TRANSPARENT ELECTRONICS

Submitted by-REHAN FAZAL1171110180

Electronics and Instrumentation

INRODUCTION

Researchers at Oregon State University have reported their first example of an entirely new class of materials which could be used to make transparent transistors that are inexpensive, stable, and eco-friendly. This could lead to new industries and a broad range of new consumer products, The possibilities include electronic devices produced so cheaply they could almost be one-time "throw away" products, better large-area electronics such as flat panel screens, or flexible electronics that could be folded up for ease of transport. Findings about this new class of "thin-film" materials are called amorphous heavy-metal cation multicomponent oxides.

What is transparent electronics?

Invisible Electronics In transparent electronics , the usual

opaque semiconductor materials forming the basis for electronic device fabrication is replaced with transparent materials.

Transparent electronics is an emerging technology that employs wide band-gap semiconductors for the realization of invisible circuits

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. ( E.g.>3.1eV)

2. High electrical conductivity.

Transparent electronic devices

Transparent Passive devices

Transparent Active devices

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 gateb) Top gate

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

Thin film resistors and capacitors

Advances made in Transparent Electronics

Significant advances in the emerging science of transparent electronics, creating transparent "p-type" semiconductors that have more than 200 times the conductivity of the best materials available for that purpose a few years ago. This basic research is opening the door to new types of electronic circuits that, when deposited onto glass, are literally invisible. These "p-type" materials will be necessary for the diodes and transistors that are essential to more complex electronic devices. Only a few laboratories in the world are working in this area, mostly in Japan, the OSU scientists. As recently as 1997, the best transparent p-type transparent conductive materials could only conduct one Siemen/cm, which is a measure of electrical conductivity. The most sophisticated materials recently developed at OSU now conduct 220 Siemen/cm.

Strengths WeaknessesVisible 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  

STRENGTHS AND WEAKNESSES

APPLICATION

                                                                                       They have been widely used in a variety of applications like:

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.

THANK YOU