[PPT] - Tanujjal Bora Tanujjal Bora Examination Committee: Prof. Joydeep PowerPoint Presentation

SLIDE 1

Tanujjal Bora Tanujjal Bora Examination Committee:

Prof. Joydeep Dutta
Dr. Nitin Afzulpurkar
Dr. Weerakorn Ongsakul

g Microelectronics Microelectronics School of Engineering and Technology

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Introduction Lit t R i Literature Review Methodology Results and Discussion Conclusions Conclusions

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SLIDE 3

Energy Sources Nonrenewable

Oil

Renewable

Wind
Coal
Natural Gas
Biomass
Solar

Why Solar Why Solar Energy?

Abundant

Available ~ 86,000 TW/y World Consumption ~ 15 TW/y

Never Ending

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Never Ending

SLIDE 4

Photovoltaic Effect – Invented by Edmund Becquerel in1839 1st Solar Cell was made in 1883 by Charles Fritts using Selenium 1 Solar Cell was made in 1883 by Charles Fritts using Selenium In 1954 – Commercial Solar Cell based on Single Silicon Crystal

1st Generation Single Layer 2nd Generation Multi Layer 3rd Generation Thin Film 4th Generation Polymer & Multi g y PN Junction

Monocrystalline

Si PN Junction

Polycrystalline

Si Solar Cell

Dye Sensitized

Solar Cell Polymer & Multi Junction Solar Cell Si Si

Amorphous Si
CIGS
CdTe

Solar Cell

Organic Polymer

Solar Cell

Quantum Dot

4

GaAs

Solar Cell

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Invented by Michael Grätzel & Brian O’Regan in 1990 at EPFL, Switzerland

5

y g

Simple to Fabricate
Low Cost of Manufacturing

SLIDE 6

Photoelectrode (PE) Dye Molecules Counter Electrode (CE) Electrolyte

Electrolyte (I-/I3

)

Dye Molecule Counter Electrode (+)

3

Pt Catalyst

6 Photo Electrode (‐) Metal Oxide Semiconductor (TiO2/ZnO/SnO2)

SLIDE 7

Similar to Natural Photosynthesis H2O + CH2O + O2

e‐ e‐ CB S+ e‐ LUMO e- e- e-

CO2

EF S/S*

Maximum Voltage Ox/Re Redox‐Couple

Energy EF e‐ e e‐ hν Chlorophyll VB h+ S/S

Dye

p

hν hν HOMO Electron Acceptor Electron Donor 7 hν hν

Back- Contact

Semiconductor Hole Conducting Medium Counter Electrode

SLIDE 8

Higher Surface Area => Higher Dye Adsorption

e e e e

Poro s Thin Film Charge Hopping

Zinc Oxide Thin Film

e

e
e
e
e
Porous Thin Film

g pp g

e- e- e- e- e- e-

Nanorods Direct Path

Zinc Oxide Nanorod

Nano < 100 nm

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Maximum DSSC Photoelectrode Material Structure Synthesis Method Type of Dye used Maximum DSSC Efficiency Reported (%) ZnO Porous Thin Film Spin Coating N719 5 Film ZnO Nanowire Hydrothermal N3 2.4 ZnO Branched Nanowire MOCVD N719 1.1 Nanowire ZnO Mixture of Nanoparticle and Nanorods Hydrothermal Mercurochrome 3.2 ZnO Nanosheets Spray Pyrolysis N719 3 9 ZnO Nanosheets Spray Pyrolysis N719 3.9 ZnO Nanotube CVD + Pyrolysis N719 4.6 9

K. Keis, C. Bauer, G. Boschloo, A. Hagfeldt, K. Westermark, H. Rensmo, H. Siegbahn. Journal of Photochemistry and Photobiology A: Chemistry 2002;148(1‐3):57‐64.
M. Guo, P. Diao, X. Wang, S. Cai. Journal of Solid State Chemistry 2005;178(10):3210‐3215.
K. Kakiuchi, E. Hosono, S. Fujihara. Journal of Photochemistry and Photobiology A: Chemistry 2006;179(1‐2):81‐86.
C. H. Ku, J. J. Wu. Nanotechnology 2007;18(50)
J. B. Baxter, E. S. Aydil. Solar Energy Materials and Solar Cells 2006;90(5):607-622
E. Hosono, S. Fujihara, I. Honma, H. Zhou. Advanced Materials 2005;17(17):2091-2094

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Construct ZnO Nanorods based DSSC

Improve Electron Conduction

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SLIDE 11

Hydrothermal Growth of ZnO Nanorods

Anisotropic Agglomeration

1μm

f ZnO Nanorods

Seeds

Zi it t h i Zinc nitrate + hexamine

Zinc nitrate + hexamine at 90⁰C Annealed at 350oC for 1 Hour

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A. Sugunan, H. C. Warad, M. Boman , J. Dutta, Journal of Sol-Gel Science and Technology, vol. 39, no. 1 SPEC. ISS., pp. 49-56, 2006.
S. Baruah, and J. Dutta, Science and Technology of Advanced Materials, vol. 10, no. 013001, pp. 18pp, 2009.
S. Baruah, and J. Dutta, Journal of Crystal Growth, vol. in press, 2009.

