SEMINAR ON

LIGHT EMITTING polymers

MONITORS

Monitor is the component of your computer system that displays the messages and data being processed and utilized by the computer's CPU.

The two types of monitor technologies available to consumers are CRT Monitors LCD Monitors

CRT Monitor LCD Monitor

• bigger and bulkier

• consume more power

• more expensive

• problem of viewing angles

• less accurate color replication

• prone to screen flicker

Light Emitting Polymers• An Organic Light Emitting Diode (OLED), also Light

Emitting Polymer (LEP) and Organic Electro Luminescence (OEL), is any Light Emitting Diode (LED) whose emissive electroluminescent layer is composed of a film of organic compounds.

• The layer usually contains a polymer substance that

allows suitable organic compounds to be deposited.

• The resulting matrix of pixels can emit light of different colors.

What Is Organic Light Emitting Diodes (OLED)?

                                          

        Organic Light Emitting Diode technology, pioneered and patented by Kodak/Sanyo, enables full color, full-motion flat panel displays with a level of brightness and sharpness not possible with other technologies.   

 

How OLED Works

• The basic OLED cell structure consists of a stack of thin organic layers sandwiched between

a transparent anode and a metallic cathode

• The organic layers comprise a hole-injection layer, a hole-transport layer, an emissive layer,

and an electron-transport layer

• When an appropriate voltage is applied to the cell, the injected positive and negative charges

recombine in the emissive layer to produce light

OLED Structure

Bottom emission uses a transparent or semi-transparent bottom electrode to get the light through a transparent substrate. Top emission uses a transparent or semi- transparent top electrode to get the light through the counter substrate.

OLED Structures

Bottom emission/Top emission

Transparent OLED

Transparent organic light-emitting device (TOLED) uses a proprietary transparent contact to create displays that can be made to be top-only emitting, bottom-only emitting, or both top and bottom emitting (transparent). This technology is used in Heads-up displays

Stacked OLED

Stacked OLED (SOLED) uses a pixel architecture that stacks the red, green, and blue subpixels on top of one another instead of next to one another, leading to substantial increase in gamut and color depth,and greatly reducing pixel gap

Inverted OLED

In contrast to a conventional OLED, in which the anode is placed on the substrate, an Inverted OLED (IOLED) uses a bottom cathode that can be connected to the drain end of an n-channel

1.Material technologies

Polymer light-emitting diodes Phosphorescent materials

2. Patterning technologies

Patternable OLED Inkjet Laser patterning

3. Backplane technologies

Small molecules

TECHNOLOGY

There are two forms of OLED displays:  Passive-matrix and Active-matrix.

 Passive and Active Displays 

                                                                  

The Passive-Matrix OLED display has a simple structure and is well suited for low-cost and low-information content applications such as alphanumeric displays.It is formed by providing an array of OLED pixels connected by intersecting anode and cathode conductors

The Active-Matrix OLED display has an integrated electronic back plane as its substrate and lends itself to high-resolution, high-information content applications including videos and graphics.This form of display because of its high carrier mobility, provides thin-film-transistors (TFT) with high current carrying capability and high switching speed.

Advantages:       

  Viewing Angles

 High Resolution

Electronic Paper   Production Advantages

Video Capabilities

  Hardware Content

Power Usage

Robust Design

OLED  LCD

        

Disadvantages

Engineering HurdlesEngineering Hurdles

  Color Color

Overcoming LCD’sOvercoming LCD’s

            The OLED technology faces a bright future in the display market, as the ever-changing market environment appears to be a global race to achieve new success .Because production is more akin to chemical

processing than semiconductor manufacturing, OLED materials could someday be applied to plastic and other materials to create wall-size video

panels, roll-up screens for laptops, and even head wearable displays.

Future Outlook:

 

• The Organic Light Emitting Diode forms of display still have many obstacles to overcome before it’s popularity and even more importantly, its reliability are up to par with standards expected by consumers. 

• Although the technology presents itself as a major player in the field of displays, overcoming these obstacles will prove to be a difficult task. 

•   For all we know and can hope for…OLED’s could change the ways in which we see things.

CONCLUSION