Powered Paint: Nanotech Solar Ink
Powered Paint: Nanotech Solar Ink Brian A. Korgel http://www.che.utexas.edu/korgel-group/ http://www.che.utexas.edu/ngpv/ Department of Chemical Engineering, Texas Materials Institute, Center for Nano- and Molecular Science and Technology The University of Texas at Austin [email protected]
GOAL: Make photovoltaic (PV) electricity a major source of energy
The main problem with photovoltaics for large-scale energy generation is cost
Current cost $2-4/W installed Needed Cost $1/W installed
Ways to Use Power from the Sun • Feed electricity to the grid…large-scale solar farms (largest current market for PVs)
• Off-grid stationary power, i.e., rooftop panels, architectural (still a developing market…the technology is not sufficient)
• Portable power on-demand (not yet a market…need the technology)
Photovoltaic Power Con’s • PV electricity is expensive Convert sunlight compared to conventional directly to electricity energy sources (like coal and natural gas) Sunlight (solar energy) is “free” • “Off-grid” power solutions are very expensive, Sunlight is plentiful cumbersome The technology exists • Portable, light-weight, efficient, low-cost If the technology were photovoltaics are in their better, electricity could be generated from infancy
Pro’s
•
• • • •
almost anywhere
Silicon dominates the solar cell market It’s relatively expensive and mature Cost is artificially low because of government subsidy
Manufacturing capacity is now higher than demand
Alternatives to Si…
Multijunction III-V solar cells Amorphous silicon CdTe CIGS (Cu(In,Ga)Se2)
Commercially successful
Commercially available
Organic semiconductors Dye-sensitized solar cells Nanocrystal inks
Extremely high efficiency but extremely expensive (only used for aerospace applications)
Commercially available
Under development
Change our mindset…change the way solar cells are made
Why do this now?...New (nano)materials exist that did not 5-10 years ago
Semiconductor fabric Printable inorganic semiconductors
Organic materials-based solar cells (new materials since 1980’s)
Konarka
Roll-to-roll processing of polymer-based solar cells (Mekoprint A/S)
Organic materials generally are not very stable under sunlight for long periods of time…is there a way to combine processing of organics with high performance and stability of inorganics?
Can we make a “solar” paint (inorganic) that can convert sunlight energy into electricity? Solar paint?
100 nm
A Photovoltaic Device How it works:
e-
Photons (Light)
h+
Light absorption creates an electron and hole
A Photovoltaic Device How it works:
e-
Photons (Light)
h+
The electron and hole are separated… requires layers of materials This is the basic design of every solar cell
Concept: process the semiconductor layer by room temperature ink deposition
Metal n-type semiconductor Nanocrystal ink Metal Glass or plastic support
First, we need an ink:
Copper indium galllium selenide: CIGS
First, we need an ink: Develop a chemical synthesis of CIGS nanocrystals
First, we need an ink: N2 TC
CuCl + InCl3 + 2Se
Develop a chemical synthesis of CIGS nanocrystals
oleylamine, 240oC
CuInSe2 nanocrystals
15 – 20 nm diameter CuInSe2 nanocrystals
16
Nanocrystal PV Device Fabrication 1. Deposit metal foil onto a flexible substrate
2. Solution-deposit nanocrystals
4. Pattern metal collection grid
3. Deposit heterojunction partner layers (CdS/ZnO)
Nanocrystal Film Formation For the solar cell, need uniform films of nanocrystals.
• Standard
ZnO
CdS
CuInSe2 nanocrystals Mo Glass
Cell
Efficiency Voc
0.341% 329 mV
Jsc Fill Factor
3.26 mA/cm2 0.318
Nanocrystal Film Formation For the solar cell, need uniform films of nanocrystals.
CIS Nanocrystal PVPCE=3.063% device NP706 s1-p3; Current Density (mA/cm2)
160 140 120 100
Jsc: -16.287 mA/cm2 Voc: 0.412 V FF: 0.456 PCE: 3.063 %
80 60
Efficiency of 3.1%
40 20 0 DARK
-20 -40 -1.5
LIGHT
-1
-0.5
0
0.5
1
1.5
Voltage (V)
V. A. Akhavan, M. G. Panthani, B. W. Goodfellow, D. K. Reid, B. A. Korgel, “Thickness-limited performance of CuInSe2 nanocrystal photovoltaic devices,” Optics Express, 18 (2010) A411-A420.
