OLEDs for lighting applications

Abstract

Organic light emitting diodes (OLEDs) provide potential for power-efficient large area light sources that combine revolutionary properties. They are thin and flat and in addition they can be transparent, colour-tuneable, or flexible. We review the state of the art in white OLEDs and present performance data for three-colour hybrid white OLEDs on indexmatched substrates. With improved optical outcoupling 45 lm/W are achieved. Using a half-sphere to collect all the light that is in the substrate results in 80 lm/W. Optical modelling supports the experimental work. For decorative applications features like transparency and colour tuning are very appealing. We show results on transparent white OLEDs and two ways to come to a colour-variable OLED. These are lateral separation of different colours in a striped design and direct vertical stacking of the different emitting layers. For a striped colour tuneable OLED 36 lm/W are achieved in white with improved optical outcoupling.

Degradation Mechanisms and Reactions in Organic Light-Emitting Devices

“…Figure shows the evolution of lifetime compared at the same initial luminance of 1000 cd/m 2 . ,,,,,,,,− In case of missing data of the initial luminance, we used the simple extrapolation of the available data with eq and n = 1, even though it can lead to an overestimation of the lifetime data. Because of the fact that this extrapolation is only necessary for data mainly collected in the last century, this overestimation may be a tribute to the pioneering work of our colleagues.…”

Large white organic light-emitting diode lighting panel on metal foils

“…1,2 This solid state light source is a "green-energy" source with low power consumption and high energy savings without using mercury. It is a low-cost technology that enables many nice applications, such as flexible and shaped panel, large-area sources, and diffuse and planar emission.…”

Performance Enhancement of Organic Light-Emitting Diodes with an Inorganically Doped Hole Transport Layer

“…In quantum mechanics, spin-orbital coupling is the phenomenon of interaction between the spin and the motion of a particle. The spin orbital interaction is proportional to Z 8 , where Z is that atomic number of the atom; therefore, phosphorescence is favorable in the organo-metallic complexes containing heavy metal atoms such as Iridium, Platinum etc.…”

“…OLEDs are also excellent lighting sources for flat-panel displays due to the fact that they can be built over a large area on many types of substrates including flexible substrates. Many companies are currently trying to commercialize the OLED technology [8][9][10][11]. Yet, the technology still has lots of obstacles to overcome before the full potential can be realized.…”