The New OLEDs by Philips

See here an interesting video of the OLED (Organic Light-Emitting Diode) technology from Philips. This new technology is about to enter into our lifes providing a revolution in the concept of televisions, screens and interior lighting.

For more information you can visit the Philips OLED technology Luminable.

ITO Free Electrodes for OLEDS

ITO is the abbreviation of indium tin oxide, the standard transparent conductor for most of commercial optoelectronic devices. There are not many materials being transparent and electrically conductive at the same time, for this reason and for its limited supply, its cost and demand is increasing and it is becoming crucial to find a cost effective substitute.

Researchers from the Ames Laboratory at Iowa State University (USA) have recently published in the Advanced Materials Journal a possible alternative to ITO, based on PEDOT:PSS (poly (3,4-ethylene dioxythiophene):poly(styrene sulfonate)). This conductive polymer has been around for about 15 years, but until recently it was not conductive and transparent enough to be consider as an alternative to ITO. Using a multi-layering technique and special treatments, Joe Shinar and co-workers have been able to fabricate ITO-free OLEDs with enormously improved properties. They report a 44% higher efficiency compared with a standard ITO device.

Another important advantage of PEDOT:PSS versus ITO is that it is more suitable for flexible substrates, which is one of the main benefit of OLEDs versus LEDs. ITO is a ceramic, so more brittle in nature that a polymer. This achievement can lead to more affordable and cost-effective manufacturing of screen and lighting technologies, which are going to be part of our lives in a very near future.

has been around for about 15 years. Until recently, the material wasn't sufficiently conductive or transparent enough to be a viable ITO substitute, Shinar said. But by using a multi-layering technique and special treatments, Cai and his fellow scientists were able to fabricate PEDOT:PSS OLEDs with vastly improved properties.

Read more at: http://phys.org/news/2012-12-scientists-indium-free-light-emitting-diodes.html#jCp

has been around for about 15 years. Until recently, the material wasn't sufficiently conductive or transparent enough to be a viable ITO substitute, Shinar said. But by using a multi-layering technique and special treatments, Cai and his fellow scientists were able to fabricate PEDOT:PSS OLEDs with vastly improved properties.

Read more at: http://phys.org/news/2012-12-scientists-indium-free-light-emitting-diodes.html#jCp

has been around for about 15 years. Until recently, the material wasn't sufficiently conductive or transparent enough to be a viable ITO substitute, Shinar said. But by using a multi-layering technique and special treatments, Cai and his fellow scientists were able to fabricate PEDOT:PSS OLEDs with vastly improved properties.

Read more at: http://phys.org/news/2012-12-scientists-indium-free-light-emitting-diodes.html#jCp

has been around for about 15 years. Until recently, the material wasn't sufficiently conductive or transparent enough to be a viable ITO substitute, Shinar said. But by using a multi-layering technique and special treatments, Cai and his fellow scientists were able to fabricate PEDOT:PSS OLEDs with vastly improved properties.

Read more at: http://phys.org/news/2012-12-scientists-indium-free-light-emitting-diodes.html#jCp

New Solid State Dye Sensitised Solar Cells in Oxford

All-solid state dye-sensitised solar cells (DSCs) have experienced an impressive growth this year. In these cells the liquid electrolyte is replaced by a solid semiconductor, which can be processed from solution and then penetrate easily the nanoporous matrix of the TiO2. These novel semiconductors belong to the perovskites family and they can even act as the light absorber and the hole or electron conductor.

Apart from the Nature paper from Mercouri Kanatzidis' Group, where they show a cell with CsSnI2.95F0.05 exceeding 10% efficiency, Henry Snaith and his collaborators have reported a 10.9 % efficiency DSC based on the CH3NH3PbI2Cl perovskite. Surprisingly this result has been achieved without using TiO2. A nanostructured insulating Al2O3 film serving as a "scaffold" suffices to obtain this outstanding achievement. The perovskite itself conducts electrons more quickly than the TiO2. These results has been recently published in Science and Dr. Henry Snaith has set up a spin-out company from Oxford University to develop and commercialise this novel technology and all the intellectual property created by his group during their intense research. Oxford Photovoltaics is the name of this company that focus its efforts in building integrated photovoltaics.

However, despite the success of these novel devices, the scientific community have expressed concerns about the reproducibility and stability of some of the reported devices. We will probably have to wait some time to see that other groups are able to reproduce these results and they can be produced on a large scale. This final task is now under development at Oxford Photovoltaics.