Guided by Miss Shahida Submitted by Sajas K

Guided by Miss. Shahida Submitted by, Sajas K. K. Roll no: 18 S 5 EC

Introduction What is transparent electronics? Ø In transparent electronics the usual opaque semiconductor materials forming the basis for electronic device fabrication is replaced with transparent materials.

Ø There are two technologies which preceded and underlie transparent electronics: 1. Transparent Conducting Oxides (TCOs) 2. Thin Film Transistors (TFTs)

Transparent Conducting Oxides TCOs) Ø TCOs constitute an unusual class of materials possessing two physical properties (generally considered mutually exclusive): 1. High optical transparency. ( Eg>3. 1 e. V) 2. High electrical conductivity.

Transparent electronic devices Transparent Passive devices Transparent Active devices

Transparent Passive devices Ø Transparent Thin Film Resistors Ø Transparent Thin Film Capacitors Ø Transparent Thin Film Inductors

Transparent Thin Film Resistors

Transparent Thin Film Capacitors

Energy band in a Schottky barrier

Transparent Thin Film Transistors ØConstitutes the heart of transparent electronics ØChannel is formed from highly insulating, wide band gap transparent semiconductor(Zn. O). ØSource, drain and gate contacts are made from highly conductive TCO (ITO). ØTwo possible configurations are: a) Bottom gate b) Top gate

Possible structure, (a) Bottom gate, and (b) Top gate.

Operation of a bottom gate TFT

Strengths and Weaknesses Strengths Weaknesses Visible transparency High resistance of TCO’s Large area Lack of complementary devices Low cost (solution based deposition and printing) Low temperature processing Technological immaturity Free real estate Passive availability (R & C) Robust stable inorganic materials Safe, nontoxic materials

Applications ØActive Matrix LCD (AMLCD). ØActive Matrix Organic Light Emitting Device display backplane (AMOLED). ØValue added glass. ØTransparent electronics on opaque substrates.

ØUV detectors and arrays • Transparent solar cells • UV detectors for spectrally resolved imaging. • Security applications: Invisible cameras and Invisible RFID’s

Conclusion • Started as a mere electrical device technology during world war 2, transparent electronics now holds the key for many future advancements in security, entertainment efficient utilization of energy.

Reference • ‘Transparent Electronics ’, Springer publications, J. F. Wager, D. A. Keszler, R. E. Presley. • ‘Transparent electronics: from synthesis to applications’, Wiley publications: Antonio Facchetti, Tobin J. Marks

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