PDF Cutting-Edge Nanomaterials for Energy - Seoul National University

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Nanomaterials for Energy Group 1

Byungwoo Park

Nanomaterials for Energy Group

http://bp.snu.ac.kr

Cutting-Edge Nanomaterials for Energy:

Solar Cell ∙ Li + Battery

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2

Humanity’s Top Ten Problems for the Next 50 Years

1. ENERGY

2. WATER 3. FOOD

4. ENVIRONMENT 5. POVERTY

6. TERRORISM & WAR 7. DISEASE

8. EDUCATION 9. DEMOCRACY 10. POPULATION

2003 6.5 Billion People 2050 8-10 Billion People

Prof. R. E. Smalley (1943 – 2005)

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Nanomaterials for Energy Group 3

Nanoscale Control: Nanomaterials for Energy

Nanomaterials for Energy

Solar Cell

Li + Battery

Phosphor Fuel Cell

Water Pumping

Lighting Systems

Portable Devices

Electric Vehicles

Laptops

& Cell Phones

Household Energy Storage System

Portable Power Supply

Less Polluting Power Generation Transportation

Quantum Dot

LEDs LCD TVs

PDP

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4 http://foreconomicjustice.org/3989

?

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Semiconductor-Sensitized Solar Cells:

from Quantum Dots to Quantum Rods

DSSC SONY DSSC

KIST

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6

하나의 광자에 의한 다중 전자 생성 나노입자 크기조절을 통한 광흡수 조절

Nozik, Science (2011).

Advantages of Quantum-Dot-Sensitized Solar Cells

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양자점/전해질 계면처리



양자점의 전기화학적 안정성 확보



Core/Shell 및 불순물 첨가를 이용한 밴드갭 조절



양자점 → 전해질로의 광전하 재결합 억제

양자점 전해질

산화물나노전극

TCO TCO

TiO 2 QD

Cu 2 S

Core/Shell Structure

Suppression of Recombination: Coating of QD

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8

0.0 0.1 0.2 0.3 0.4 0.5

0 1 2 3 4

16 Cycles

12 Cycles 8 Cycles

4 Cycles Bare

0.4 0.5 0.6 0.7

16 Cycles

12 Cycles

8 Cycles

4 Cycles

Bare

 (%)

ZnO Cycle Number

Curre nt Dens it y ( mA/cm 2 )

Voltage (V)

• Recombination of carrier electrons is significantly diminished by the ZnO layer.

• Enhanced adsorption behavior of CdS quantum dot.

300 400 500 600 700

0 20 40 60

4.0 3.5 3.0 2.5 2.0

Photon Energy (eV)

External Q uantum Eff ici ency (%)

Wavelength (nm)

400 450 500

0 1 2

8 Cycles

16 Cycles 4 Cycles

Wavelength (nm)

Enhancement Ratio

4 Cycles

8 Cycles

16 Cycles Bare

ZnO Passivation on TiO 2 Electrode in QDSC

J-V

IPCE

 H. Choi, J. Kim, C. Nahm, C. Kim, S. Nam, J. Kang,

B. Lee, T. Hwang, S. Kang, D. J. Choi, Y.-H. Kim,

and B. Park, Nano Energy (2013).

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Surface Ligand of Nanorod

 Different ligands improve efficiency by affecting charge-transfer dynamics.

Polystyrene bead wt. %

Polystyrene Bead in TiO 2 Electrode

 Beads in electrode are burnt to leave pores.

 Rods go deeper through percolated pores.

1-Octanethiol (OT) Trioctylphosphine

oxide (TOPO)

Type-II Heterojunction Nanorods for Solar Cells

Type-II Band Offset

OT-CdSe/CdSe

_0.4

Te

_0.6

TOPO-CdSe/CdSe

_0.4

Te

_0.6

TOPO-CdSe/CdTe TOPO-CdSe

Composition Control of Nanorods

 Type-II band results faster charge separation.

OT-CdSe/CdSe

_0.4

Te

_0.6

in Porosity-Tuned TiO

₂

3.02 %

1.69 %

~25 nm

e

^-

 S. Lee, + J. C. Flanagan, + J. Kang, J. Kim, M. Shim,

and B. Park, Sci. Rep. (2015).

