

(µV/K S300K

50 0.00E+000 5.00E+015 1.00E+016 1.50E+016 2.00E+016

Bi impl.

SLIDE 44

300 250 300 200

2m)

150

µW/K

2

100

S

2/ρ (µ

50

S

0.00E+000 5.00E+015 1.00E+016 1.50E+016 2.00E+016

Bi impl.

SLIDE 45

4 < S2/ρ < 264 (µWK-2m-1) Bi2Te3 ~4000 µWΚ−2m−1

SLIDE 46

Bi

4

.%)

2

entration (at Conce

50

50 100 150

Depth (nm) Depth (nm)

SLIDE 47

Fil t ρ S2/ Film type ρ300K (µΩm) Ea(meV) S300K(µV/K) S2/ρ (µWK-2m-1) Pure Te 738 56 187 47 Bi impl. 5x1015 28

188

1262 Bi impl. 1x1016 26

145

809 Bi impl 2x(1x1016) 55

29

15 Bi impl. 1x1016 ht 200 C 66 53 147 327

16

Bi impl 2x(1x1016) ht 200 C 152 50 172 194

Bi2Te3 ~4000 µWΚ−2

−2m−1 −1

SLIDE 48

Bi doped Te Films - Conclusions

Semiconductor and semimetal behavior;
Bi increases → Power factor first increases and

Bi increases → Power factor first increases and then decreases; M d t l hi h S b k l

Moderately high Seebeck values;
Medium resistivities;
Very low gap;
Good potential for thermoelectric applications.

SLIDE 49

Conclusions Conclusions

New systems;

y m ;

Semiconductor;

Gl f lfill t f th i t

Glasses fulfill most of the requirements;
Films for specific applications;
Optimization.

SLIDE 50

E.B. Lopes

Dep. Química, Instituto Tecnológico e Nuclear/CFMC-UL, P-2686-

953 Sacavém, Portugal

E. Alves, N.P. Barradas, N. Franco
Dep. Física, Instituto Tecnológico e Nuclear, P-2686-953 Sacavém,

p g Portugal E Alleno C Godart

E. Alleno, C. Godart

CNRS, LCMTR, 2/8 rue Henri Dunant, 94320 Thiais, France

SLIDE 51

A k l d t Acknowledgements

GRICES/CNRS 2007-2008;
COST P16;

A O A

NATO ARW grant;
FCT Portugal under contract nr
FCT, Portugal, under contract nr.

PTDC/QUI/65369/2006.

SLIDE 52

New approaches to thermoelectric materials materials

A.P. Gonçalves ç

Outline Outline

Introduction New Systems C d i l Conducting glasses Bi doped Te Films p Conclusions

ZT = S2Tσ/K

Efficiency or Coefficient of Performance maximization ZT

Performance maximization

M i i ti f S2 ( f t )

Maximization of S2 σ Maximization of S σ

Mi i i ti f K Minimization of K

Gl

Glasses

Conducting Glasses Conducting Glasses

Minimization of K Low Klat

Maximization of S2 σ

Metallic Glasses Metallic Glasses

4 T 1000 K

4 < T < 1000 K

0 < ⏐S⏐ < 5 µV/K

Nb Ni Sn Nb32Ni60Sn8

S l t li Splat cooling

S(300 K) = 1 1 µV/K S(300 K) = 1.1 µV/K

Semiconducting Glasses Semiconducting Glasses

Ge20Te80 - known glass Ge20Te80 known glass semiconductor; Quenching in ice water; Q g Tg = 428 K, Tc = 493.5 K [1];

,

S(300 K) = 960 µV/K S(300 K) = 960 µV/K, ρ(300 K) = 2.77x108 µΩ µΩm[2].

Ge20-xTe80-yMx+y ρ decrease? M = Ag, Cu [1,2] CuxGeyTez general compositions; C T T (T G ) Cu25T5Te70 (T = Si, Ga)

DTA

Tc

Tc

Tg

)

(µΩm)

T % Te %

)

(µΩm)

Ge % Ge %

)

(µΩm)

Cu %

V/K)

S (µV

Te %

V/K)

S (µV

Ge %

V/K)

S (µV

Cu %

K

(µW/K

S

Te %

) W/K

S

Ge %

m)

W/K

S

Cu %

Bi doped Te Films Bi doped Te Films

d b d h l i i l

(2.35 Wm-1K-1 [T=300 K ]).

Maximization of S2 σ

m)

Bi impl.

K)

(µV/K S300K

Bi impl.

S

S

Bi impl.

4 < S2/ρ < 264 (µWK-2m-1) Bi2Te3 ~4000 µWΚ−2m−1

Conclusions Conclusions

A k l d t Acknowledgements

A O A

PTDC/QUI/65369/2006.

Thank you for your attention