oleds, ppt..pptx

7/22/2019 OLEDs, ppt..pptx

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OLEDsOrganic Light-Emitting Diodes

Rhiza Lyne E. Villones


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New Technology for Flat Panel Displays(FPDs) Pictures


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Current Technologies

Liquid Crystal Displays (LCDs)

PICS

Plasma

PICS


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General Shortcomings of FPDs

Energy consumption

Manufacturing cost

Limited to glass


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Deficiencies

LCDs

Does not look very real

Response delay

Plasma

Affected by ambient light


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OLEDs Outline

Background

Luminescence

History

Applications

OLEDs Structure Classes

Future Research Anticipated Products


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Luminescence

Photoluminescence, PL

Optical excitation

Fluorescence

Phosphorescence


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Luminescence

Electroluminescence, EL

Electrical excitation


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Types of Light-Emitting Diodes, LEDs

Inorganic, LEDs

Polymer, PLEDs

Organic, OLEDs


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History


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Device Structure


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Terms

Luminance, or Light Output Luminous intensity per unit area, cd/m2

Quantum efficiency Photon/electron ratio

Power efficiency Radiance per unit electric power, lm/W

Driving (turn-on) voltage Minimum voltage required for emission, V

Glass transition temperature Rigid amorphous material


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Desired Properties for OLEDs

Organic molecule

Amorphous, with high glass TT (>100degC)

Device

Luminance, >20,000 cd/m2

Q. efficiency, >4%

P. efficiency, >20 lm/W Turn-on voltage, 10,000 h


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Enhancing Performance


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Structure Classes

Hole Transport Layer, HTL

Arylamines, Isoindole

Electron Transport Layer, ETL

Oxadiazole, Imidazole

Emissive Layer, EML

Metal chelates Fluorene, Carbazone, Maleimide

Anthracene


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Future Research

Further increased stability and lifetime

Amorphous films with high glass TT

Increased Q. and P. efficiencies

Organic compounds with high quantum yield

More pure RGB for full-color displays


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Future Applications

Transparent OLEDs

Electronic paper

Tow-sided OLED


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oleds, ppt..pptx

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