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10

Organo-Metal Halide Perovskite Solar Cells

B Site: Metal Cation A Site: Organic Cation

X Site: Anion

Y. Xiao* and Q. Meng* (Tianjin University), Chem. Commun. 50, 15239 (2014).

Transparent Conducting Oxide Electron Transporting Material Perovskite Absorption Layer

Hole Transporting Material Metal electrode

+

- e

-

h

⁺

Cell Architecture

ABX 3 Perovskite Unit Cell

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Power Conversion Efficiency of 22.1%

(from National Renewable Energy Laboratory)

10 µm

Perovskite as the Next Generation Photovoltaics

A: CH

₃

NH

₃⁺

, C

₂

H

₅

NH

₃⁺

, HC(NH

₂

)

₂⁺

, . .

B: Pb

²⁺

, Cs

²⁺

, Sn

²⁺

, . . X: I

^-

, Br

^-

, Cl

^-

, . .

ABX 3 Perovskite

CH 3 NH 3 PbI 3 (one-step)

10 µm

TCO ETL MAPbI

₃

HTL CE

1 μm 2 μm

Nanostructure control of organolead halides perovskite for performance improvement.

1 10 100 1000

10

^-5

10

^-4

10

^-3

10

^-2

MAPbI

₃

(Cl)

S / I

2

(Hz

-1

)

Frequency (Hz)

1/f MAPbI

₃

 T. Hwang, D. Cho, J. Kim, J. Kim, S. Lee, B. Lee, K. H. Kim, S. Hong, C. Kim, and B. Park, Nano Energy, 26, 91 (2016).

Wavelength (nm)

1.60 1.65 1.70 1.75

0 2 8 6 4

on TiO2Blocking Layer



2

(

107cm-2

)

1.564 eV

1.586 eV 1.586 eV

Photon Energy (eV)

PS:TiO

₂

= 1:2

2

700

780 760 740 720

0 8 6 4 10

1.582 eV

^{1.589 eV}



2

( 10

.7

cm

-2

) 1.596 eV

Photon Energy (eV)

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Mechanism Control in the Perovskite Solar Cells

0.0 0.2 0.4 0.6 0.8 1.0

0 10 20

Maximum   11.23%

Current D ensity ( mA/cm

2

)

Voltage (V) RXN 4

RXN 3 RXN 1 RXN 2

2 4 6 8 10 12

Initial 30 Days

Effic ie ncy    Normali ze d 

0.9 1.0

RXN 4 RXN 3 RXN 1 RXN 2

RXN 4

RXN 3 RXN 1 RXN 2

20 μm

20 μm 20 μm

20 μm

 J. Kim, T. Hwang, S. Lee, B. Lee, J. Kim, G. S. Jang, S. Nam, and B. Park, Sci. Rep. (2016).

RXN 1 RXN 2

RXN 3 RXN 4

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The Effects of Excess CH 3 NH 3 I on Perovskites

2 µm

Cou nts

0.0 0.6 1.2 1.8 2.4 3.0 3.6

PbI2:MAI = 2:3 1.46 0.04m

Grain Size



m) PbI

2

:MAI = 1:1

0.53

 

0.01



m

Grain Size Distribution

10 20 30 40



PbI2FTO

*(220) (310)*

PbI

2

:MAI = 1:1

Intensity (arb. unit)

Scattering Angle 2



degree)

PbI

2

:MAI = 2:3

(110)

 *

XRD

• Toluene dripping during spinning of the excess CH 3 NH 3 I containing precursor.

 Enlarged grain size and improved crystallinity with perfect film coverage.

Toluene Dripping in the Non-Stoichiometric Precursor

 B. Lee, S. Lee, D. Cho, J. Kim, T. Hwang, K. H. Kim, S. Hong, T. Moon, and B. Park, ACS Appl. Mater. Interfaces (2016).

2 µm

PbI 2 :MAI = 1:1 PbI

₂

:MAI = 2:3

2 µm

300 nm

Perovskite HTM Au

BL-TiO₂ FTO

0.0 0.2 0.4 0.6 0.8 1.0

0 5 10 15 20 25

PbI

2

:MAI = 1:1 PbI

2

:MAI = 2:3

Best   14.3%

C urrent D ensity ( mA/cm

2

)

Voltage (V)

J-V Curve

A Power Supply

BL-TiO

₂

FTO Perovskite

Light

e

^-

h

⁺

Laser Detector

0.0 0.2 0.4 0.6

Ph oto cu rr en t ( n A )

PbI

2

:CH

3

NH

3

I = 2:3

PbI

2

:CH

3

NH

3

I = 1:1

0 1 2 3

Grain Size (  m )

Noise Spectroscopy Photocurrent Analysis

100 1000

10

^-7

10

^-6

10

^-5

PbI

2

:CH

3

NH

3

I = 2:3 PbI

2

:CH

3

NH

3

I = 1:1

S / I

2

( Hz

-1

)

Frequency (Hz) Conductive AFM

PbI

₂

:MAI = 1:1

PbI

₂

:MAI = 1:1

PbI₂:MAI = 2:3 PbI₂:MAI = 2:3

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14

- Superior light scattering with maintaining transparency and resistance.

