25. juni 2008

Silicon thinfilm tandem technology and industrial production by Sunfilm

Carsten Rohr

9 Jan. 2008

25.06.2008

Norsun

• Incorporated in 2005 as a subsidiary of Scatec • Manufactures mono-crystalline ingots and wafers• Mission to become the global cost- and technology leader in mono-crystalline wafers

production by 2010 • Shareholders: Scatec, Good Energies, Norsk Hydro, and others

Polysilicon Wafer Cells Modules Systems

Sunfilm AG

Polysilicon projects

Strategic partners

Okmetic

Equipment suppliers

Strategic partners

Investments

Partners

25.06.2008

PV grid price parity outlook

Average residential & commercial power price (Germany)

Peak utility price(Germany)

Source: Solarbuzz 2006, Citigroup 06/2005

Assumptions5% solar cost decline p.a.2.5% price increase p.a. of electricity tariff

Utility prices and solar power generation cost (EUR/kWh) in Germany (sun energy 900KWh/year)

0.0

0.2

0.4

0.6

0.8

2005 2010 2015 2020 2025 2030 2035 2040

Residential competitive

Commercial competitive

Utility bulk power priceAverage industrial power priceAverage commercial power priceAverage residential power price

Commercial Solar production costIndustrial Solar production cost

Residential Solar production cost

Solar production cost Utility prices

Residential systems

Commercial systems

Grid parity in certain markets

Solar cell technologies

Source: ThinFilm Sun&Wind Energy 1/2007, PSE 2007

Production in 2006 (in MWp)

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

Solar Cell

Crystalline Si Wafer

Amorphous + µc Si

Thin Film

Concentrator (III - V)

Mono Crystalline

Multi Crystalline

Ribbon

CdTe

CIS

Other Chalcopyrites

GaAs

InP

Others

New Technologies

Dye Solar Cell

Organic Structures

Others

Thin Film Crystalline

880

1089

57

153

n.a.

57

9

n.a.

1 GWp0

90%

Thin film advantages

+ Cost

+ No resource constraints

+ Scaling

+ New applications

25.06.2008

Cell / module production outlook

Source: averages from UBS, GS, Photon, LBBW (update 08.11.2007).

2,1 2,5 3,75,7

8,9

0,2 0,61,2

2,0

2,8

3,5

14,5

02468

101214161820

2006 2007 2008 2009 2010 2011

Thin filmConventional PV

GW

Thin film at ~19% market

share

Thin film at ~10% market

share

2.3 3.14.9

7.7

13.1

2006-2011 CAGRConventional PV: 47%Thin film: 77%Total: 51%

18.0

25. juni 2008

Announced production capacity by thinfilm technology

Source: Status and Perspectives of Thin Film Solar Cell Production, A. Jäger-Waldau, European Commission, DG JRC, Ispra, 22nd EU PVSEC, Milan 2007.

25.06.2008

Markets recognize thin film potential

Thin film: First Solar

Integrated: SolarWorld, REC and Trina

Cell / module: SunPower, Suntech, Q-Cells, Motech, Solarfun, Canadian Solar, Aleo Solar & Solon

500

450

400

350

300

250

200

150

100

50Nov 06 Jan 07 Apr 07 Jun 07 Aug 07 Nov 07

Thin film: 363%

Integrated: 129%

Cell / module: 99%

Silicon feedstock: 46%

MSCI Utilities: 16%Conglomerates: -13%

Indexed to 100

Source: Morgan Stanley, November 2007

Silicon feedstock: MEMC, Tokuyama and Wacker

Conglomerates: Sharp, Kyocera, BP, Energy Conversion and Sanyo

Thin film offers clear advantages• High potential for cost reduction• Low material costs (1% of Si use vs. wafer based techs) and no major

silicon constraints• Higher energy yield at less optimal environmental conditions

(dawn, dusk, cloudy days)– Performance advantage in northern locations– Performance advantage in hot climates (better temperature coefficient)– Generates ~10% more energy (kWh) per Watt peak installed than

crystalline PV• Strong synergies with flat panel display industry (=> industrial production)

