Organic Solar Cells

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How can we

provide sufficient,

affordable energy for

a growing world population?

Renewable energies: The potential of our sun

3 * Forecast of energy-mix according to potential

Total capacity of the sun 120.000 TW

36.000 TW on land

Global energy demand 2050*

28 TW

2 TW Hydro power

4 TW Wind power

6 TW Biomass

10 TW Geothermal

energy

6 TW missing

The sun provides almost infinite amounts of energy…

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0 50 100 150 200 250 300 350 W/m2

Source: Matthias Loster, 2006, Wikipedia

* Global energy demand 2006:14 TW Forecast for 2050: 28 TW

Insolation power on earth's surface

= ca. 900.000 km2 with solar cells of 8 % efficiency: 18 TW *

We are flooded with energy from the sun.

Can we put light into bags?

Yes, we can!

By converting it into electricity !

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Our competence:

1.

We investigate novel dyes

that lead to high power

conversion efficiencies.

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New NIR dyes harvest more light

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Wavelength [nm]

400 500 600 700 800

Normalized EQE / radiant power

Solar spectrum

ID1216 14 mA/cm²

ID504 10 mA/cm²

ID1216 has a potential power conversion efficiency of up to 12 %

New dyes are optimized for application in solar cell devices

Timeline of record efficiencies of different

thin-film technologies

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CIGS

CdTe

a-Si OPV

Development similar to inorganic thin- film technologies

Conversion efficiency (Lab) in %

Source: NREL 2010 et al.

Our competence:

2.

With our partners, we

develop highly efficient

OPV devices which

convert sunlight into

electricity.

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How does an organic solar cell work?

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Excited state

Ground state

Light energy

Voltage

Current = Number of converted photons

Electron transport

Hole transport

Our competence:

3.

Our devices are

manufactured by simple

coating processes.

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Example Solargate –

Transparent, flexible

integrated modules

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Organic solar cells can

be integrated into roofs,

facades, windows and

cars. 13

Roadmap for Organic Photovoltaics – OPV

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Consumer electronics, mobile solutions

2010

Local supply in rural areas, industrial applications

Cars, roofs, facades

2015

2020

Source of picture (middle of bottom section): Deutsche Solar

Organic photovoltaics is

a sustainable technology

because…

… the energy payback time of the installed modules is only a few weeks.

…the raw materials are cheap and almost unlimited.

… no heavy metals or rare-earth materials are necessary for production.

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Our challenges in the coming years:

The lifetime must be increased to 20 years.

Robust manufacturing techniques have to be developed.

The power conversion efficiency has to be improved to > 10% in modules.

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