1. APPLICATION OF THIN FILMS
ANEETTA DAVIS
MSc NS & T, 2nd SEM
MOUNT CARMEL COLLEGE
2. WHAT IS THIN FILM?
• thin = less than about one micron ( 10,000 Angstroms,
1000 nm)
• film = layer of material on a substrate
The need for thin films is because we can alter their
properties and for miniature devices.
4. SOLAR CELLS
• This is a cheaper raw material than crystalline silicon. No
structural damage!
• The conversion of solar light to electric power is one of the
available renewable sources of energies.
• The basic physical principle involved is the absorption of
photon resulting in the creation of electron-hole pairs; the
excess electrons in the conduction band, and holes in the
valence band.
• Depositing one or several thin layers of photovoltaic material
onto a substrate is the basic gist of how thin-film solar cells
are manufactured.
5. ADVANTAGES OF THIN FILM SOLAR CELLS
• Mass-production is simple and potentially cheaper to
manufacture than crystalline-based solar cells.
• Can be made flexible, which opens up many new potential
applications.
• High temperatures and shading have less impact on solar
panel performance.
• In situations where space is not an issue, thin-film solar panels
can make sense.
6. DISADVANTAGES OF THIN FILM SOLAR
CELLS
• Thin-film solar panels are in general not very useful for in
most residential situations. They are cheap, but they also
require a lot of space.
• Thin-film solar panels tend to degrade faster than mono- and
polycrystalline solar panels, which is why they typically come
with a shorter warranty
8. THIN FILM TRANSISTORS
• TFT is made by
depositing thin films on
semiconductor.
• A common substrate is
glass since the primary
application of TFT’s are
Liquid Crystal Displays.
9. What is TFT LCD ?
• TFT LCD is a sandwich
like structure with
crystal filled between
two glass plates.
• It is common in
notebook computers ,
that it has transistor for
each pixel.
10. How do they work ?
• TFT glass has as many TFTs as the number of pixels
displayed.
• Millions of pixels create an image on the display.
• TFT’s act as switches to individually turn ‘on’ and ‘off’ for
each pixel
• A color filter glass has color filter which generates color.
• Diffuser distributing the light evenly near the viewing area.
• Liquid Glass Crystals move according to the change in
voltage between the TFT glass and color filter.
11. ADVANTAGES
• Light weight
• Portable
• Low power
consumption
• High resolution
• Wide variety of
commercial application
12. DISADVANTGES
• The general comment
from the people is that
the LCD TFT gets
switched off after
sometime .
• The liquid crystals inside
the display are
poisonous
• Spills off from a cracked
display should be
washed with soap water.
13. OPTICAL COATING
An optical coating is one or more thin layers of
material deposited on an optical component
such as a lens or mirror, which alters the way
in which the optic reflects and transmits light.
14. ANTIREFELCTION COATING
• Whenever light travels between two interfaces of
different refractive index, some of the light is
reflected.
• These reflections form flare images.
• The coating of optical surfaces with antireflection
coatings has resolved this problem.
• The antireflection coatings should be applied to
optical surfaces containing germanium, silicon or
materials with high refractive index.
16. THIN FILM BATTERIES
• Unlike typical batteries, thin film batteries are
all solid-state.
• In many cases they can be made flexible.
• They can be manufactured using normal thin
film deposition techniques.
17. HOW DO THEY WORK?
Thin film lithium ion batteries are widely used in the industry. It
consists of:
• Cathode materials: Cathode materials in thin film lithium ion
batteries are the same of what is seen in classical lithium ion
batteries. They are normally metal oxides that are deposited
as a film by various methods like pulsed laser deposition,
magnetron sputtering, CVD, Sol-gel processing.
• Electrolyte: The greatest difference between classical lithium
ion batteries and thin, flexible, lithium ion batteries is in
the electrolyte material used. The electrolyte plays a major
role in safe battery operation. LiPON, lithium phosphorus
oxynitride, is an amorphous glassy material used as an
electrolyte material in thin film flexible batteries. Layers of
LiPON are deposited over the cathode material at ambient
temperatures by RF magnetron sputtering. This forms
the solid electrolyte used for ion conduction between anode
and cathode.
18. •SEPARATOR MATERIAL: Here the electrolyte is a solid, which
conveniently satisfies both the ion transportation and the physical
separation requirements without the need for a dedicated
separator.
•CURRENT COLLECTOR: Current collectors in thin film batteries
must be flexible, have high surface area, and be cost-effective.
