Technical / Research - Page 27

Update: It turns out that these are actually LEDs and not OLEDs in this video - and PolyPhotonix indeed developed both LED and OLED prototypes.

UK-based PolyPhotonix, in collaboration with the Centre for Process Innovation (CPI), developed a wearable electronic blanket that uses printed OLED lighting to administer a phototherapy for the possible treatment of a number of skin conditions such as acne, psoriasis, eczema and jaundice. The blanket could also be used for wound healing and anti inflammatory treatments.

The blanket uses small flexible OLED devices. The treatment schedule and dosage of the light are programmable - so the treatment can be optimized and also be used for different conditions. The prototype blanket that was demonstrated also includes sensors and can log and record the usage.

Researchers at the University of Michigan developed a new deep-blue energy-efficient phosphorescent OLED (PHOLED) emitter. The researchers say that this is the brightest deep-blue PHOLED ever reported - in fact it is about 10 times brighter than previous deep-blue PHOLEDs. The lifetime of this material is still very low, and future research will attempt to stabilize the molecule.

The new emitter is based on a N-heterocyclic carbene iridium-III complex molecule. This is an efficient compound because its design reduces the chances that light-emitting excitons will either get lost as heat or destroy the compound itself. This research is sponsored by Universal Display Corporation and the U.S. Air Force.

Researchers from Arizona State University (ASU) are developing high-qualify OLED lighting devices that emit no UV light. Such OLEDs will be particularly useful in museums, art galleries and similar places, since UV light inhibits the human eye in clearly discerning color variations and the texture of objects.

The researchers recently received a $875,000 grant from the US DoE to expand the research. The team is collaborating with Universal Display to develop OLEDs that use a single emissive material to create white light - and not a white OLED device that uses a combination of red, green and blue emissive materials (or yellow and blue).

Researchers at the US DoE's Ames Laboratory developed a near ultra-violet (UV) OLED device that can be used as an on-chip photosensor. They say that this is the first time that light can be captured and manipulated at around 400 nm - or near the invisible end of the spectrum.

The researchers envision a tiny chip that can act as a whole spectrometer - so it can measure the absorption or luminescence spectrum of anything that can absorb or emit light. There are many applications for such a sensor - for food safety, water quality, medical diagnosis and more. This near-UV OLED development is a step towards that goal.

Finding an alternative for ITO as a transparent electrode is one of the major flexible OLED challenges. A few days ago, The Faunhofer Institute FEP demonstrated an OLED device that has a graphene electrode, developed as part of project GLADIATOR.

The Fraunhofer developed the device in collaboration with Spain-based Graphenea, which supplied the CVD-produced monolayer graphene. Graphene-Info posted an interview with the project's coordinator who further explains the technology, why graphene is promising and what are the challenges that still has to be solved before graphene transparent electrodes can be commercialized.

The Faunhofer Institute FEP is going to demonstrate an OLED device that has a graphene electrode, developed as part of project GLADIATOR. The Fraunhofer developed the device in collaboration with Graphenea, which supplied the CVD-produced monolayer graphene.

This first demonstrator is a small OLED device. The partners in this project now aim to create a larger-sized OLED with an active area of 42 cm². They also plan to develop a fully-flexible transparent OLED, with an active area of 3 cm².

Professor Bjorn Lussem from Kent State University received a $180,000 grant from the Binational Science Foundation to continue his development of an OLED display that is driven by a vertical organic transistor.

Professor Lussem explains that vertical transistors use less voltage so they are more power efficient. A vertical design also means you can make higher density displays. Professor Lussem's partner in this reserach is Professor Nir tessler from Israel's Technion institute for technology.

US-based Pixelligent has been researching light extraction materials for OLED lighting panels for a long time, and the company now officially announced a new family of OLED lighting products.

The PixClear Zirconia nanocrystal family of high index materials enable revolutionary light extraction and efficiency for a wide variety of OLED Lighting applications. PixClear materials can be incorporated into OLED lighting panels as an internal light extraction and smoothing layer, delivering more than twice the amount of light currently extracted in OLED lighting devices.

Researchers from Korea's Ulsan Institute of Technology announced that they have developed a new technique that can improve the efficiency of Iridium-doped phosphorescent emitters by more than 30 times.

The team explained that this dramatic increase in efficiency was achieved by a new method to synthesize molecules - which resulted in "stronger" molecules. More precisely, the researchers created an emitter molecule in which the two carborane units were thethered by an alkylene linker.

This is a guest post by SCM's business developer Fedor Goumans

To further improve the efficiency and life-time of organic light-emitting diodes (OLEDs), ultimately the properties of underlying materials need to be tweaked at the molecular level. In materials science, as in other fields, modeling has become a more wide-spread tool integrated with experiments for a holistic research & development approach.

In particular, high-throughput screening computational screening may considerably reduce experimental costs for synthesizing and testing new materials. At the molecular level there are a few properties that are important for OLED life-time and efficiency. A simplified set up for an OLED device is depicted in Figure 1. The charge mobility and light emission properties can be predicted with computational chemistry, as explained below.