Introduction

What is transparent electronics?

In transparent electronics the usual opaque

semiconductor materials forming the basis for

electronic device fabrication is replaced with

transparent materials.

There are two technologies which preceded

and underlie transparent electronics:

1. Transparent Conducting Oxides (TCOs)

2. Thin Film Transistors (TFTs)

Transparent Conducting Oxides TCOs)

TCOs constitute an unusual class of materials

possessing two physical properties (generally

considered mutually exclusive):

1. High optical transparency. ( Eg>3.1eV)

2. High electrical conductivity.

Transparent electronic devices

Transparent Passive devices

Transparent Active devices

Transparent Passive devices

Transparent Thin Film Resistors

Transparent Thin Film Capacitors

Transparent Thin Film Inductors

Transparent Thin Film Resistors

Transparent Thin Film Capacitors

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Energy band in a Schottky barrier

Transparent Thin Film Transistors

Constitutes the heart of transparent

electronics

Channel is formed from highly insulating, wide

band gap transparent semiconductor(ZnO).

Source, drain and gate contacts are made

from highly conductive TCO (ITO).

Two 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

Active Matrix LCD (AMLCD).

Active Matrix Organic Light Emitting Device

display backplane (AMOLED).

Value added glass.

Transparent electronics on opaque substrates.

UV 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.