- Due to effective crater formation with less amount of overall vertical etching.

0.0 10 20 30 40 50 60 70 80 90 100

26.1   



 34.2   



 30. 3   / 

Haze (%)

20 30

10 0

80 100 120

350 400 450 500

Au tocor re lati on Length ( nm)

HCl

Vertical Roughness (nm) Oxalic Acid

20

10

10 20 30 40

0 5 10 15 20 25

Sheet Resistance (  /  ) Oxalic Acid

120 s 90 s 60 s 20 min 15 min 10 min

HCl

Haz e (%)

by HCl

1 μm by Organic Acid

Light Trapping by Surface-Textured ZnO Layer

Texturing by Organic Acid

1 μm

 W. Lee, T. Hwang, S. Lee, S.-Y. Lee, J. Kang, B. Lee, J. Kim, T. Moon, and B. Park, Nano Energy (2015).

-1.0 -0.5 0.0 0.5 1.0 -1.0

-0.5 0.0 0.5 1.0

C^.(

x,

y)

Distancey(m)

0.0 0.20 0.40 0.60 0.80 1.00 1.0

Distance x x

(



m)

y

x y 1 0.8 0.6 0.4 0.2 0

σ

_rms

= 103 ± 5 nm, a

_corr

= 460 ± 3 nm

0 200 400 600 800 1000 0.0

0.2 0.4 0.6 0.8 1.0

Distance



(nm)

C()

1/e

 Light trapping for thin-films solar cells.

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Electrode Materials for

Li-Ion Battery

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16

Discharge

Electrode Materials for Li-Ion Battery

e -

Cathode Anode

LUMO

HOMO Li +

Li + E g

Carbon Li 1-x CoO 2

ano

μ Li cat

μ Li

ELECTROLYTE

Electron

Energy Φ OC Φ

e -

# #

- Capacity (Volume + Mass) - Rate Capability

- Stability - Safety - Cost

Solution?

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 J. Cho, Y. J. Kim, T.-J. Kim, and B. Park, Angew. Chem. Int. Ed. 40, 3367 (2001). [Times Cited: 439]

 J. Cho, Y. J. Kim, and B. Park, Chem. Mater. 12, 3788 (2000). [Times Cited: 403]

0 10 20 30 40 50 60 70

100 120 140 160 180

SiO

2

Bare B

2

O

3

TiO

₂

Al

2

O

3

ZrO

₂

D is ch a rg e C a p a ci ty ( m A h /g )

Cycle Number

C rate = 0.5 C

 Improved electrochemical properties by nanoscale metal-oxide coating

Novel Electrochemistry by Nanoscale Coating

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Metal-Phosphate Nanoparticle-Coated LiCoO 2

AlPO 4 nanoparticles (~3 nm) embedded in the coating layer (~15 nm)

 J. Cho, Y.-W. Kim, B. Kim, J.-G. Lee, and B. Park Angew. Chem. Int. Ed. (2003).

 E. Kim, D. Son, T.-G. Kim, J. Cho, B. Park, K.-S. Ryu, and S.-H. Chang

Angew. Chem. Int. Ed. (2004).

 C. Kim, M. Noh, M. Choi, J. Cho, and B. Park Chem. Mater. (2005).

Bare LiCoO 2

AlPO 4 -Coated

LiCoO 2

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Graphene Wrapping on Single-Crystal Li 4 Ti 5 O 12

Grain growth of LTO within the graphene sheets:

~32% volume increase.

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Graphene-Wrapped Single-Crystal Li 4 Ti 5 O 12

 Y. Oh, + S. Nam, + S. Wi, J. Kang, T. Hwang, S. Lee, H. H. Park, J. Cabana, C. Kim, and B. Park

J. Mater. Chem. A (2014). [Inside Back Cover]

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Single-Layer Graphene Wrapping on LTO

1.8 wt. % G-LTO (Single Layer) 0.5 wt. % G-LTO

(Half Layer)

2.9 wt. % G-LTO (Three Layers)

0 10 20 30 40 50 60

0 40 80 120 160 200

1.8 wt. % G-LTO

2.9 wt. % G-LTO 0.5 wt. % G-LTO 5 C

1 C 10 C 30 C 0.5 C

Sp ec ific Cap aci ty (mA h g

-1

)