Efficiency of 2% on plastic
The challenge is to demonstrate commercially viable efficiencies of >10% (currently, the devices function at 3%)
Korgel group milestone chart for CIGS Nanocrystal PVs
3.1%
Project conception (Sept., 2006)
Sprayed CIGS nanocrystal device 6.48% efficiency
March, 2012
New concepts enabled by nanotechnology Low-cost solar cells that can be printed like newspaper and Nanomaterials for bullet-proof vests that can charge your ipod
From the Oxford English Dictionary:
nanowire n. wire, or a wire, that has a thickness or diameter of a few nanometres.
Human Hair Si nanowire
Nanowire FET
Ge nanowire
Paper made of SFLSgrown Si nanowires
10 mm
Silicon nanowire fabric has an extremely high optical density… much less material is needed to absorb the light
CuInSe2 Nanowire Fabric
Proof of concept: CIS Nanowire Photovoltaic
Concept: Photovoltaic Fabric/Textiles • Avoid embedding obtrusive, bulky, heavy solar cells into fabric. • Create semiconductor fabric that is mechanically flexible, lightweight, absorbs sunlight and can be engineered to generate a photovoltaic effect.
Next Generation Thin Film Devices: need high efficiency to get to $1/W
Vision: Enable next generation thin film PVs with >30% efficiency Industry/University Cooperative Research Center on Next Generation Photovoltaics http://www.che.utexas.edu/ngpv/
Change our mindset…change the way solar cells are made
Why do this now?...New (nano)materials exist that did not 5-10 years ago
Semiconductor fabric Printable inorganic semiconductors
Special Acknowledgement to:
1st gen PV students
Vahid Akhavan
Brian Goodfellow
Matt Panthani
Key undergraduate researchers
Danny Hellebusch
Dariya Reid
Next gen PV students Funding from Robert A. Welch Foundation; Air Force Research Laboratory; National Science Foundation
Chet Steinhagen
Jackson Stolle
Taylor Harvey
GOAL: Make photovoltaic (PV) electricity a major source of energy
The main problem with photovoltaics for large-scale energy generation is cost
Current cost $2-4/W installed Needed Cost $1/W installed
Ways to Use Power from the Sun • Feed electricity to the grid…large-scale solar farms (largest current market for PVs)
• Off-grid stationary power, i.e., rooftop panels, architectural (still a developing market…the technology is not sufficient)
• Portable power on-demand (not yet a market…need the technology)
Photovoltaic Power Con’s • PV electricity is expensive Convert sunlight compared to conventional directly to electricity energy sources (like coal and natural gas) Sunlight (solar energy) is “free” • “Off-grid” power solutions are very expensive, Sunlight is plentiful cumbersome The technology exists • Portable, light-weight, efficient, low-cost If the technology were photovoltaics are in their better, electricity could be generated from infancy
Pro’s
•
• • • •
almost anywhere
Silicon dominates the solar cell market It’s relatively expensive and mature Cost is artificially low because of government subsidy
Manufacturing capacity is now higher than demand
Alternatives to Si…
Multijunction III-V solar cells Amorphous silicon CdTe CIGS (Cu(In,Ga)Se2)
Commercially successful
Commercially available
Organic semiconductors Dye-sensitized solar cells Nanocrystal inks
Extremely high efficiency but extremely expensive (only used for aerospace applications)
Commercially available
Under development
Change our mindset…change the way solar cells are made
Why do this now?...New (nano)materials exist that did not 5-10 years ago
Semiconductor fabric Printable inorganic semiconductors
Organic materials-based solar cells (new materials since 1980’s)
Konarka
Roll-to-roll processing of polymer-based solar cells (Mekoprint A/S)
Organic materials generally are not very stable under sunlight for long periods of time…is there a way to combine processing of organics with high performance and stability of inorganics?
