Topics for “ SAVITECH ” in AAGAAZ

There are five topics in “ SAVITECH ” ,from this you have to submit your synopsis maximum of 4 pages and then after you have to prepare your .ppt presentation and it will be of 10 mins.

The topics are as follows :-

(1). 4G - Technology.
(2). DOHC (Dual overhead camshaft).
(3). Nanobots.
(4). Criptography.
(5). Solid waste management.


There is a sample of synopsis is given on "LIGHT EMITTING POLYMER".

Introduction:
The seminar is about polymers that can emit light when a voltage is applied to it. The structure comprises of a thin film of semiconducting polymer sandwiched between two electrodes (cathode and anode).When electrons and holes are injected from the electrodes, the recombination of these charge carriers takes place, which leads to emission of light .The band gap, ie. The energy difference between valence band and conduction band determines the wavelength (colour) of the emitted light.
They are usually made by ink jet printing process. In this method red green and blue polymer solutions are jetted into well defined areas on the substrate. This is because, PLEDs are soluble in common organic solvents like toluene and xylene .The film thickness uniformity is obtained by multi-passing (slow) is by heads with drive per nozzle technology .The pixels are controlled by using active or passive matrix.
The advantages include low cost, small size, no viewing angle restrictions, low power requirement, biodegradability etc. They are poised to replace LCDs used in laptops and CRTs used in desktop computers today.
Their future applications include flexible displays which can be folded, wearable displays with interactive features, camouflage etc.

What is LEP?

It is a polymer that emits light when a voltage is applied to it. The structure comprises a thin-film of semiconducting polymer sandwiched between two electrodes (anode and cathode) as shown in fig.1. When electrons and holes are injected from the electrodes, the recombination of these charge carriers takes place, which leads to emission of light that escapes through glass substrate. The bandgap, i.e. energy difference between valence band and conduction band of the semiconducting polymer determines the wavelength (colour) of the emitted light.


Construction :

Light-emitting devices consist of active/emitting layers sandwiched between a cathode and an anode. Indium-tin oxides typically used for the anode and aluminum or calcium for the cathode. Fig.2.1(a) shows the structure of a simple single layer device with electrodes and an active layer.
Single-layer devices typically work only under a forward DC bias. Fig.2.1(b) shows a symmetrically configured alternating current light-emitting (SCALE) device that works under AC as well as forward and reverse DC bias.
In order to manufacture the polymer, a spin-coating machine is used that has a plate spinning at the speed of a few thousand rotations per minute. The robot pours the plastic over the rotating plate, which, in turn, evenly spreads the polymer on the plate. This results in an extremely fine layer of the polymer having a thickness of 100 nanometers. Once the polymer is evenly spread, it is baked in an oven to evaporate any remnant liquid. The same technology is used to coat the CDs.

Advantages and Disadvantages :

Advantages:-
• Require only 3.3 volts and have lifetime of more than 30,000 hours.
• Low power consumption.
• Self luminous.
• No viewing angle dependence.
• Display fast moving images with optimum clarity.
• Cost much less to manufacture and to run than CRTs because the active material is plastic.
• Can be scaled to any dimension.
• Fast switching speeds that are typical of LEDs.
• No environmental draw backs.
• No power in take when switched off.
• All colours of the visible spectrum are possible by appropriate choose of polymers.
• Simple to use technology than conventional solid state LEDs and lasers.
• Very slim flat panel.


Disadvantages
• Vulnerable to shorts due to contamination of substrate surface by dust.
• Voltage drops.
• Mechanically fragile.
• Potential not yet realized.

Applications

Polymer light-emitting diodes (PLED) can easily be processed into large-area thin films using simple and inexpensive technology. They also promise to challenge LCD's as the premiere display technology for wireless phones, pagers, and PDA's with brighter, thinner, lighter, and faster features than the current display.

SPONSERED BY :- e-soft technologies and Cetpa