Post on 21-Jul-2015
CONTENT
Introduction History Principle AMOLED Components Working Manufacturing of AMOLED Comparison Applications and future prospects Advantages Disadvantages Conclusion
INTRODUCTION
Active-Matrix OLED (Active-matrix organic light-emitting diode or AMOLED) is a display technology .
AMOLED is type of OLED . OLED describes specific type of thin display
technology and Active-Matrix refers to the technology behind the addressing of pixels.
An OLED is any LED whose emissive electroluminescent layer comprises a film of organic compounds
The layer usually contains a polymer substance that allows suitable organic compounds to be deposited.
They are deposited in rows and columns onto a flat carrier by a simple printing process.
The resulting matrix of pixels can emit light of different colors.
AMOLEDs have full layers of cathode, organic molecules and anode, but the anode layer overlays a thin film transistor (TFT) array that forms a matrix. The TFT array itself is the circuitry that determines which pixels get turned on to form an image.
AMOLEDs consume less power than PMOLEDs because the TFT array requires less power than external circuitry, so they are efficient for large displays. AMOLEDs also have faster refresh rates suitable for video. The best uses for AMOLEDs are computer monitors, large-screen TVs and electronic signs or billboards.
HISTORY The first EL from a an organic molecule, anthracene,
was reported by Pope and coworkers in 1963 .
The active matrix technology is invented by Bernard Lechner in 1975
PRINCIPLE
Electroluminescence (EL) is an optical phenomenon and electrical phenomenon in which a material emits light in response to an electric current passed through it, or to a strong electric field
The AMOLED display consists of a matrix of OLED pixels, each having an anode, cathode and a layer of organic material between them.
These pixels are activated by a thin film transistor array which controls the current to each pixel, enabling it to be activated and when current flows through it, light is generated.
Typically two transistors are used for each pixel - one to turn the charge to the pixel on and off, and a second to provide the constant current.
This eliminates the need for the very high currents required for passive matrix OLED operation
Manufacturing Of AMOLED
The biggest part of manufacturing AMOLEDs is applying the organic layers to the substrate. This can be done in three ways:
Vacuum deposition or vacuum thermal evaporation (VTE)
Organic vapor phase deposition (OVPD)
Inkjet printing
AMOLED LCD PLASMA
• Potentially the lowest cost. • Medium cost. • Highest cost
• Consumes lowest power • Lower Power consumption than plasma
• Highest power consumption
• Self emissive. • Requires backlight. • Requires backlight.
• Displays wider color range. • Color range not good. • Displays a very deep black.
• No screen burn potential • No screen burn potential • Screen burn potential
• Shorter overall lifetime • Backlight bulb typically requires replace at around 30 k hours
• Half life ~60k hours
Comparison:
FUTURE PROSPECTS
Curved AMOLED displays
Wearable AMOLEDs
Transparent AMOLEDs embedded in windows
AMOLEDs in car windshields
Realizing Concept models of various mobile devices
Higher contrast ratio and sun readability
Large viewing angle
Brightness
Less Power consumption
Faster response
CONCLUSION
Limited use caused by degradation of materials.
AMOLED will replace current LED and LCD technologies
Flexibility and thinness will enable many applications