advances in thin film pv: cigs & cdte - les pages … · advances in thin film pv: cigs &...

Swiss Federal Laboratories for Materials Science and Technology

Advances in Thin Film PV: CIGS & CdTe

Laboratory for Thin Films and Photovoltaics Empa- Swiss Federal Laboratories for Material Science and Technology

Dübendorf, Switzerland

Acknowledgments R&D Group Members at EMPA and Staff of Flisom AG Swiss Federal Office of Energy (SFOE) Commission for Technology and Innovation (CTI) Swiss National Science Foundation (SNSF) FP7-EU Framework Program

Ayodhya Nath Tiwari

Laboratory for Thin Films and Photovoltaics

Contributions of Empa team: Adrian Chirilă, Patrick Reinhard, Fabian Pianezzi, Patrick Bloesch, Alexander R. Uhl,

Carolin Fella, Lukas Kranz, Debora Keller, Christina Gretener, Harald Hagendorfer, Dominik Jaeger, Melanie Werner, Rolf Erni, Shiro Nishiwaki, Yaroslav Romanyuk, Julian Perrenoud, Stephan Buecheler

Towards high efficiency and cost reduction concepts

Si wafer

III-V on wafers

Thin film Si

a-Si

CIGS CdTe

DSC OPV

Different technologies Several options available Different opportunities and levels of maturity

CZTS

Swiss Federal Laboratories for Materials Science and Technology Laboratory for Thin Films and Photovoltaics

Thin film solar cells based on compound semiconductor absorbers: CIGS and CdTe

High efficiency potential to 30%

Long term performance stability

Cost effective process and materials

Low cost solar modules

Sunlight

Back contact

TCO

CdTe

CdS

Transparent substrate

Sunlight

Substrate

Back contact

TCO

CIGS

Buffer

Deposition order Deposition order


Towards cost effective solar electricity with thin film PV

High efficiency and stability

Low production cost of solar modules

Low Capex factories

Integration and implementation

Low BOS cost

Dead-end or progress in right direction?


CIGS and CdTe thin film photovoltaics


High efficiency: 19.6% - 20.4% cells 15.7% - 16.1% champion modules Low cost: Inherent advantages of thin film

technology for large area high speed coating and monolithic

interconnections

Alraedy proven by First Solar (CdTe)

Solar module cost < $0.50/Wp and fully installed system cost < $1/Wp seem feasible

Advantages on integration on system level and provisions of added functionalities (e.g. BIPV)

Excellent progress made and it continues....

Swiss Federal Laboratories for Materials Science and Technology Laboratory for Thin Films and Photovoltaics Swiss Federal Laboratories for Material Science and Technology

Source: http://www.nrel.gov/ncpv/images/efficiency_chart.jpg

20.4% flexible CIGS solar cell record by Empa

Swiss Federal Laboratories for Materials Science and Technology Laboratory for Thin Films and Photovoltaics Swiss Federal Laboratories for Material Science and Technology

Key issues in high efficiency CIGS solar cells

1µm Substrate

Mo

CIGS

Buffer ZnO/ZnO:Al

15 20 25 30

100

300

500

700

900

Cu [at%]

t [°C

]

α

α

α+β

α+δ

δ

β

β+δ

δ

α+Cu2Se (HT)

α+Cu2Se

Cu-poor composition below stoichiometry point

Interface phases

Ga gradient –> band gap gradient

- Morphology (surfaces and interfaces) - Microstructure and defects - Stress - Composition gradients - Doping with Na

Swiss Federal Laboratories for Materials Science and Technology Laboratory for Thin Films and Photovoltaics 8

Source: http://www.solar-frontier.com/eng/news/2013/C014763.html and other websites

… achieves 19.7% efficiency solar cell (0.5 cm2) … completed a new 900MW module factory producing 13% efficiency solar panels … posted revenue of $833 million in 2012 and recorded its first positive quarterly income in the fourth quarter … achieves 14.6% efficiency champion solar module (1257mm x 977mm) at 179.8W (June 2013)

CIGS on glass substrate gaining maturity for large volume industrial production

News of success from Solar Frontier:

http://www.solar-frontier.com/eng/news/2013/C020760.html





CIGS technology on glass substrates has progressed to industrial scale production

(Several papers presented during the conference)


BOSCH Honda

Flexible CIGS technology is in early stage of development (pilot-scale production)

http://www.heliovolt.net/index.php


Thin film solar modules: Glass vs foil

3 mm Glass

3 mm Glass

~ 200 mm

Solar cell thickness ~ 4 µm

Modules on foils: Flexible Lightweight

Flexible and lightweight solar modules offer several advantages and paradigm shift

Laboratory for Thin Films and Photovoltaics Swiss Federal Laboratories for Material Science and Technology

