This document discusses thin film applications such as solar cells, thin film transistors, optical coatings, and thin film batteries. It provides details on how each of these applications uses thin films, including how solar cells convert light to electricity using electron-hole pairs, how thin film transistors act as switches in LCD displays, and how optical coatings can reduce reflections. Thin film batteries are also summarized as being solid-state and potentially flexible. In general, the document outlines the key uses and operating principles of several important thin film technologies.

1. APPLICATION OF THIN FILMS
ANEETTA DAVIS
MSc NS & T, 2nd SEM
MOUNT CARMEL COLLEGE
GUIDED BY: PRADEEP SIR

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.

3. APPLICATIONS
• SOLAR CELLS
• THIN FILM TRANSISTORS
• OPTICAL COATING
• THIN FILM BATTERIES

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.

5. There are several conditions that a thin film
solar cell must satisfy in order to exhibit
efficient photovoltaic energy conversion:
• The optical absorption coefficient (α) must be
large enough
• The photogenerated electrons and holes must
be collected efficiently by contacting
electrodes on the both sides of the active film
material

7. 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.

8. 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.

9. 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.

10. ADVANTAGES
• Light weight
• Portable
• Low power
consumption
• High resolution
• Wide variety of
commercial application

11. 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.

12. 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.

13. 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.

14. Antireflection coating

15. 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.
• Potential applications include:
Pacemakers
Neural stimulators
Drug delivery system

17. OTHER APPLICATIONS
• Semiconductors
• Super capacitors
• Data storage
• Photo electrochemical cells
• Drug delivery
• Nanomedicine

18. REFERENCES
• http://www.worldscientific.com/doi/pdf/10.1
142/S2010194513010696
• http://shodhganga.inflibnet.ac.in/bitstream/1
0603/4025/8/08_chapter%202.pdf

19. THANK YOU