OLED lighting

What is an OLED?

OLED is short for organic light emitting diode. OLEDs consist of several different material layers, and each of these layers has a specific task. Beginning with the carrier material, today usually glass but in some cases metal, and finishing with the encapsulating cover glass, 10 different layers are not unusual.

Among these are in some cases transparent electrode materials, electron transporting materials and the actual organic emitter materials. Light generation takes place within these organic emitter materials. The materials are applied in very thin layers (sometimes consisting of just a few nanometres) in planar fashion onto the carrier materials to create a homogeneous, luminous sequence of layers.

The current state of development and -future outlook

OLED technology is in general experiencing a very positive development. Currently OLED glass tiles are available in sizes up to 15 cm x 15 cm that emit light in one direction, and OLED efficiency levels range from 30 to 60 lm/W. These efficiencies will increase soon. In the same time period it will also be possible to reduce costs and further develop unique properties such as transparency and flexibility. Major manufacturers are investing many millions in production plants and new business models.

Large-scale installations with OLED are being aimed at and are one of the approaches in helping OLED to achieve greater market acceptance. Although OLEDs are currently still expensive, quantity is used to impress. Several OLED producers as well as luminaire manufacturers link their installations with supplementary features (e.g. sequential control, interaction or kinetics). In the near future OLED will be strongly customer-oriented and will find applications in projects/project luminaires. The manufacturers are "pushing" the technology and hope for the "pull" of the lighting industry.

General construction of an OLED

OLEDs emit light only in the visible range. Depending on the specific combination of individual layers, they emit monochromatic (single-colour) light or white light. Warm white and cool white colour tones are possible. The light is emitted diffusely, homogeneously and almost Lambertian, in one direction (with non-transparent OLEDs) or two directions (with transparent OLEDs). The functional principle is similar to that of LEDs.

Electrons and holes recombine with each other with OLEDs as well to generate energy in the form of light. As with LEDs, band structures exist in whose transition areas the recombination processes take place. The production of OLEDs is under cleanroom conditions and is implemented by vaporization under high vacuum. This is a very elaborate and expensive complex process, and even the smallest of impurities can damage the organic materials. The layer construction must therefore be optimally protected from external influences such as oxygen, water vapour and other particles by very good encapsulation with a cover glass.

Cooperative OLYMP research project

The aim of OLYMP is to lead OLED technology to market maturity for the general lighting mass market. The technological advance gained by the cooperation partners in the organic LED sector should be maintained, therefore enabling OLED materials and series products from Germany. A high level of innovation is needed to defend this peak position with the technological core topics of higher energy efficiency and costs that are simultaneously suitable for the lighting market.

Following successful market launching, it will be increasingly necessary to introduce initial small series for increasing the acceptance of this new wide-area light technology to help achieve wide market penetration. As part of the research project, TRILUX will present the results in the form of luminaire demonstrators.In a similar way to LED development, much momentum can be taken over from the display industry with the OLED sector. The costs for materials will decrease, and acceptance for this technology will significantly increase in the sector.