Nanostructured inorganic materials for energy

Delia Milliron Group

New phenomena at the nanoscale: Interfaces can dominate behavior

4 nm nanocrystal > 50% “surface”

nanocrystal-in-matrix > 80% “interface”

A B

additive function

A B

i

functional interface

NH2SH

Green manufacturing with nanomaterials

‣ Solution phase synthesis and processing

‣ Low temperature for low embodied energy

‣ Low cost for viable large area/scale devices

‣ smart windows, solar cells, batteries

Inorganic    Core

Organic  Ligands

6-

solvent dispersible nanocrystal

[Nb10O28]-6

water soluble POM

Nanocrystal-based materials and devices

Chemical control of nanocrystals

Tgrowth=210°C Tgrowth=220°C

Tgrowth=240°C Al-ZnO

PbSe

20 nm

20 nm

Fe3O4

Optical and structural

properties

Au

Au

10µm

Assembly and integration

Various%kind%of%solGgel%films%

•  Highly%transparent%

•  Thin%films%from%urea%combus+on%shows%highest%conduc+vity%

•  Combining%of%combus+on%solGgel%process%and%nanopar+cles%

–  Local%heat%may%induce%be]er%par+cle%connec+on%%

Before%N2%annealing%

AEer%N2%annealing%

Urea%

Combus+on%

Conven+onal%

method%

Acetylacetonate%

combus+on%

8.9%kΩ/sq% 15%kΩ/sq% 65%kΩ/sq%

4.9%kΩ/sq% 8.8%kΩ/sq% 20%kΩ/sq%

Semiconductor Nanocrystal Plasmonics

Tunable and responsive properties Application: Electrochromic windows

Interface-Mediated Transport Ion transport through pores and

composites Application: Fuel cell, battery

membranes

Nanocrystal Assembly and Integration

Polymer-nanocrystal assembly, gels Application: Sensors, electrochemical

devices

Phase Stability and Transitions Meta-stable phases and phase

switching materials Application: Thermochromic windows,

solar cells

5nm$

WZ 100

WZ 101

WZ 002

K 112

400℃

Electric field enhancement using plasmonic metal oxide nanocrystals

24.418.612.87.031.25Epol

Shape-dependent field-enhancement

Synthesis and Simulation of ICO Nanoparticle

X=0 X=L1 X=L2 X=L3

r Modeling and experiment on Electrochromic Device

Photonic Crystal Modeling

Research

Synthesis and Simulation of ICO Nanoparticle

X=0 X=L1 X=L2 X=L3

r Modeling and experiment on Electrochromic Device

Photonic Crystal Modeling

Research

309

232

155

77.3

.008

All are 10 nm-equivalent In-CdOAnkit Agrawal, et al., in press.

84.7

63.8

42.8

21.9

.930

Epol

Hot spots in dimers

Sample preparation

5

4 sizes each of CeO2 and TiO2

3 nm TiO2 6 nm

12 nm 12x30nm

2.8 nm CeO2 4 nm

6.3 nm 11 nm

range of pore sizes

Proton transport through microporous metal oxides

Measuring proton conductivity

7

1 cm

1 mm

sputtered Pt

ceria film

-3.0

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

6543210Zreal (x109 Ω)

Z imag

(x10

9 Ω)

Zresistor

= R

Zcapacitor

=1

j!CZinductor

= j!L

ZVoigt

=R

1 + j!RC

Measuring proton conductivity

7

1 cm

1 mm

sputtered Pt

ceria film

-3.0

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

6543210Zreal (x109 Ω)

Z imag

(x10

9 Ω)

Zresistor

= R

Zcapacitor

=1

j!CZinductor

= j!L

ZVoigt

=R

1 + j!RC

Conductivity of 4 nm CeO2 nanocrystal films

8

-5

-4

-3

-2

-1

log(

T·m

) [K·

S/cm

]

3.0x10-32.82.62.42.22.01.81.61.41/T (K)

50100150200250300350400450450Temperature (ºC)

0.74 eV

conductivity under dry Ar

0.51 eV

conductivity under wet Ar

-5

-4

-3

-2

-1

log(

T·m

) [K·

S/cm

]

3.0x10-32.82.62.42.22.01.81.61.41/T (K)

50100150200250300350400450450Temperature (ºC)

0.74 eV

conductivity under dry Ar

Typical electronic conduction behavior for nanocrystalline CeO2

Significant increase in conductivity already occurring at 300℃

-5

-4

-3

-2

-1

log(

T·m

) [K·

S/cm

]

3.0x10-32.82.62.42.22.01.81.61.41/T (K)

50100150200250300350400450450Temperature (ºC)

0.74 eV

conductivity under dry Ar

0.51 eV

conductivity under wet Ar previous literature values(wet Ar)

Enhanced proton (and electron) conductivity compared to previous work

50 nm

Evan Runnerstrom

H+

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