2. WHY POLYFLUORENE?
Polyfluorenes are a class of polymeric materials. They are of interest because
similar to other conjugated polymers, they are currently being used in light-emitting
diodes, field-effect transistors, and plastic solar cells.
The synthesis of monomers based on alkylated fluorene which can be then
copolymerized with other monomers to form conjugated copolymers whose band
gap is tuned by the regular insertion of the an electron-donating or electron-
withdrawing units, (3,4-ethylenedioxy)thiophene and pyridine, respectively.
3. WHAT IS FLUORENE?
Fluorene, a principal repeat unit in polyfluorene derivatives, was
isolated from coal tar and discovered by Marcellin Berthelot prior
to 1883. Its name originates from its
interesting fluorescence. Fluorene became the subject of
chemical-structure related color variation (visible rather than
luminescent).
5. POLYFLUORENE DERIVATIVES USED IN…..
These are commonly and extensively used in the fabrication of
devices such as Plastic Solar cells and Organic Light Emitting
Diodes (OLED’s) mainly.
In OLEDs, polyfluorenes are desirable because they are the only
family of conjugated polymers that can emit colors spanning the
entire visible range with high efficiency and low operating voltage.
6. ORGANIC SOLAR CELLS
An organic solar cell or plastic solar cell is a type of polymer
solar cell that uses organic electronics, a branch of electronics
that deals with conductive organic polymers or small organic
molecules, for light absorption and charge transport to
produce electricity from sunlight by the photovoltaic effect.
7. WHY PLASTIC SOLAR CELLS…
The plastic used in organic solar cells has low production costs in
high volumes. Combined with the flexibility of organic molecules,
organic solar cells are potentially cost-effective for photovoltaic
applications.
Molecular engineering (e.g. changing the length and functional
group of polymers) can change the energy gap, which allows
chemical change in these materials. The optical absorption
coefficient of organic molecules is high, so a large amount of light
can be absorbed with a small amount of materials.
8. CLEAN ENERGY SUPPLY NEEDED FOR QUALITY OF LIFE
Fossil and nuclear fuels are costly.
If we include the environmental cost.
The sun shines on everyone.
Ideal for distributed power generation and remote location.
Tap solar energy directly
Ideal for distributed power generation
More environmental friendly
10. AREA OF SOLAR CELL NEEDED…..
With 10% efficient solar cell area of solar cell needed in 2004
India 60 km × 60 km (0.12% area)
World need: 350 km × 350 km
11. ANNUAL VARIATION OF SOLAR
INSOLATION
The energy (or insolation) received on a surface throughout the year
varies relatively little from year to year.
12. HISTORY
1839 Photovoltaic effect discovered by Edmond Becquerel
1954 First Silicon Solar Cell inBell Lab by Chapin, Fuller and Pearson (η∼6%)
1970s Surge in research to harness solar energy
1986 Heterojunction Organic Solar Cell by Tang of Eastman Kodak
2007 Highest efficiency solar cells with η ηη η~40.7% in Spectrolab
A big surge in solar cells research & development is underway
15. SOLAR ENERGY USAGE AND PRICING
Solar Energy: 30 c (Rs. 12) per kWh
Need to lower cost to 10c (Rs.4) per kWh and below
Solar markets
(average of last 5
years)
Solar
Price/Competing
Energy source
Remote Industrial 17% 0.1-0.5 times
Remote habitation 22% 0.2-0.8 times
Grid Connected 59% 2-5 times
Consumer Indoor 2% n/a
16. ELECTRICITY GENERATION COST
Energy Source Cost
Combined cycle gas turbine 3 ¢ -5 ¢ (Rs.1.20-Rs.2.00)
Wind 4 ¢ -7 ¢ (Rs.1.60-Rs.2.80)
Biomass gasification 7 ¢ -9 ¢ (Rs.2.80-Rs.3.60)
Remote diesel generation 20 ¢ -40 ¢ (Rs.8.00-Rs.16.00)
Solar PV central station 20 ¢ -30 ¢ (Rs.8.00-Rs.12.00)
Solar PV Distributed 20 ¢ -50 ¢ (Rs.8.00-Rs.20.00)
18. LOWERING COST OF SOLAR CELLS
Thin Film Solar Cells
■ Multiple junction solar cells (a-Si:H, a-SiGe:H)
■ CdTe based cells (CdTe, CdS)
■ CuInSe2 (CIS) Ternary & Multinary compound solar cells
■ Multicrystalline/Microcrystalline silicon solar cells
■ Thin film GaAs solar cells
■ Organic solar cells
24. WHAT IS AN OLED ?
OLED - Organic Light Emitting Diode
An OLED is a light emitting diode (LED) which emissive
electroluminescent layer is composed of a film of organic
compounds
25. HISTORY
• First developed in the early 1950s in France.
