Cutting-Edge Nanomaterials for Energy: Solar Cell ∙ Li

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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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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

1 2 C y cl es

8 C yc le s

4 C yc le s

Ba re

η ( %)

0.4 0.5 0.6 0.7

16 Cycles

12 Cycles

8 Cycles

4 Cycles

Bare

η ( %)

ZnO Cycle Number

C u rren t D en si ty ( mA /c m 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)

E x te rna l Q ua nt um E ff ic ie nc y ( % )

Wavelength (nm)

400 450 500

0 1 2

8 Cycles

16 Cycles 4 Cycles

Wavelength (nm)

E n h a n ce m en t R a ti o

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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Type-II Heterojunction Nanorods for Solar Cells

Quantum Dots (0-D)

Nanorods (1-D) CdSe

e -

Linear (lHNRs) Core-Shell (cHNRs)

e - e -

Type-II Heterojunction Nanorods (HNRs)

Efficiency

cHNR@TiO 2 lHNR@TiO 2

lHNR@CdS/TiO 2

Electrode Property Modification Nanorod Morphology Tuning

Open pore structure for HNR infiltration Glass

FTO TiO 2

CdS Pretreatment for Improved Electron Transport

&

 S. Lee, + J. C. Flanagan, + J. Kang, J. Kim, M. Shim, and B. Park, Sci. Rep. (2015).

 S. Lee, + J. C. Flanagan, + B. Lee, T.

Hwang, J. Kim, B. Gil, M. Shim, and B.

Park, ACS Appl. Mater. Interfaces.

(2017).

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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 + , HC(NH 2 ) 2 + , Cs + , . . B: Pb 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 μ m 2 μ m

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 (H z -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

1.601.651.701.75

0 2 8 6 4

on TiO2 Blocking Layer

α

2 (10 7 cm -2)

1.564 eV

1.60 1.65 1.70 1.75

0 2 8 6 4

on TiO2Blocking Layer

α

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

α 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 η : 11.23%

C u rr en t D en si ty ( mA /c m

2

)

Voltage (V)

RXN 4 RXN 3 RXN 1 RXN 2

2 4 6 8 10 12

Initial 30 Days

E ff ici en cy η (%) N orm al ized η

0.9 1.0

RXN 4 RXN 3 RXN 1 RXN 2

RXN 4

RXN 3 RXN 1 RXN 2

20 μ m

20 μ m 20 μ m

20 μ m

 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

C o unt s

0.0 0.6 1.2 1.8 2.4 3.0 3.6

PbI

2

:MAI = 2:3 1.46 ± 0.04 µ m

Grain Size (µm) PbI

2

:MAI = 1:1

0.53 ± 0.01 µm

Grain Size Distribution

10 20 30 40

• PbI

2

∗ FTO

* (220) (310) *

PbI

2

:MAI = 1:1

Int ens it y ( a rb. uni t)

Scattering Angle 2 θ (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 η = 14.3%

C u rren t D en si ty ( mA /c m

2

)

Voltage (V) J-V Curve

Noise Spectroscopy Photocurrent Analysis

Conductive AFM

PbI

₂

:MAI = 1:1

PbI

₂

:MAI = 1:1

PbI

₂

:MAI = 2:3

PbI

₂

:MAI = 2:3

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- 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

Haze (%)

20 30

10 0

80 100 120

350 400 450 500

A ut oc or re la ti on L eng th ( nm )

HCl

Vertical Roughness (nm) Oxalic Acid

20

10

10 20 30 40

0 5 10 15 20 25

Sheet Resistance ( Ω / ) Oxalic Acid

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

HCl

H aze ( % )

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

^.(

τ

_x,

τ

_y)

Di st a n c e τ

y(µm)

0.0 0.20 0.40 0.60 0.80 1.001.0

Distance τ

x x

(µ 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 τ (nm)

C ( τ )

1/e

 Light trapping for thin-films solar cells.