Mature technology Emerging technology


http://www.solopower.com

SoloPower

http://www.ascentsolar.com

http://www.globalsolar.com

http://www.flisom.ch

http://www.solarion.net

http://www.miasole.com

Ascent Solar

Sorry for missing names…

DNP

Solarion

Companies in development stage (pilo-scale)...

http://www.globalsolar.com/

http://www.miasole.com/

http://www.fujifilm.com/


Progress: 20.4% efficiency Improvement in record efficiency of flexible solar cells

Lift-off process Spin-coated PI and NaCl

20.4%

Post-deposition Na

Excellent potential to bring a paradigm shift as efficiency equals to Poly-Si wafer and CIGS/glass record values



Potential of CIGS technology


20.4% efficiency of CIGS solar cells on glass and flexible polymer matches to poly-silicon wafer solar cell

Prospects of 25% efficiency CIGS solar cells are bright ! Higher efficiency with tandem and concentration concepts


Technology status: Industrial manufacturing Selected examples (disclaimer: not a complete or updated list, discretion is used)


Vacuum-based (Co-evaporation)

See also: Solarion Ascent Solar Flisom XsunX, etc…

See also: NuvoSun Honda Soltec Midsummer Bosch CIStech,

etc…

Non vacuum-based precursor and selenization/sulfurization

See also : Heliovolt ISET, etc…

Vacuum-based precursor and selenization/sulfurization

Glass 17.4% submodule 14.7% module Monolithic

Stainless steel 13.2%

submodule Stringing

Glass 15.9% lmodule Monolithic

More details: P. Reinhard et al., Technological status of Cu(In,Ga)(Se,S)2-based photovoltaics, SOLMAT (2013), http://dx.doi.org/10.1016/j.solmat.2013.08.030

Glass 19.7% cell 17.8% submodule Zn(O,S) buffer

Glass 15.7% module Glass

15.8% module Stainless steel 15.7% module Roll-to-roll All-sputtering process

Glass Electrodeposition 14.2% (AA) submodule

Stainless steel Electrodeposition 13.4% module

Coated aluminium Printing 17.1% cell

Champion efficiencies

Large size modules: 15.5% - 15.9%

Sub-modules: 17.4% - 17.8%

Continuous trend of remarkable progress in average

efficiency of modules in industrial production is reported

18% module efficiency in near future….

BOSCH Glass 15.1% (AA) module

15

Deposition order


CdTe device structure

19.6% cell efficiency (GE)

Green et al., PiP 21, 827 (2013)

19.0% cell efficiency (FSLR) Gloeckler et al., IEEE J. PV 3, 1389 (2013)

16.1% module efficiency (FSLR) http://investor.firstsolar.com/releasedetail.cfm?ReleaseID=755244

17-18% projected module efficiency (FSLR) Gloeckler et al., IEEE J. PV 3, 1389 (2013)

Costs: 0.68 $/Wp (FSLR)

13.6% efficiency (Empa)

Kranz et al., Nature Commun. 4, 2306 (2013)

11.0% efficiency (NREL) Dhere et al., Proc. IEEE PV Specialists Conf. (2012)

Conventional configuration ~ 2000 publications

Upcoming field ~ 20 publications

FSLR = First Solar; GE = GE Global Research

Conclusions on CdTe

16

• Superstrate configuration • 19.6%* efficiency on glass by GE (comparable to 20.4% of p-Si) • 16.1% module efficiency on glass by First Solar • 15.6% efficiency on glass with low temperature (<450 °C) process

13.8% efficiency on polyimide

• Substrate configuration (emerging concept) • 13.5%* efficiency on glass • 11.5%* efficiency on flexible metal foil • Similar VOC and FF as in superstrate configuration • New opportunities

* Certified efficiency


What more can be achieved?

Very low manufacturing cost and high efficiency technology

Conclusions on CIGS

17

20.4% flexible CIGS efficiency comparable to p-Si wafer cell efficiency

16% efficiency large area modules (several champions on glass and

flexible foils)

17.4%-17.8% sub-modules show prospects of >18% large area modules

CIGS production technologies are gaining maturity and next phase of

industrial plants will provide higher average efficiencies

Projection of <$0.38/Wp production cost from 1 GW factory was

announced in industrial session (3AO4.4)

Future R&D targets: 25% CIGS solar cells seem feasible

CIS with (1 eV band gap) is an excellent candidate for large area tandem

solar cells



Thin Film PV on fast track to progress Multiple advantages for enabling low cost solar electricity

High efficiency cells and modules comparable to p-Si wafer Lower module cost (€/Wp) Lower BOS cost (€/Wp) Lower cost of fully installed systems Integeration opportunities provide additional values and

functions in applications


advances in thin film pv: cigs & cdte - les pages … · advances in thin film pv: cigs &...

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