25. juni 2008

Silicon thin film technologies• Amorphous silicon

– ~ 6% efficiency– Long established,

well understood technology

– Flexible substrates possible

• Multi-junction amorphous silicon– 7-8% efficiency

• Better utilisation of solar spectrum

• a-Si/micro-crystalline Si tandem– ~ 8% efficiency

• prospect of 10%, and 12% in the longer term

25. juni 2008

Amorphous Top-Cell Microcrystalline Bottom-Cell

Spectral response of an a-Si/µc-Si tandem cell• Bandgap µc-Si: ~ 1.1 eV (1130 nm), Bandgap a-Si: ~ 1.6 – 1.75 eV (775 – 710 nm)• Better utilisation of the solar spectrum

a-Si:H

µc-Si:H

Wavelength in nm

Qua

ntum

effi

cien

cyin

%

UV VIS IR

Wavelength in µm

Spe

ctra

l rad

iatio

n de

nsity

in k

W /

m²µ

m

25. juni 2008

Structure of an a-Si/µc-Si tandem solar cell• Substrate: TCO (tranparent

conducting oxide) coated float glass• Absorber: amorphous und

microcrystalline Silicon (a-Si/µc-Si)• Back contact: TCO and metal• Protective layer: NiV• Encapsulation/Laminination: PVB• Back Glass

Glass

TCO (SnO2:F)

a-Si:H

μc-Si:H

PVB

Glass

Back Contact

Transparent Front Contact

Absorber

Encapsulation

25. juni 2008

Players in Silicon thinfilm PV• Equipment / technology

providers:– Applied Materials (USA)– Oerlikon (Switzerland)– Ulvac (Japan)

• Module manufacturers:– Kaneka (Japan)– Mitsubishi Heavy Industries (Japan)– Sharp (Japan)– Topray (China)– Brilliant 234 (Germany)– Sanyo (Japan)– Ersol (Germany)– Moser Baer (India)– T Solar Global (Spain)– Signet Solar (USA/India/Germany)– Sunfilm (Germany)– etc.

Applied Materials production line “Applied Sunfab”Quality

Deposition (TCO, back surface reflectors)

Junction Box Attach

Washing

Lasering

Lasering

Lamination

Back Glas

PECVD Deposition (Silicon layer)

Source: Applied Materials

25. juni 2008

PECVD - Plasma-enhanced chemical vapor deposition• Plasma to generate reactive

species via ionisation, dissociation and excitation

• Chemical reaction on heated substrate (~ 200°C)

• Process gases:• Silane (SiH4) and H2• TMB (Trimethylboran) for p-

doping• Phosphin (PH3) for n-doping

• Deposition rate• Influence on crystallinity

• Afterwards: • Cleaning with NF3• Purging with Ar

Silane

(SiH4)

Exhaust

RF-Generator (13.56 MHz)

Plasma

Diffuser

H2

Substrate Substrate heater

Electrode

25. juni 2008

PVD - Physical Vapor Deposition• Plasma to generate Ar+ ions• Low energy Ar+ ions are

accelerated to hit the target and thereby release atoms (sputter) which deposit on the substrate

• Sputter targets: metal, metal oxides

25. juni 2008

Front glassFront contact

Absorber

Back contact

Laser structuring for monolithic inter-connections• Integrated monolithic serial connection is a main advantage of thinfilm technology

• Low current and high voltage• Accurate positioning and temperature control required

• because of thermal expansion of the glass substrate

250 µm

10 mm

Sunfilm – Norsun investment in thin film

• based in Großröhrsdorf near Dresden (Germany) • first 60MWp factory is being built

• Construction started summer 2007 • Production expected to commence summer 2008• About 180 employees when fully operational

• Ambitious growth plans

Gen 8.5 Silicon thinfilm module• Size and flexibility• Low cost promise• Higher energy yield• Good aesthetics• Suited for Building

Integrated Photovoltaics (BIPV)

• No cadmium2.2

2.6

Gen 8.5

1.1

1.3

Gen 5

Monocrystalline Si module

Multicrystalline Si module

8% nominal 450Wp

Fab 1 currently under construction

Site Fab 1 purchased/ additional land blocked

Temporary offices

23km from Dresden

Gas farm and other expansion areas

May 2007

June 1, 2007 „ Groundbreaking“

August 12, 2007

August 20, 2007

November 8, 2007 „Topping“

November 26, 2007

25.06.2008

December 10, 2007

25.06.2008

January 4, 2008

Sunfilm contactsWolfgang Heinze, COO

Dr. Sicco W.T. Westra, CBDO

Dr. Wilhelm Stein, Head of Process Technology

David Metzger, Member of the Executive Board

Sunfilm AG

Strasse E, Nr 8

01900 Grossröhrsdorf

Tel +49 35952 280 000

Fax +49 35952 280 111

www.sunfilmsolar.com

Dr. Carsten Rohr, Business Development, NorSun AS, carsten.rohr@norsuncorp.no

www.norsuncorp.no