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Electrode Materials for

Li-Ion Battery

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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 μ Li cat

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: 488]

 J. Cho, Y. J. Kim, and B. Park, Chem. Mater. 12, 3788 (2000). [Times Cited: 476]

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 ar ge C ap ac it y ( 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). [Times Cited: 282]

 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). [Times Cited: 469]

Bare LiCoO 2

AlPO 4 -Coated

LiCoO 2

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

 Self-assembly of TiO 2 (P25) and GO by electrostatic interactions.

 Conformal coating of RGO on the individual LTO grains during solid-state reaction (5TiO 2 → Li 4 Ti 5 O 12 , ( ∆𝑽𝑽 ≅ 𝟑𝟑𝟑𝟑𝟑 )).

 The graphene-wrapped LTO manifested an excellent specific capacity at a lithiation/delithiation of 10 C after 100 cycles.

 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)

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

Electrochemical Properties of RGO/LTO

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

C. Kim, S. O. Kim, and B. Park, Carbon (2017).

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Lithium-Air Battery: Promise and Challenges

 Hierarchically ordered porous (HOP) structure

 Black-TiO 2 (bTiO 2 )cathode

 Carbon-free electrode with high conductivity High theoretical energy density (≈ 3500 Wh kg -1 )

 J. Kang, J. Kim, S. Lee, S. Wi, C. Kim, S. Hyun, S.

Nam, Y. Park, and B. Park,

Adv. Energy Mater. (2017). [Front Cover]

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Oxidation and Reduction

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Nanoscale Control

- Compositions?

- Nanostructures?

- Mechanisms?

http://bp.snu.ac.kr

Solar Cell Li Battery

Future Nanomaterials for Energy

Luminescence

Catalyst

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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

Prof. Woo Young Ahn Seoul National 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. Joonhyeon Kang LG Chem

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

Dr. Sungun Wi Samsung Electronics

 M.S.

Jiwoo Ahn Samsung SDI

Sujin Byun LG Chem

Yoon Sang Cho The Korea Development Bank

Myungsuk Choi POSCO

Alumni

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Ten Recent Publications

h-index = 49

Title Journal

연도

SCI IF

From Nanostructural Evolution to Dynamic Interplay of Constituents:

Perspectives for Perovskite Solar Cells Adv. Mater. 2017 19.791

Route to Improving Photovoltaics Based on CdSe/CdSe x Te 1-x Type-II Heterojunction Nanorods: The Effect of Morphology and Cosensitization on

Carrier Recombination and Transport

ACS Appl. Mater.

Interfaces 2017 7.504

Insights on the Delithiation/Lithiation Reactions of

Li x Mn 0.8 Fe 0.2 PO 4 Mesocrystals in Li + Batteries by in-situ Techniques Nano Energy 2017 12.343

Breathable Carbon-Free Electrode: Black TiO 2 with

Hierarchically-Ordered Porous Structure for Stable Li-O 2 Battery Adv. Energy Mater. 2017 16.721

Synchrotron-Based X-Ray Absorption Spectroscopy for

the Electronic Structure of Li x Mn 0.8 Fe 0.2 PO 4 Mesocrystal in Li + Batteries Nano Energy 2017 12.343

Single-Layer Graphene-Wrapped Li 4 Ti 5 O 12 Anode with

Superior Lithium Storage Capability Carbon 2017 6.331

Evaluating the Optoelectronic Quality of Hybrid Perovskites by

Conductive Atomic Force Microscopy with Noise Spectroscopy ACS Appl. Mater.

Interfaces 2016 7.504

Investigation of Chlorine-Mediated Microstructural Evolution of

CH 3 NH 3 PbI 3 (Cl) Grains for High Optoelcectronic Responses Nano Energy 2016 12.343

Wrapping Strategy for SnO 2 with Porosity-Tuned Graphene for

High Rate Lithium-Anodic Performance Carbon 2015 6.331

Organic-Acid Texturing of Transparent Electrodes toward

Broadband Light Trapping in Thin-Film Solar Cells Nano Energy 2015 12.343

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Newspapers

http://bp.snu.ac.kr

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2017. 08. 29

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MRS Organizer

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International Meetings (MRS)

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Graduation of Members

*

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Homecoming Party

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What is My Goal?

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• ??2009/04/01 Safety or Research?

• Title + 그림 from BP homepage??

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