Cycle Number

0.5 C

Bare LTO

Sample D

_Li

– CV

(× 10 -13 cm 2 s -1 )

R

_ct

(Ω g)

Conductivity (× 10 -3 S cm -1 )

0.5 wt. % Graphene

(Half Layer) 1.37 0.17 0.19

1.8 wt. % Graphene

(Single Layer) 0.22 0.11 1.85

2.9 wt. % Graphene

(Three Layers) 0.11 0.16 9.49

 J. Kim, + K. E. Lee, + K. H. Kim, S. Wi, S. Lee, S. Nam,

C. Kim, S. O. Kim, and B. Park, Chem. Mater. (submitted).

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3-D Porous Graphene Wrapping on SnO 2

 S. Nam, S.-J. Yang, S. Lee, J. Kim, J. Kang, J.-Y. Oh,

C.-R. Park, T. Moon, K.-T. Lee, and B. Park, Carbon (2015).

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Micron-Sized 3-D Porous LiMn 0.8 Fe 0.2 PO 4 Aggregates

LiMn 0.8 Fe 0.2 PO 4 Nanocrystallite

Carbon Layer

Electrolyte Permeable Pore

500 nm

20 nm

Advantages of the Micron-Sized 3-D Porous LiMn 0.8 Fe 0.2 PO 4 /C Aggregates

- Good electronic contact.

- Short Li-diffusion length.

- High-rate capability by pores filled with electrolyte.

- High volumetric energy density.

 S. Wi, J. Kim, S. Lee, J. Kang, K. H. Kim, K. Park, K. Kim,

S. Nam, C. Kim, and B. Park, Electrochim. Acta (2016).

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Ultrathin ZrS 2 Nanodiscs

Nanodiscs with various lateral sizes

Highly functional as host materials where nanoscale size effects are significant.

 J.-T. Jang, S. Jeong, J.-W. Seo, M.-C. Kim, E. Sim, Y. Oh, S. Nam, B. Park, and J. Cheon, J. Am. Chem. Soc. (2011).

1 disc consists of 3 layers

(local equilibrium, magic number)

3 unit cells

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Lithium-Air Battery: Promise and Challenges

Major challenges of Li-O 2 batteries (Carbon-based cathode)

Li-ion and non-aqueous Li–O 2 cells

Peter G. Bruce, Nat. Mater. (2011)

3.8 V (325 Wh/kg) 2.96 V (3,505 Wh/kg)

 Electrode structure → Pore clogging (Li 2 O 2 )

 Chemical instability → Side reaction (Li 2 CO 3 )

Problems

 Lightweight electrodes with high conductivity

 Porous structures with structural robustness (surface area, pore size and distribution)

 Catalysts (OER/ORR)

 Combination of electrode and electrolyte

Strategies

 Review Paper: H. Woo, J. Kang, J. Kim, C. Kim, S. Nam, and B. Park, Electron. Mater. Lett. (2016).

Cycle

Capacit y ( m Ah /g) Cycle Life

Capacity (mAh/g)

Vol tag e (V)

Energy Efficiency

Capacity (mAh/g)

Vol tag e (V)

Capacity Improvement of

Electrochemical

Performance

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Oxidation and Reduction

(27)

Nanoscale

Interface Control

- Compositions?

- Nanostructures?

- Mechanisms?

http://bp.snu.ac.kr

Solar Cell Li Battery

Future Nanomaterials for Energy

Luminescence

Catalyst

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Saeromi Hong Seoul National University

Sun-Tae Hwang LG Electronics

Seonghyun Jin Samsung Electronics

Myunggoo Kang University of Michigan

Suji Kang Samsung Electro-Mechanics

Hoechang Kim SK Innovation

Hyemin Kim Y.P. Lee, Mock & Partners

Sungsoo Kim LG Chem

Dr. Taeseok Kim SunPower Corporation

Yumin Kim Samsung Electronics

Doyoung Lee LG. Philips LCD

Jin Sun Lee Samsung Electronics

Junhee Lee Samsung Display

Sangkeun Lee LG. Philips LCD

Sungjun Lee Seoul National University

Jungjin Park Seoul National University

Sungjin Shin LG Chem

 Research Assistants

Woo Young Ahn Ohio State University

Dr. Dae-Han Choi HRL Laboratoties

Seung-Chul Ha SENKO

Kyounghwan Hwang Judge

Sang Uk Hyun University of Toronto

Prof. Kisuk Kang Seoul National University Prof. Sung Hoon Kang Johns Hopkins University

Heekyung Lee STX Institute of Technology

Prof. Hyukjae (Jay) Lee Andong University

Sang-Min Lee LS Mtron

Joonhee Moon Seoul National University

Prof. Byungha Shin KAIST

Dr. Jae Wook Shin National Institute of Standards and Technology

Jun Wen University of Toronto

 Ph.D.