• 1960s-AC-driven electroluminescent cells using doped anthracene was developed.
• In 1987 Chin Tang and Van Slyke introduced the first light emitting diodes from thin
organic layers.
• In1990 electroluminescence in polymers was discovered.
27. TYPES OF OLED
Passive OLEDs
• The organic layer is between cathode
& anode run perpendicular.
• The intersections
form the pixels.
• Easy to make.
• Use more power.
• Best for small screens.
28. Active OLEDs
• Full layers of cathode and
anode.
• Anode over lays a thin film
transistor (TFT).
• Requires less power.
• Higher refresh rates.
• Suitable for large screens
29. APPLICATIONS OF
OLED
• Televisions
• SONY
• LG transparent TV
• Cell Phone screens
• Wrist Watch
• Computer Screens
• Laptops
• Desktops
• Bendable Devices
• Portable Device displays
• Philips Go Gear MP3 Player
30. ADVANTAGES
• Faster response time than LCDs
• Consume significantly less energy
• Can be transparent when off
• Flexible and Conformal Displays
• Thinner display-No backlight required
• Better contrast ratio
• Safer for the environment
• Wider viewing angles; up to 170 degrees
• OLEDs refresh almost 1,000 times faster
then LCDs
• Low cost materials and fabrication method
• Less Expensive than LCD due to lesser
components
• Can be made using plastic screens; LCDs
require glass backing
31. FUTURE USES FOR OLED
Data glass
GPS system
OLED – in future cars
Curved OLED displays, placed on non-flat
surfaces
And many more we cannot even imagine today
Scroll Laptop
• Nokia concept OLED Laptop
32. DEFINITIONS
Electroluminescence (EL) is an optical
phenomenon and electrical phenomenon in which a
material emits light in response to an electric
current passed through it, or to a strong electric field
A pixel (or picture element) is the smallest item of
information in an image
A thin-film transistor (TFT) is a special kind of field-effect
transistor made by depositing thin films of a semiconductor active
layer.
The refresh rate is the number of times in a second that display
hardware draws the data it is being given
36. SONY PSP2 CONCEPT
Oled rollable display.
A flexible OLED display that
can be rolled around the main
electronics core but, when
charged, automatically stiffens
with minimal bezel surround.
37. BENDABLE OLED DISPLAY
Organic Light Emitting Diode (OLED) technology is
threatening the Liquid Crystal Display, or LCD, standard
because of its flexibility, low power consumption and
versatility.
39. MY EXPERIMENTAL WORK
I reported the synthesis and characterization of two monomers
based on alkylated fluorene namely 2,7-Dibromo-9,9-
didecylfluorene and 2,7-Bis[4,4,5,5-tetramethyl-(1,3,2)-
dioxaborolan-2-yl]-9,9didecylfluorene which can then
copolymerized with other monomers to form conjugated
copolymers. The monomers synthesized are neither polymerized
nor tested for the applications due to some limitations in doing,
but copolymers of similar compounds such as 2,7-Dibromo-9,9-
dioctylfluorene and 2,7-Bis[4,4,5,5-tetramethyl-(1,3,2)-
dioxaborolan-2-yl]-9,9dioctylfluorene have optical properties
such that they are suitable materials for device developments
such as electrochromics, PLEDs, and solar cells
42. RESULTS
First two steps of the method 1 are successful but unfortunately
the final step i.e synthesis of 2,7-Bis[4,4,5,5-tetramethyl-(1,3,2)-
dioxaborolan-2-yl]-9,9didecylfluorene is not achieved.
Then by following Method 2 we are able to synthesize both the
monomers.
Due to some limitations in techniques as well as time to
synthesize and characterize the polymers which can be prepared
using these monomers is not performed.
43. CONCLUSION
As Solar cells and OLED technology is vastly growing now-a-
days I aimed to synthesize few molecules which can be used in
the fabrication of Solar cell and OLED devices.
44. REFERENCES
All images are taken from Google Images.
Solar Cells data is from www.solarbuzz.com.
