Transparent electronics is an emerging technology that employs wide band-gap semiconductors for the realization of invisible electronics circuits and optoelectronics devices.
3. INTRODUCTION
Transparent electronics is an emerging technology that
employs wide band-gap semiconductors for the realization of
invisible electronics circuits and opto-electronics devices.
In Transparent electronics, the usual opaque semiconductor
materials that are forming the basis for electronic device
fabrication are replaced with Transparent materials.
4. There are two technologies which preceded and underline
transparent electronics:
Transparent Conducting Oxides(TCOs)
Thin Film Transistors(TFTs)
MATERIALS FOR TRANSPARENT ELECTRONICS
5. Transparent Conducting Oxides
(TCO)
Transparent conducting oxides (TCOs) are
electrical conductive materials with a comparably low
absorption of light.
They are usually prepared with thin film
technologies and used in opto-electrical. devices such
as solar cells, displays, opto-electrical interfaces and
circuitries. They Possess,
1.High Optical Transparency
2.High Electrical Conductivity
The three most common TCOs are
Indium oxide (In2O3)
Tin oxide (SnO2) and
Zinc oxide (ZnO2)
Microscopic Image of TCO
coated glass substrate
6. Thin-film Transistors (TFTs)
A thin-film transistor (TFT) is a special kind of field-effect transistor made
by depositing thin films of an active semiconductor layer as well as the
dielectric layer and metallic contacts over a supporting (but non-conducting)
substrate.
7. Channel is formed from highly insulating, wide band gap
transparent semiconductor (ZnO)
Two possible configuration:
i. Bottom gate
ii. Top gate
9. Factors to Awaken Transparent Electronics
NanoMarkets believes there are four critical aspects of “transparency”
that the design and marketing of transparent electronics products needs to
focus on for it to become a serious revenue earner.
These factors include the following:
Aesthetics,
Integration
Improved economics and
Aspects of transparent materials that are not directly related to
transparency
10. Aesthetics
In order to market glass products, aesthetics have always been a key
factor.
Transparent solar panels are being used as they look better than large
framed solar panels installed in an all-too-visible fashion on a roof.
Integration
Since transparency enables visual access to multiple layers of a large-
area panel it allows an additional level of integration.
This is most obvious in the transparent overlay displays that are already
being built in prototype by the display industry.
But it also applies to smart-window concepts that are being dreamed up
that combine self-tinting windows, OLEDs and PV.
11. Improved Economics
One example of that is in the PV space
Transparent solar panels represent an example of building
integrated photovoltaics in which the cost of building materials and of the
photovoltaics can be distributed over a common substrate and total
expenditures are considerably reduced.
Non-transparent Aspects of Transparent Materials
As mentioned above, in the case of transparent conductors,
some transparent electronic materials have been developed without truly
transparent electronics in mind as an application.
However, it is possible that the reverse is also true.
That is that materials that are developed specifically with
transparent electronics in mind can find a larger market.
12. APPLICATIONS
Actual applications have been reported exploiting the transparency of
TAOSs until now.
Transparent circuits will have unprecedented applications in flat panel
displays and other electronic devices, such as see through display or novel
display structures.
Here, practical examples taking advantage of the transparency of TAOS TFTs
are: Reversible Display, ‘Front Drive’ Structure for Color Electronic Paper,
Color Microencapsulated
Electrophoretic Display, Novel Display Structure - Front Drive Structure.
Indium oxide nanowire mesh as well as indium oxide thin films were used
to detect different chemicals, including CWA simulants.
15. CONCLUSION
Great impact on human machine interaction
Lead to new applications
Transparent electronics now holds the key for many future
advancements in security, entertainment efficient utilization
of energy viz., Invisible RFIDs, UV detectors, Solar panel,
Sensors, etc.,