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Simple Simple Ease of Fabrication Low Cost Low Cost

Electrolyte Surlyn Counter Electrode

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Photoelectrode Counter Electrode

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Absorption Spectra of Dye on ZnO NRs at various Sensitization Time

1.4 1 hours 2 hours

Normalized Adsorption of Dye on ZnO Nanorods at various Dye Sensitization Times

nm

2 3.0

rbance

0.6 0.8 1.0 1.2 2 hours 3 hours 4 hours 5 hours 10 hours 20 hours 24 hours 48 hours 72 h

rption at λ = 580 n

1.5 2.0 2.5

Abso

0.0 0.2 0.4 72 hours

Normalized Adso

0.5 1.0

Maximum Dye Adsorption

Wave Length (nm)

300 400 500 600 700 800 900

0.2

Sensitization Time (Hours)

20 40 60 80 0.0

Ma im m Light Absorption 24 Ho rs

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Maximum Light Absorption = 24 Hours

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Nonhierarchical Hierarchical Nonhierarchical Growth Hierarchical Growth

ZnO Nanorods from Secondary Growth ZnO Nanorods from Primary Growth y Conducting Glass (FTO) Conducting Glass (FTO)

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1 µm 1 µm

SLIDE 15

20 mM 10 Hours

Variation in Surface Area of the ZnO Nanorod Photoelectrode with Precursor Concentration and Growth Time

Maximum SA = 483.47 cm2 20 M

1 µm 300 400 500 600

Area (cm

2)

10 mM 15 mM 20 mM 25 mM 30 mM

20 mM 40 Hours

1 µm 100 200 300 60 80 100 120 25 30

Surface A t h T i m e ( H

u

r s ) P

20 mM

20 40 5 10 15 20 25

T

t

a l G r

w

t h Precursor Concentration (mM)

15

60 Hours

1 µm

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Variation in Short Circuit Current Density (JSC) of the DSSC with increasing Surface Area of the Photoelectrode g

1 5 2.0 2.5

JSC (mA/cm2)

0.5 1.0 1.5 100 200 300 400 500 0.0

Surface Area (cm2)

Surface Area Short Circuit Current (J )

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Surface Area Short Circuit Current (Jsc)

SLIDE 17

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DSSC IV Characteristics

Jsc

FF = Maximum Power Theoretical Power

sity (mA/cm2)

6 8 Voc = 0.67 V Jsc = 11 mA/cm2 FF = 72.40% η = 5.34%

= Imax X Vmax Isc X Voc X 100%

Current Dens

4 6

η = Maximum Power In put Power

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 2 Active Area 0.09 cm2 Voc

In put Power = Isc X Voc X FF Pin %

17 Voltage (V) in

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LUMO of Dye e- e- CBZnO LUMO of Dye HOMO of Dye SPR level

f Au

h+ e- e-

Better Charge Separation Low Dielectric Constant

h

cm2)

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Active Area = 0.09 cm2

Gold Nanoparticle

t Density, JSC (mA/

8 10 12

VOC = 0.67 V JSC = 11 mA/cm2 FF = 72.40 %

hort Circuit Current

2 4 6 With Au Nanoparticles Without Au Nanoparticles

% η = 5.34 % VOC = 0.67 V JSC = 14.89 mA/cm2 FF = 65.06 % η = 6.49 %

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Voltage (V)

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

S

SLIDE 19

I k J t P i t d Sil (A ) G id Li th C t El t d Ink Jet Printed Silver (Ag) Grid Lines on the Counter Electrode Silver Grid Lines

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SLIDE 20

DSSC I-V Characteristics with and without Ag grid lines

)

2.5

Active Area = 1 cm2 V 0 62V

nt Density (mA/cm2)

1 0 1.5 2.0

VOC = 0.62V JSC = 2.3 mA/cm2 FF = 45.06 % η = 0.64 % Active Area = 1 cm2 VOC = 0.52 V JSC = 2.14 mA/cm2 FF = 39.82 %

Photocurren

0 0 0.5 1.0 With Ag grid lines Without Ag grid lines

η = 0.44 %

Voltage (V)

0.0 0.2 0.4 0.6 0.0

Sheet Resistance Fill Factor

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Sheet Resistance Fill Factor

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DSSC Efficiency at Optimum ZnO Nanorod growth condition is 5.34% Using Gold (Au) Nanoparticles, DSSC Efficiency is 6.49% Ink Jet Printed Silver (Ag) Grid Lines can Improve Fill Factor

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Prof. Joydeep Dutta for his continuous Guidance, Valuable Suggestions and

Encouragements

Dr. Nitin Afzulpurkar and Dr. Weerakorn Ongsakul for their Valuable Advices and

Supports Supports Sincere Gratitude to all the AIT Nano Lab Members – Mr. S. Baruah, Mr. R. Kitsomboonloha, Mr. Myo Myint Tay Zar, Md. Abbas Mahmood, Mrs. I. Baruah – f th i H l d S ti for their Help and Suggestions Special Homage to My Family and Friends for their Love, Support and Sacrifices