1 PV prospects: thin-film cells - UBCcourses.ece.ubc.ca/577/priv/8.PV_Prospects.pdf ·...
Transcript of 1 PV prospects: thin-film cells - UBCcourses.ece.ubc.ca/577/priv/8.PV_Prospects.pdf ·...
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PV prospects: thinPV prospects: thin--film cellsfilm cells
LECTURE 8
• Si cell costs
• optimizing conversion efficiency
• thin-film cells
• Schottky-barrier theory
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Silicon materialSilicon material
X
XXX
X
Metallurgical grade Si
Semiconductor grade Si Si + 3HCl SiHCl3 + H2
3SingleSingle--crystal Si modulescrystal Si modules
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Thin scThin sc--Si solar cellsSi solar cells
10X reduction in Si use claimedK.J. Weber et al., IEEE Photovoltaic Specialists Conf., 991-994, 2005.
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mcmc--Si solar cellsSi solar cells
“The lowest retail price for a multi-crystalline silicon solar module is $1.74 per watt (€1.29 per watt) from a US retailer.”
http://www.udel.edu/igert/pvcdrom/index.html
http://www.solarbuzz.com/Moduleprices.htm
6Cost of PV modulesCost of PV modules
The lowest retail price for a multicrystalline silicon solar module is $1.61 per watt (€1.13 per watt) from a US retailer. The lowest retail price for a monocrystallinesilicon module is $1.48 per watt (€1.04 per watt), from an Asian retailer. Brand, technical attributes, and certifications do matter. The lowest thin film module price is at $1.40 per watt (€0.98 per watt) from a US-based retailer.
http://www.solarbuzz.com/Moduleprices.htm
7Alternatives to limitedAlternatives to limited--area Si: thinarea Si: thin--film cellsfilm cells
Requirements:
• near optimum bandgap
• direct bandgap
• long minority carrier lifetime
• abundant material
• large-area-deposition capability
8Efficiency and Efficiency and bandgapbandgap
CIGSCdTe
Why is there a maximum in the relationship?
UMTD [Sec. 7.5.1]
9Optimum Optimum bandgapbandgap
10SolarSolar--cell efficienciescell efficiencies
Sarah Kurtz NREL/PR-520-46924
11CIGS and CIGS and CdTeCdTe: thin: thin--film contendersfilm contenders
Noufi and Zweibel, IEEE 4th World conf on PEC, 317-320, 2006
12Commercial Commercial CdTeCdTe: First Solar: First Solar
“Before First Solar's manufacturing innovations, cadmium-telluride photovoltaic cells were the size of postage stamps; now the company makes them as big as window panes.”
http://spectrum.ieee.org/energy/renewables/first-solar-quest-for-the-1-watt
13Towards commercial CIGS: Towards commercial CIGS: NanosolarNanosolar
NREL Certifies 15.3% Nanosolar Foil Efficiency
By Nanosolar Communications - September 9, 2009
http://www.nanosolar.com/technology
14Examination of CIGS cellsExamination of CIGS cells
• Vacancy doping of CIGS
• The role of the CdS film
• The role of the ZnO/ITO layers
• Replacement of CdS/ZnO/ITO with a Schottky barrier
Noufi and Zweibel, IEEE 4th World conf on PEC, 317-320, 2006
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no grading
graded composition of Ga near front.