5. Green nanotechnology refers to the use of
nanotechnology to enhance the environmental
sustainability of processes producing negative
externalities.
It also refers to the use of the products of
nanotechnology to enhance sustainability.
It includes making green nano-products and using
nano-products in support of sustainability.
6. GREEN NANOTECHNOLOGY HAS TWO
GOALS:
Producing nano-materials and products without
harming the environment or human health and
producing nano-products that provide solutions to
environmental problems.
Developing products that benefit the environment
either directly or indirectly.
7. For instance, nano-scale membranes can help separate
desired chemical reaction products from waste materials.
Nano-scale catalysts can make chemical reactions more
efficient and less wasteful.
Sensors at nano-scale level can form a part of process
control systems, working with nano-enabled information
systems.
Using alternative energy systems, made possible by
nanotechnology, is another way to "green" manufacturing
processes.
8. Nano-filtration
Nano-remediation
Some potential applications include:
To maintain public health, pathogens in water need to be
identified rapidly and reliably.
Water filtration may be improved with the use of nano-fiber
membranes and the use of nano-biocides, which appear
promisingly effective.
Bio-films are mats of bacteria wrapped in natural polymers.
These can be difficult to treat with antimicrobials or other
chemicals.
9. An Organic Light-Emitting Diode (OLED) is a
Light-Emitting Diode (LED) in which the
emissive electroluminescent layer is a film of
organic compound that emits light in response
to an electric current.
OLEDs are used to create digital displays in
devices such as television screens, computer
monitors, portable systems such as mobile
phones, handheld game consoles and I-pads.
12. PMOLED Display
Panel incorporated
In a smart watch.
AMOLED Display panel
incorporated in e-paper.
13. A typical OLED is composed of a layer of organic
materials situated between two electrodes, the anode
and cathode, all deposited on a substrate.
The organic molecules are electrically conductive
as a result of delocalization of pi electrons caused
by conjugation over part or all of the molecule.
These materials have conductivity levels ranging
from insulators to conductors, and are therefore
considered organic semiconductors.
14. The different manufacturing process of OLEDs lends itself
to several advantages over flat panel displays made with
LCD technology.
Lower cost in the future
Light weight and flexible plastic substrates
Wider viewing angles and improved brightness
Better power efficiency and thickness
Faster response time
15. LIFESPAN(One 2008 technical report on an OLED TV
panel found that "After 1,000 hours the blue luminance
degraded by 12%, the red by 7% and the green by 8%.)
COLOUR BALANCE(Additionally, as the OLED
material used to produce blue light degrades
significantly more rapidly than the materials that
produce other colours.)
EFFICIENCY OF BLUE OLED’S(Improvements to
the efficiency and lifetime of blue OLEDs is vital to the
success of OLEDs as replacements for LCD
technology. )
16. WATER DAMAGE(Water can instantly damage the
organic materials of the displays. Therefore, improved
sealing processes are important for practical
manufacturing).
OUTDOOR PERFORMANCE(As an emissive display
technology, OLEDs rely completely upon converting
electricity to light, unlike most LCDs which are to some
extent reflective).
POWER CONSUMPTION(While an OLED will
consume around 40% of the power of an LCD
displaying an image that is primarily black, for the
majority of images it will consume 60–80% of the
power of an LCD).
17. A solar cell, or photovoltaic cell, is an electrical
device that converts the energy of light directly into
electricity by the photovoltaic effect, which is a
physical and chemical phenomenon.
It is a form of photoelectric cell, defined as a device
whose electrical characteristics, such as current,
voltage, or resistance, vary when exposed to light.
Solar cells are the building blocks of photovoltaic
modules, otherwise known as solar panels.
18. The solar cell works in several
steps:
Irradiation of incident light
Absorption by
semiconductor materials
Exitation and de-exitation
of electrons
Current flow through
electrodes
19. The operation of a photovoltaic (PV) cell requires 3
basic attributes:
The absorption of light, generating either electron-
hole pairs or excitons.
The separation of charge carriers of opposite
types.
The separate extraction of those carriers to an
external circuit.
21. The overall efficiency is the
product of these individual
metrics.
Solar cell efficiency may be broken down into
reflectance efficiency, thermodynamic efficiency,
charge carrier separation efficiency and conductive
efficiency
22. Used As Primary Battery Power Source In Space
Applications
Water Heaters
Solar Cookers
Solar Furnaces
Solar Street Lighting
Solar Powered Sprinkler SystemToWater Public
Courtyards And Parks
23. An organic field-effect transistor is a field-effect
transistor utilizing organic molecules or polymers as
the active semiconducting layer.
A field-effect transistor (FET) is any semiconductor
material that utilizes electric field to control the shape
of a channel of one type of charge carrier, thereby
changing its conductivity.
Two major classes of FET are n-type and p-type
semiconductor, classified according to the charge type
carried.
24. Like OLEDs, OFETs can be classified into small-molecule and
polymer-based system.
Charge transport in OFETS can be quantified using a measure
called carrier mobility; currently, Rubrene-based OFETS show the
highest carrier mobility of 20–40 cm2/(v·s).
Another popular OFET material is Pentacene. Due to its low
solubility in most organic solvents, it's difficult to fabricate thin
film transistors (TFTs) from Pentacene itself using conventional
spin-cast or, dip coating methods, but this obstacle can be
overcome by using the derivative tips-Pentacene.
25. Thermally oxidized silicon is a
traditional substrate for OFETS where
the silicon dioxide serves as the gate
insulator.
The active FET layer is usually
deposited onto this substrate using
thermal evaporation ,coating from
organic solution or electrostatic
lamination.
The first two techniques result in
polycrystalline active layers; they are
much easier to produce, but result in
relatively poor transistor performance.
Numerous variations
of the solution coating
techniques are known,
including dip-coating,
spin-coating, inkjet
printing and screen
printing.
26. OFETS Are used in 7-
segment display panels
OFETS Are also widely
used in flat panel
transparent display
27. Do not require epitaxial tinplating
Low thermal budget
Simple manufacturing process
Compatible with a range of substrates
Widely used in flat panel display technology like
AMLCD(active matrix liquid crystal
display),AMOLED(active matrix organic light
emitting diode).
