scaling of dye solar cells: from single cells to modules and panels stefano penna, riccardo...

Scaling of Dye Solar Cells: from single cells to modules and panels

Stefano Penna, Riccardo Riccitelli, Eleonora Petrolati,

Andrea Reale, Thomas M. Brown, Aldo Di Carlo

Centre for Hybrid and Organic Solar Energy (CHOSE)

Department of Electronic Engineering, University of Rome “Tor Vergata”

PLMCN10, Cuernavaca (Mex) 12-16 April, 2010

PLMCN10, Cuernavaca (MEX) 12-16 April, 2010

Outline

• Introduction to Dye Solar Cells

• Optimization strategies for efficiency improvement

• Upscaling: from DSC test cells to modules and panels

• Conclusions


Centre for Hybrid and Organic Solar Energy

• Set in 2007 upon Lazio Region 3-year funding

– 600 m2 lab facilities in the Hi-Tech District of Rome (Tecnopolo Tiburtino)

– 50 people: 5 Prof, 5 Assistant Prof, 9 Post Doc, 20 PhD, 11 post-grad

• Totally focused on Organic and Hybrid Photovoltaic technologies

– Materials– Processing towards inline

automation– Up-scaling towards large area

devices– Modeling and simulation tools• Technological Transfer to industry– Two spin-off companies hosted

– Dyers for technology development– TiberCAD for modeling

– Industrial partnership within Dyepower

51%

CHOSE

http://www.tiberlab.org http://www.dyers.it


Structure of a DSC

Dye Molecules on TiO2

Glass Substrate

Electrolyte I-/I-3

Catalyst (Platinum, graphite)

Glass Substrate

Transparent Conducting Oxide (FTO)

Transparent Conducting Oxide (FTO)

nanostructured TiO2


Working principle of a DSC

I3-I-Red

No permanent chemical transformation in the materials composing the cell

2S+ + 3I- 2S + I3- I3

- + 2e- 3I-S + hv S* S* S+ + e−(TiO2)

Titania (10 m) Dye Electrolyte (50 m) Catalyst (10 nm)


Unique aesthetical features

Colour tuning, Transparency Customized patterning


“New” manufacturing process

High temperature, doping, vacuum pocessing

Conventional Electronics Organic Electronics

Printing methodsConventional semiconductor

industry

Large enterprises(tens of M€ fab)

Small Medium enterprises (some M€ fab)

Liquid deposition


Other advantages of DSC technology

• Lower fabrication cost than Silicon PV– In DSC cost imposed by processing– In Silicon PV 80% cost imposed by silicon wafer production

• Ideal for Building Integration– Indipendent on lighting angle– Better working under scattered light than direct light– Availability for transparency, colour tuning, customized

patterning

• Higher energy produced during 1 year than Silicon PV upon the same Wp installed, despite lower Wp efficiency (11% vs 25% on lab cells)

• Lower fab cost lower entrance barrier for investors• Lower energy payback• High environmental compatibility


Optimization parameters

TiO2

Electrolyte

Counter-Electrode

EncapsulationLayout

Printing Technique

Dye

Easy

Medium

Critical

Difficult

Dyes

Natural Dyes

Industrial Dyes

Organic Dyes

Rutenium-Based Dyes

Efficiency

1%

11%

N719 Dye


Dye management

Spectral response can be enlarged by a double-dye strategy involving an IR absorber beyond the green absorber (N719 and similar)

400 450 500 550 600 650 700 7500,0

0,3

0,6

0,9

1,2

1,5

Ab

sorb

an

ce (

a.u

.)

Wavelength (nm)

N719 Near IR dye N719 : Near IR Dye

400 440 480 520 560 600 640 680 7200

10

20

30

40

50

(nm)

IPC

E (

%)

Colonna, Di Carlo, Bignozzi, Brown, Reale et al., under submission

Absorbance External Quantum Efficiency


TiO2 management: standard performance


TiO2 management

Tayloring the TiO2 surface by the use of Scattering Layers (SLs) to trap light in the working electrode

D. Colonna et al. / Superlattices and Microstructures 47 (2010) 197201

400 450 500 550 600 650 700 750 8000,00

0,15

0,30

0,45

0,60

0,75

Abs

orba

nce

(a.u

.)