Dr. Donggi Ahn Samsung Electronics

Dr. Hongsik Choi Samsung Electro-Mechanics

Dr. Dae-Ryong Jung Samsung Advanced Institute of Technology

Dr. Byoungsoo Kim SKC

Dr. Chohui Kim Samsung Electronics

Prof. Chunjoong Kim Chungnam National University

Dr. Jae Ik Kim Samsung Display

Dr. Jongmin Kim Samsung Fine Chemicals

Dr. Tae-Gon Kim Samsung Advanced Institute of Technology

Dr. Tae-Joon Kim Samsung Electronics

Dr. Yong Jeong Kim KISTEP

Dr. Yongjo Kim Samsung Electronics

Dr. Byungjoo Lee JAFCO Investment Korea

Dr. Deok-Hyung (Doug) Lee AMD/IBM Alliance

Dr. Joon-Gon Lee Samsung Electronics

Dr. Seung-Yoon Lee LG Electronics

Dr. Woojin Lee Samsung Display

Dr. Changwoo Nahm Samsung Electronics

Dr. Seunghoon Nam Korea Institute of Machinery & Materials

Prof. Taeho Moon Dankook University

Dr. Jeongmin Oh Korea Technology Transfer Center

Dr. Yuhong Oh Samsung Electro-Mechanics

Dr. Yejun Park Samsung Electro-Mechanics

Dr. Dongyeon Son Ministry of Trade, Industry, and Energy

 M.S.

Jiwoo Ahn Samsung SDI

Sujin Byun LG Chem

Yoon Sang Cho The Korea Development Bank

Alumni

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Ten Selected Publications

Corresponding Author h-index = 46

Title Journal

연도

SCI IF Citation

Investigation of Chlorine-Mediated Microstructural Evolution of

CH

₃

NH

₃

PbI

₃

(Cl) Grains for High Optoelectronic Responses Nano Energy 2016 11.553

Solvent and Intermediate Phase as Boosters for

the Perovskite Transformation and Solar Cell Performance Sci. Rep. 2016 5.228

Integration of CdSe/CdSe

_x

Te

_1-x

Type-II Heterojunction Nanorods into

Hierarchically Porous TiO

₂

Electrode for Efficient Solar Energy Conversion Sci. Rep. 2015 5.228

Wrapping SnO

₂

with Porosity-Tuned Graphene as a Strategy for

High-Rate Performance in Lithium Battery Anodes Carbon 2015 6.198

Organic-Acid Texturing of Transparent Electrodes toward

Broadband Light Trapping in Thin-Film Solar Cells Nano Energy 2015 11.553

Critical Size of a Nano SnO

₂

Electrode for

Li-Secondary Battery Chem. Mater. 2005 9.407 444

A Mesoporous/Crystalline Composite Material Containing

Tin Phosphate for Use as the Anode in Lithium-Ion Batteries Angew. Chem. Int. Ed. 2004 11.709 132

A Breakthrough in the Safety of Lithium Secondary Batteries by Coating the

Cathode Material with AlPO

₄

Nanoparticles Angew. Chem. Int. Ed. 2003 11.709 250

LiCoO

₂

Cathode Material That Does Not Show a Phase Transition from

Hexagonal to Monoclinic Phase J. Electrochem. Soc. 2001 3.014 209

Zero-Strain Intercalation Cathode for Rechargeable Li-Ion Cell Angew. Chem. Int. Ed. 2001 11.709 439

Novel LiCoO

₂

Cathode Material with

Al

₂

O

₃

Coating for a Li-Ion Cell Chem. Mater. 2000 9.407 403

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30

Newspapers

http://bp.snu.ac.kr

동아 일보

2014. 02. 03

한국 경제

2012. 12. 27

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Nanomaterials for Energy Group 31

World Class University

(32)

32

MRS Organizer

(33)

International Meetings (MRS)

(34)

Graduation of Members

*

(35)

Homecoming Party

*

(36)

36

Teacher’s Day

(37)

House Party

(38)

38

Last Summer

(39)

(40)

40

What is My Goal?

(41)

• ??2009/04/01 Safety or Research?

• Title + 그림 from BP homepage??

(42)

42

(43)

Nanomaterials for Energy Group 43 Prof. Smalley’s Group

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