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TRANSPARENT TRANSISTORS

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					WELCOME

          1
Outline
 Introduction
 Manufacturing methods
 Types of TTFT
 Applications
 Conclusions
 Reference




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Transparent electronics is a nascent technology involving the realization of
invisible electronic circuits . Birth of transparent electronics appears to
coincide with announcement of p-type transparent electrical conductor
CuAlO2 .The availability of such p-type material, in conjunction with
conventional transparent n-type transparent electrical conductor such as
ZnO, In2O3 makes feasible construction of pn junction. The realization of
mechanically flexible, optically transparent light weight thin film
transparent transistor and circuit is essential for development of new
generation electronic devices.
Methods of manufacturing
 Spin coating
 sputtering




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Spin coating
 Deposition of the coating fluid onto the wafer or
  substrate
 Acceleration of the substrate up to its final, desired,
  rotation speed
 Spinning of the substrate at a constant rate; fluid
  viscous forces dominate the fluid thinning behavior
 Spinning of the substrate at a constant rate; solvent
  evaporation dominates the coating thinning behavior



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Sputtering
 Sputter deposition is a method of depositing thin films
  by sputtering
 Eroding, material from a "target," which then deposits
  onto a "substrate
 Sputtered atoms ejected into the gas phase are not in
  their thermodynamic equilibrium state, and tend to
  deposit on all surfaces in the vacuum chamber




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Sputtering   8
General structure




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Parameters
 Modulation r atio (Ion/Ioff ).
 Threshold voltage (Vt).
 Operating voltage.




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Types
 Metal oxide thin film transistors
 Metal oxide nano wire semiconductor transistors
 Organic semiconductor transistor




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Metal oxide TTFT
Structure




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Metal oxide semiconductor
transistor
 Operates as n channel enhancement mode device
 Channel conductivity increases with + ve gate voltage
 VGS and VDS are in the range of 0-40v
 Magnitude of operating voltage and threshold
  voltages are directly proportional to gate insulator
  thickness.
 Drain current is depends on width to length ratio
 The average optical transmission in visible region
  of electromagnetic spectrum is around 75 percent
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Forward characteristics
 Vds and Vgs   are in the range of 0 to 40V
 ID is in the range of micro ampere
 Conductivity of the channel increases with
  increases with increase in gate voltage
 Threshold voltage is around 10-20 v




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Drain current to drain voltage
characteristics
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Transfer characteristics and gate leakage current for a
                      TTFT with a
     width-to-length ratio of 10:1 for VDS=10 V




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Optical transmission spectra for
entire structure




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Optical char
 these spectra portray the raw transmission through the
  entire structure
 ZnO and ITO thickness for these device are
  100&300nm
 Average optical transmission of visible region of
  electro magnetic spectrum is 75%
 Reduction in transmission light intensity is around
  17%



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Metal oxide thin film
semiconductor transistor
 Transparent/flexible TFTs reported here are based on
  high-quality In2O3 semiconducting channel material
 doped/highly conducting In203 contacts, and a CPB
  gate dielectric on Melinex PET substrates
 The dielectric material is a cross linked polymer blend
  (CPB) film fabricated by spin-coating a mixture of
  polyvinylphenole (PVP) and a silane cross linker



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Cross section of metal oxide semi
conductor TTFT




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Optical chara of metal oxide
semiconductor TTFT




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Metal oxide nanowire
semiconductor transistor
 high performance transparent nanowire transistors
  (NWTs) individual In2O3nanowires as channels
 a multilayer self-assembled organic nano-dielec as the
  gate insulator
 NWTs use an individually addressable indium zinc
  oxide(IZO) or indium tin oxide (TO) bottom-gate
 Al as source/drain electrodes




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Metal oxide nano wire transistor




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Chara of metal oxide NWT




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Optical chara




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Organic semi conductor TTFT
 Top-contact bottom-gate transparent channel flexible
  n type OFETs were fabricated with NDI-8CN2 to
  demonstrate the unique materials properties.
 Thin NDI-8CN2 films (50 nm) were vapour-deposited
  onto acetate overhead transparency film coated with a
  spin-cast PEDOT:PSS polymeric gate
 P-UV polymer dielectric as gate insulator




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Structure of organic TTFT




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Chara of Organic TTFT




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Optical Chara of Organic TTFT




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Applications
 Wind shield display
 Solar cell
 Flat display
 LCD
 Printers
 Gas sensors




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conclusions
With the coming of transparent transistor entire
 semiconductor field undergo rapid change. Electronic
 goods will become so cheap and forming use and
 through. Since made on flexible substrate material will
 be flexible and thus causing to folded kept in pocket
 and handling become easy. The present thin film
 technology will be replaced by the transparent
 transistor thus causing better crystal display that too
 as cheep coast.


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References
 Transparent transistors new class of semiconductors makes for fast ,
    flexible, and invisible electronics By Boyd ,J,; Moore, S. K.; This paper
    appears in: Spectrum, IEEE Publication Date:2005 Volume:42,Issue:3
   ZnO-based transparent thin-film transistors-R.L. Hoffman and B J
    Norris,December 2002
   Transparent thin film transistors with Zinc iridium oxide channel
    layer;N.L.Dehull and E.S.kettenring; Journal in Applied physics
    December.
   H. Yanagi, K. Ueda, H. Ohta, M. Orita, M. Hirano, and H. Hosono,
    SolidState Commun. 121, 15 ~2001
   H. Ohta, K. Kawamura, M. Orita, M. Hirano, N. Sarukura, and H, !
    Hosono, Appl. Phys. Lett. 77, 475 ~2000


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THANK
 YOU
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DOCUMENT INFO
Description: TRANSPARENT TRANSISTORS Transparent electronics is a nascent technology involving the realization of invisible electronic circuits . Birth of transparent electronics appears to coincide with announcement of p-type transparent electrical conductor CuAlO2 .The availability of such p-type material, in conjunction with conventional transparent n-type transparent electrical conductor such as ZnO, In2O3 makes feasible construction of pn junction. The realization of mechanically flexible, optically transparent light weight thin film transparent transistor and circuit is essential for development of new generation electronic devices.