The structure of the organic layers and the choice of anode and cathode are design to maximize the recombination process in the emissive layer, thus maximizing the light output from the OLED device. The overall thickness of the device is less than 2000 Angstroms.
Organic Light Emitting Diodes (OLEDs) are currently under intensive investigation for use in the next generation of display technologies. The benefits of this technology include wide viewing angle, high emission efficiencies that result in high brightness with low power consumption and low operating voltage. As OLED devices are very lightweight they may be used in cellular phones, notebooks, digital video cameras, digital versatile disc (DVD) players, car stereos, televisions and many other consumer tools that require colour displays.
The OLED is a display technology based on the use of organic polymers as the semiconductor material in Light-Emitting Diodes (LEDs). The organic materials used in OLED devices may include “small” molecules or “macro” polymers. For OLED displays constructed of “small” molecules vapour sublimation in a vacuum chamber is the most convenient deposition technique. In the case of macro polymers solvent coating techniques are often used.
Phase Modulated Spectroscopic Ellipsometry is an excellent technique for the highly accurate characterization of complete OLED stacks. The technique allows the determination of film thickness, optical properties and the effect of dopants to the active layers.
For very high throughput applications where large area flat panels are to be characterized in a production environment the Jobin Yvon FF-1000 ellipsometer has a fully automated sample stage able to accept samples up to 1000 mm x 1000 mm. This accurate, automated thin film metrology tool delivers both unique performance and proven reliability for on-line quality control of production processes.
