Novaled - Page 11

Saint-Gobain and Novaled have demonstrated the feasibility of large area OLEDs, based on a new high-performance metallic anode, with Saint-Gobain Recherche technology and Novaled OLED proprietary developments.

The goal of a two-year research cooperation programme between both partners has been to develop basic technologies for high-performance white OLEDs. Researchers at Saint-Gobain Recherche (SGR) have created a highly conductive transparent electrode Silverduct™, bringing up to 10 times better surface conductivity than traditional ITO (Indium Tin Oxide). Thanks to Novaled PIN OLED™ technology for high efficiency OLEDs, samples were successfully manufactured on large area surfaces. SGR and Novaled now see the possibility to produce homogeneous OLED devices up to 100 cm² which will ease the manufacturing of large OLED lighting products.

Traditional ITO coated glass impedes the race to large area OLED, due to its limited ability to carry current over distances longer than a couple of centimetres. Therefore, for large area OLEDs, the ITO layer must be topped with a thick metallic grid to prevent gradient of light emission caused by the sheet resistance of ITO alone (typically 30 Ohm/sq). The new anode Silverduct™ has a sheet resistance of less than 4 Ohm/sq, thus enabling large area OLEDs without additional metal grids. This is an important step especially for transparent and bottom emission OLEDs in which the metal grid is visible. Additionally, by eliminating the metal grid Silverduct™ offers significant potential for reducing manufacturing costs.

Novaled and Sunic System will develop a new generation of deposition tools and organic materials to improve the deposition process and lifetime of TFE. In this collaboration Novaled will call on its experience in organic structures and skills in organic materials. Sunic System will provide its expert knowledge on both organic and inorganic deposition and encapsulation equipment.

"A new organic material for TFE needs to be developed together with the associated deposition tool," states Gildas Sorin, CEO of Novaled. "The cooperation with Sunic System will bring to market a turn-key solution enabling customers to rapidly ramp-up to high volumes at reasonable costs."

Arcelor Mittal, the world's largest quality steel maker, and Novaled, OLED technology and material provider, have joined forces for a new OLED project. The partners are developing top-emitting OLEDs on flexible substrates for signage and lighting purposes since 2006.

By using Arcelor Mittal's steel plates as substrates, remarkable properties for bendable OLED applications can be achieved. Metallic substrates offer several advantages. Compared to standard glass-sheets they are more robust and durable and commonly produced by roll-to-roll process. This production method can be adapted to a subsequent inline process for OLED-deposition enabling high through-put manufacturing with low tact time. In this collaboration Novaled contributes both its broad technical experience with respect to highly efficient and stable OLED device architectures as well as its material know-how for doped transport layers.

The achievement of a green PIN PHOLED(TM) phosphorescent OLED device in bottom-emission geometry with a CIE of (0.36, 0.61) of above 200,000 hours were attained by combining Universal Display's high-efficiency phosphorescent OLED materials with low-voltage Novaled PIN-OLED(TM) technology and doped transport materials.

"We expect that very low driving voltages below 2.6 V which we already achieved for Ir(ppy)3 can also be obtained for other phosphorescent green emitters" adds Jan Birnstock, VP Technology Transfer.

Novaled achieved unsurpassed lifetime results for top and bottom emitting red fluorescent devices. A red bottom emitting Novaled PIN OLEDTM shows a luminance drop of only 4% after 6000 hours measurement at a starting brightness of 3,700 cd/sqm. The record top emitting red PIN OLED shows a luminance drop of even only 1% after 1,000 hours measurement at a starting brightness of 12,000 cd/sqm. Both OLEDs are down calculated to more than one million hours (corresponding to one century) at starting brightness of 1,000 cd/sqm.

Novaled has also reached significant achievements for blue fluorescent PIN OLEDs: 50,000 hours at 500 cd/sqm in bottom emission answering the request of RGB Active Matrix displays.

In addition, major lifetime improvements have been shown for green phosphorescent PIN OLEDs (100,000 hours at 500 cd/sqm for Ir(ppy)3 based top emission OLEDs). With this value Novaled has doubled its performance for Ir(ppy)3 based green OLED stacks during the last twelve months. We are confident to reach one million hours lifetime with more performing phosphorescent emitting material, says Jan Blochwitz-Nimoth, CTO of the company.

Novaled has achieved groundbreaking results in lifetime, voltage and efficiency of top emitting RGB stacks with its PIN OLED technology. Lifetimes for blue OLEDs are up to 16,000 hours, for red and green up to 100,000 hours at an initial brightness of 500 cd/m². This latest performance means that green OLED devices are now outperforming their bottom emission reference samples by a factor of 2.5. White top emission devices achieved a lifetime of 18,000 hours at a driving voltage of 3 V and a starting luminance of 1,000 cd/m².

The lowest ever reported operating voltage has been realised for green top emission OLED stacks of 2.5 V at 1,000 cd/m². At 95 cd/A, the current efficiency is even higher than for comparable bottom emission devices. These green devices are based on standard emitter material Ir(ppy)3.

Novaled and Heliatek have entered into a licensing agreement concerning the use of Novaled PIN OLED™ technology for solar cell application.

With this agreement, Heliatek will develop high performing organic solar cells using the power efficiency given by the Novaled PIN OLED™ technologies and Novaled unique molecular dopants. Both Companies in addition will cooperate on further developing the organic based photovoltaic technologies.

Universal Display and Novaled presented a joint scientific paper at the International Society of Optical Engineering (SPIE) Optics and Photonics 2006 conference in San Diego, CA. The presentation detailed the achievement of a saturated red PHOLED™ phosphorescent OLED device with a luminous efficacy of 15 candelas per ampere (cd/A) and an operating voltage of less than 4 Volts (V) for a record power efficiency of 12 lumens per Watt (lm/W) all at 1,000 candelas per square meter (cd/m2) brightness.

This milestone was achieved through the combination of Universal Display's high-efficiency PHOLED™ phosphorescent OLED technology and materials with Novaled's low-voltage conductivity doped Novaled PIN-OLEDTM technology and transport materials.

Philips and Novaled reached a new record for the power efficiency of a white OLED, obtaining 32 lm/W with colour coordinates of 0,47/0,45 and a CRI of 88 at a brightness of 1000 cd/m2. That same device structure thereby simultaneously shows a lifetime of more than 20000 hours which is a major achievement for a future commercialization of the OLED technology for lighting applications.

The efficiency of the device was measured using an integrating sphere using only the forward emission cone of the OLED device without attaching any lens or any other volume type luminaire to the OLED device. This is the only method to reliably predict power efficiency values for large area lighting tiles.