Wavelength (nm)

TiO2 + N719

(TiO2+SL) + N719

enhanced subtended area

0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8

-20-18-16-14-12-10-8-6-4-20

ISC = 19.8 mA/cm2; Area = 0.25 cm

2

VOC = 747 mV; FF = 67.87 %

= 10.03 %

J [m

A/c

m2]

V [V]

+ 22.5%

S. Ito et al., Adv. Mater. 2006, 18, 1202–1205


Upscaling: from test cells to modules

• In a test cell performances are ruled by materials• In large area cells and modules performances are ruled by

technology– large area deposition– sealing and encapsulation– high series resistance of TCO electrodes (8 sq)

interconnections among cells needed

Test cell (0.5 x 0.5 cm2)Module 10 x 20 cm2


Module lay-outZ-configuration

– series connection– ideal for BIPV– interconnection dispensing is

critical

W-configuration– series connection– no need for interconnection

dispensing– not good for BIPV– problem with electrical

balancing

P-configuration– parallel connection– grid dispensing is less critical

+

+

+

Pictures courtesy of


Module performance

• Micro vertical interconnections (20 micron) for high level of transparency

Micro-interconnections (Z)

0,0 0,5 1,0 1,5 2,0 2,5 3,0

-120

-100

-80

-60

-40

-20

0

1.0 sun eff.= 3.5 %

0.6 sun eff.= 4.7 %

I [m

A]

V[V]

0.3 sun eff.= 5.7 %

37 cm2 module with 4 Z micro-interconnected cells (cell area = 9.4 cm2).


Large area: from modules to panels

Panel 0.8 x 0.6 m2

Module 20 x 10 cm2


String assembly: the beginning


Panel lay-out

20 Modules: 4 strings of 5 Modules Series Interconnected

Panels 0.8 x 0.6 = 0.48 m2

First DSC panel @ CHOSE


Strings composition

- + - + - +

Series interconnected DSC module Nickel conducting paste


DSC Strings performance

• Higher current production in Z strings• Higher voltage in W strings (one cell more per module)• Better fitting in W strings

0 5 10 15 20 25

-200

-150

-100

-50

0

Cur

rent

den

sity

(m

A/c

m2 )

Voltage (V)

I(Stringa 1 Z_Dyepower) I(Stringa_1(Pmax)) simulated

0 5 10 15 20 25 30-140

-120

-100

-80

-60

-40

-20

0

Cu

rre

nt

de

nsi

ty (

mA

/cm

2 )

Voltage (V)

I(Stringa 4) simulated I(Stringa 4)

+

+

Z-type W-type

= 5.03 % = 3.34 %


Panel assembly

Strings are aligned on a glass slab, protected by soldering bypass diodes (one per module) and parallel connected by bus bar

Glass lamination and Silicone filling for protection, UV filtering and higher resistance to environmental and mechanical stress


The result


Panels performance

• Outdoor testing at 1 sun (1000 W/m2)• Panel perpendicular at sun light

0 5 10 15 20 25 30 350,0

0,1

0,2

0,3

0,4

0,5

Voltage (V)

Cur

rent

den

sity

(m

A/c

m2)

W type panel

0

2

4

6

8

Efficiencyactive area: 3.2%total area: 1.72%

Pow

er (mW

)

Max power 6,88 W @ 19.68 V

0 5 10 15 20 25 300,0

0,2

0,4

0,6

0,8

Voltage (V)C

urre

nt d

ensi

ty (m

A/c

m2 )

0

2

4

6

8

10

Efficiencyactive area: 4.42%total area: 2.38%

Pow

er (W)

Max power: 9.5 W @15.7 V

Z type panel


PV CELL

Traditional Photovoltaic Applications

25


Innovative PV applications


CHOSE within Dyepower Consortium

• 10 M€ framework agreement for the industrialization of DSC based continous glass envelopes for real BIPV

• Transparency and aesthetics have primary roles in the development step

• Automation purposed approach as afundamental guide line

http://www.permasteelisa.it/


Conclusions

• Upscaling from cell to module is not trivial, but proper engineering on modules lay-out and deposition technologies can reduce the drop of efficiency

• Final upscaling from module to string and panel is less difficult, even if additional aesthetical issues must be considered

• Final target of 5% efficiency on DSC panel is not far

• Long term stability is the last hurdle for commercialization …

… but we’re workin on it !


AcknowledgmentsCollaborators:• Univ. Ferrara, Chemistry Dep. (Prof. Bebo Bignozzi)• Sapienza Univ. Rome, Energy Dep. (Prof. Michelotti, Dr. Dominici)• Sapienza Univ. Rome, Chemistry Dep. (Prof. Decker)• Univ. Rome Tor Vergata, Physics Dep. (Maestro Pino Eramo)• Univ. Turin, Chemistry Dep. (Prof. Viscardi)• Regione Puglia, Ass. “Nessuno Tocchi Raffaele”• Univ. Sevilla, (Prof. Colodrero)

All people @ CHOSE, special thanks to:

• Daniele Colonna• Alessandro Lanuti• Simone Mastroianni• Lorenzo Dominici

http://www.chose.it/

scaling of dye solar cells: from single cells to modules and panels stefano penna, riccardo...

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