History is the evidence that it is the generation of thin film revolution,that's why we're able to reduce the dimension of electronic devices.In this study,we can find some particular application of thin film coating and their limitation.

1. Present by-
MANEESH TIWAREE
under the supervision of-
DR. DEBRUNDHAR PURKYASTHA
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2.  Introduction
 Thin film solar cells
 Thin film use in solar cell
 Examples of thin film coating
 Anti reflection coating & Application
 Refrences
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3.  Thin film Optical coating –
 Antireflection purpose
 Reduces optical loses
 Filtration on solar pannel
 Self-cleaning coating(e.g. TiO2 coating)
 Refractive index gradient coating
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5. also called a Thin film Photovoltaic cell is a
second generation solar cell that is made by
depositing one or more thin layers,or thin film
of Photovoltaic material on a substrate such as
glass, plastic or metal etc.
Commercial application-CdTe, CIGS(copper
indium gallium diselanide) solar cells etc.
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6.  Small thickness required due to high absorption,
small diffusion length & high recombination
velocity
 Materials economy, very low weight per unit power
 A variety of structures available : amorphous,
polycrystalline, epitaxial
 Compatibility with solar thermal devices
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7.  One of the simplest solar cell to produce with
simple chemical conversion technique.
 Highest efficiency obtained ~10 %
 Stability of cells due to cuprous-cupric
conversion remained an issue
 Due to the emergence of higher efficiency Si
cells, this cell lost the battle of survival
 There is possibility of modification
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8. • Thick Films (Etched, EFG, melt spun /drawn) :
20% efficiency for 50 micron films
demonstrated
• Micro / Nano – Crystalline and Meso porous
Thin Films ( Vacuum Evaporated, CVD ) : 10%
efficiency for 2 micron films demonstrated
• Hybrid and tandem amorphous and
microcrystalline films/ junctions : 12 %
efficiency demonstrated
• Large Scale ( up to 50 MW) production
established
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9.  Deposition techniques include MBE, MOCVD, CVD and LPE
 Homo, Hetero, Stacked ,Multijunction, Tandem Junction and
PEC possible
 Efficiencies :Homo (23.3%), AlGaAs/Si (26.9%), AlGaAs/GaSb
 Tandem (32.6%), GaAs/InGaP (30%), Stacked InGaAs and
InGap (33%)
 Junction Formation Straightforward
 Various types of junctions possible
 Suitable for stacked cell application
 Stable Cell. Good for high temperature applications
 Expensive materials and processing
 Limited Laboratory batch size production for specialized
applications
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10.  Dielectric thin film coating
 Reduces the optical reflectivity
 Ex- spectacles, display, camera objective and
solar cells etc.
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11. 1) Single layer anti reflecting coating:
In the simplest case, an
anti-reflection thin-film coating designed for
normal incidence consists of a single quarter-
wave layer of a material the refractive index(RI)
of which is close to the geometric mean value
of the refractive indices of the two adjacent
media. In that situation, two reflections of equal
magnitude arise at the two interfaces, and these
cancel each other by destructive interference.
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d1=λ0/4η1

13.  MgF2 (RI=1.38) used on high index glasses
such as crown glass
 Fluoropolymers (RI=1.30)
 Researchers have produced films
of mesoporous silica nanoparticles with
refractive indices as low as 1.12, which
function as antireflection coatings.
 LIMITATIONS: not always possible to find suitable
material of that RI.
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14. 2) MULTI LAYER ANTI REFLECTION
COATING:
 If no suitable medium for a single-layer
coating can be found
 If anti-reflective properties are required
for a very broad wavelength range (or
for different wavelength ranges
simultaneously, or for different angles of
incidence)
 More complicated designs may be used,
which usually have to be found using
numerical techniques.
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16.  OPTICAL COMPONENT – to reduce optical
losses
 OPTICAL INTERFACES & OPTICAL FIBERS(on
the ends)
 LASER CRYSTAL
 NON LINEAR CRYSTAL
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17.  Prof.k.l.chopra(iitkh.)thinfilmlab(iitd)
 www.rpphotonics.com/anti_reflection_coating
s.
 wiki/Anti-reflective_coating
 PVEducation.org
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