polymer photovoltaic cells: prototype presentation april 15, 2010 jesus guardado, leah nation, huy...
TRANSCRIPT
Polymer Photovoltaic Cells: Prototype Presentation
April 15, 2010
JESUS GUARDADO, LEAH NATION, HUY NGUYEN, TINA RO
Understanding the Market of Solar Energy
Our Focus: Polymer Photovoltaic Cells
Easily Fabricated• Room T processing• Printable
More applications• Light weight• Flexible
Current disadvantages• Less stable• Lower efficiency
Our Design & Objective: sw-CNTs
SWCNT at 80,000x
Objective: Improve the efficiency of PVC to increase competitiveness and allow for niche application use
Carbon Nanotubes• High e- affinity• Improve carrier transport• Improves performance• Cost: $8 per m2
How It Works:
Layers are spin-coated
Cell:•Active layer•Charge acceptors•Electrodes
How It Works:
Photons => Exitons
Carbon Nanotubes:•Charge transport•Prevents recombination
How It Works:
Electron => TiO2
Hole => PEDOT
How It Works:
Electrodes accept charges
Procedure Description
Assembly• Prepare solutions and centrifuge• Spin coat substrate samples• Electrode deposition
Testing• Efficiency calculation via I-V curve• Optical absorption range of PPCs
via UV Vis spectroscopyCharacterization• Nanostructure via AFM, TEM,
SEM
Samples
Blends:–Control (0% CNT)–Sample 1 (6% CNT)– Sample 2 (3.75% CNT)
Layers (show picture):
–FTO–PEDOT–P3HT/CNTs–TiO2–Ag FTO - Fluoride Tin Oxide
PEDOT - Poly(3,4-ethylenedioxythiophene)P3HT - poly(3-hexylthiophene)
Our Design: The Cell
Our Design: The Cell
Our Design: The Cell
Our Design: The Cell
Our Design: The Cell
Modifications
Before:
• Spin coat at 2000 rpm
• 1 mg P3HT/mL chloroform
• Probe testing in dark box
• 0.0121cm2 area devices
• 10 device/slide
After: • Spin coat at 1000 rpm
• 4 mg P3HT/mL dichlorobenzene
• Probe testing in air
• 0.4cm2 area devices
• 4 devices/ slide
Considerations behind our Modifications
• FTO instead of ITO substrate availability
• 4 devices per glass slide
need precise tape placement
• P3HT solvent ->
dichlorobenzene: lower volatility
UV-Vis Results: Round II
UV-Vis Results: Round II
Testing Results: Round II
Sample 4Concentration 1
Sample 6Concentration 2
Next Steps
• 40 mg P3HT/mL dichlorobenzene• ITO patterned slides
o Pattern no tapeo ITO better light absorption range
• Spin coat P3HT layer 2xo Thicker
Less likely to short-circuit Won't trap electrons and holes
• Spin coat solvent layer before P3HT/sw-CNT layero Increase solubility
Current Progress & Future Schedule
Appendix
Renewable Energy Comparison
Cost Estimation
$/gram mg/mL L/slideslides/meter $/meter100 0.1875 0.0001 4444.44 8.33
PRODUCTION COSTS, to be added to other company's approximation of $/meter
CNT $ 15-20% cnts
Team's Resources
Expertise:• Helen Zeng; MIT Research
Laboratory of Electronics Research Scientist
• Yin-lin Xie; MIT Materials Science and Engineering Technical Instructor
• Jill Rowehl; MIT Materials Science and Engineering Doctoral Candidate
Laboratories:• Institute of Soldier Nanotechnologies
(ISN)• Organic Nanostructure Electronics
(ONE) Lab