Can we make a “solar” paint (inorganic) that can convert sunlight energy into electricity? Solar paint?
100 nm
A Photovoltaic Device How it works:
e-
Photons (Light)
h+
Light absorption creates an electron and hole
A Photovoltaic Device How it works:
e-
Photons (Light)
h+
The electron and hole are separated… requires layers of materials This is the basic design of every solar cell
Concept: process the semiconductor layer by room temperature ink deposition
Metal n-type semiconductor Nanocrystal ink Metal Glass or plastic support
First, we need an ink:
Copper indium galllium selenide: CIGS
First, we need an ink: Develop a chemical synthesis of CIGS nanocrystals
First, we need an ink: N2 TC
CuCl + InCl3 + 2Se
Develop a chemical synthesis of CIGS nanocrystals
oleylamine, 240oC
CuInSe2 nanocrystals
15 – 20 nm diameter CuInSe2 nanocrystals
16
Nanocrystal PV Device Fabrication 1. Deposit metal foil onto a flexible substrate
2. Solution-deposit nanocrystals
4. Pattern metal collection grid
3. Deposit heterojunction partner layers (CdS/ZnO)
Nanocrystal Film Formation For the solar cell, need uniform films of nanocrystals.
• Standard
ZnO
CdS
CuInSe2 nanocrystals Mo Glass
Cell
Efficiency Voc
0.341% 329 mV
Jsc Fill Factor
3.26 mA/cm2 0.318
Nanocrystal Film Formation For the solar cell, need uniform films of nanocrystals.
CIS Nanocrystal PVPCE=3.063% device NP706 s1-p3; Current Density (mA/cm2)
160 140 120 100
Jsc: -16.287 mA/cm2 Voc: 0.412 V FF: 0.456 PCE: 3.063 %
80 60
Efficiency of 3.1%
40 20 0 DARK
-20 -40 -1.5
LIGHT
-1
-0.5
0
0.5
1
1.5
Voltage (V)
V. A. Akhavan, M. G. Panthani, B. W. Goodfellow, D. K. Reid, B. A. Korgel, “Thickness-limited performance of CuInSe2 nanocrystal photovoltaic devices,” Optics Express, 18 (2010) A411-A420.
Efficiency of 2% on plastic
The challenge is to demonstrate commercially viable efficiencies of >10% (currently, the devices function at 3%)
Korgel group milestone chart for CIGS Nanocrystal PVs
3.1%
Project conception (Sept., 2006)
Sprayed CIGS nanocrystal device 6.48% efficiency
March, 2012
New concepts enabled by nanotechnology Low-cost solar cells that can be printed like newspaper and Nanomaterials for bullet-proof vests that can charge your ipod
From the Oxford English Dictionary:
nanowire n. wire, or a wire, that has a thickness or diameter of a few nanometres.
Human Hair Si nanowire
Nanowire FET
Ge nanowire
Paper made of SFLSgrown Si nanowires
10 mm
Silicon nanowire fabric has an extremely high optical density… much less material is needed to absorb the light
CuInSe2 Nanowire Fabric
Proof of concept: CIS Nanowire Photovoltaic
Concept: Photovoltaic Fabric/Textiles • Avoid embedding obtrusive, bulky, heavy solar cells into fabric. • Create semiconductor fabric that is mechanically flexible, lightweight, absorbs sunlight and can be engineered to generate a photovoltaic effect.
Next Generation Thin Film Devices: need high efficiency to get to $1/W
Vision: Enable next generation thin film PVs with >30% efficiency Industry/University Cooperative Research Center on Next Generation Photovoltaics http://www.che.utexas.edu/ngpv/
Change our mindset…change the way solar cells are made
Why do this now?...New (nano)materials exist that did not 5-10 years ago
Semiconductor fabric Printable inorganic semiconductors
Special Acknowledgement to:
1st gen PV students
Vahid Akhavan
Brian Goodfellow
Matt Panthani
Key undergraduate researchers
Danny Hellebusch
Dariya Reid
Next gen PV students Funding from Robert A. Welch Foundation; Air Force Research Laboratory; National Science Foundation
Chet Steinhagen
Jackson Stolle
Taylor Harvey
