Technical / Research - Page 23

EU researchers demonstrate a flexible 2 x 1 cm OLED lighting panel with graphene electrodes

The European GLADIATOR project, led by the Fraunhofer Institute, developed a functional flexible OLED lighting panel based on graphene electrodes. This new panel is 2 x 1 cm in size - much larger the previous prototype developed as part of that project last year.

OLED device with graphene electrodes (Gladiator, Jan 2017)

The GLADIATOR project will conclude in April 2017. In the following months, the researchers aim to improve the graphene electrode by minimizing the impurities and defects that occur during the transfer of the graphene sheet. The project's leader, Beatrice Beyer, estimate that such OLEDs with graphene electrodes could be commercialization within 2-3 years. In September 2015 Graphene-Info posted an interview with Beatrice, discussing the technology behind this project.

Read the full story Posted: Jan 04,2017

Vacuum chamber impurities found to decrease the lifetime of OLED panels

Researchers from Kyushu University discovered that lifetime of OLED displays is compromised during the evaporation production process due to small amounts of impurities in the vacuum chamber.

Vacuum impurities effect on OLEDs (Kyushu)

The researchers examined the production process and found that there are many impurities floating in the vacuum even when the deposition chamber is at room temperature. They found a strong correlation between the time the OLED is placed in the deposition chamber and its lifetime.

Read the full story Posted: Dec 29,2016

Researchers at Tohoku University develop a super flexible liquid-crystal device

Researchers at Tohoku University in Japan developed a super flexible organic liquid crystal device, which they say are promising for next-generation highly-flexible LCD displays. The new device is formed from ultra-thin plastic (polyimide) substrates that are firmly bonded by polymer wall spacers.

Super flexible LC structure (Tohoku University)

The transparent polyimide substrate (made by Mitsui Chemicals) are about 10 um thick each, and feature heat resistance and the ability to form fine pixel structures, including transparent electrodes and color filters. The refractive index anisotropy is extremely small, making wide viewing angles and high contrast ratio possible.

Read the full story Posted: Dec 01,2016

KAIST researchers develop an OLED device on a fabric substrate

Reserachers from Korea's KAIST institute developed a process to deposit OLED displays on textile substrates. The substrate uses fabrics made from several-micrometer-thick fibers. Using a planarization process the researchers created a fabric as flat as a piece of glass.

OLED device on a textile substrate (KAIST)

 

The OLED was deposited on this flat fabric using regular evaporation equipment. Using thin-film encapsulation, a lifetime of 1,000 hours was achieved. The textile OLED is much more flexible than a plasic based one, and may find uses in wearables. Of course the performance needs to be increased and this just a research project at this stage.

Read the full story Posted: Nov 24,2016

The Holst Center developed a Spatial-ALD TFT deposition process

Researchers from the Holst Centre developed a new process to deposit semiconductor layers with better performance and high throughput than PVD-based process. the new process is based on scalable, atmospheric-pressure process spatial-ALD.

Display transistors deposited by sALD image

The Holst Centre used sALD to deposit IGZO backplanes that achieved charge carrier mobilities of 30 to 45 cm2/Vs. The researchers say that similar backplanes deposited with PVD (supttering) achieve about 10 cm2/Vs. The sALD layers also exhibited low off current, switch-on voltages around 0 V and excellent bias stress stability.

Read the full story Posted: Nov 24,2016

Sunic Systems managed to achieve 1,500 PPI Using plane source evaporation

Sunic System recently unveiled a new evaporation-FMM based AMOLED system that enables high resolution deposition - Sunic says it will enable PPI up to 2,250 PPI. Sunic's new technology makes use of a plane source for evaporating OLED materials, as opposed to the currently-used linear source. Such high resolution displays will be very useful for VR applications.

Sunic: plane-source evaporation (Nov-2016 slide)

Sunic System now announced that it succeeded in implementing 1.1um shadow distance by using the new plane source evaporation and 100um shadow mask. Such a small shadow distance can achieve 1,000 to 1,500 PPI resolutions. The company's next step is to lower shadow distance to 0.37um - which will indeed enable 2,250 PPI and 11K high-resolution mobile AMOLEDs.

Read the full story Posted: Nov 11,2016

Researchers develop a cheap and efficient MgO-based OLED encapsulation layer

Researchers from South China University of Technology (SCUT) demonstrated a new MgO-based OLED encapsulation layer. The researchers say that MgO provides an efficient barrier at a low cost, and can be deposited in low temperatures.

MgO OLED encapsulation tests (SCUT 2016)

The researchers say that this is the first time that MgO is used for OLED encapsulation, but this material has a number of advantages - a low refractive index, a wide bandgap, high dielectric constant, high chemical stability and the lack of UV irradiation treatment requirements.

Read the full story Posted: Nov 11,2016

The Fraunhofer FEP developed an ultra-low power OLED microdisplay

Researchers from the Fraunhofer FEP announced a new development that can reduce the power consumption of OLED microdisplays. The power reduction is enabled by new chip and control electronics, that now only handles pixel changes and does not refresh the entire display all at once.

Fruanhofer ultra-low power OLED microdisplay photo (11/2016)

The researchers say that this development enabled a drastic reduction in power consumption - which is somewhat surprising. The new microdisplays (which are monochrome - green) use 1 to 4 mW, which they say is a fraction of the power consumed by the Fraunhofer's previous generation display - a color (WOLED+CF) bi-directional OLED (so this is not a fair comparison of course).

Read the full story Posted: Nov 02,2016

The DoE publishes a CALiPER report with photometric testing of four OLED luminaries

The US DoE published a new CALiPER report made by the PNNL laboratory, with photometric testing, laboratory teardowns and accelerated lifetime testing of OLED luminaires. As you can see in the photo below, the four luminaries (from top-left, clockwise) are the OTI Aerelight, Acuity Brands Chalina and Acuity Brands Nomi (single panel and dual panel).

CALiPER 24 OLED luminairies

The report contains a lot of interesting information (see the link below to access the PDF). The PNNL researchers find that efficiency of OLED luminairies is still low compared to LED lamps - ranging from 23 lm/W to 45 lm/W. The OLED panels themselves are more efficient (42 - 55 lm/W) but the reduction in efficiency is mostly due to very inefficient transformer and driver selections and combinations.

Read the full story Posted: Oct 28,2016

Fluxim releases a new software tool to simulate large area OLED panels

Switzerland-based R&D tools provider Fluxim released a new simulation tool called Laoss. Laoss is aimed specifically for large area organic electronic devices - such as large OLED display and lighting panels and perovskite solar cells.

The Laoss software is used to design optimal electrode lay-outs of any shape with and without current carrying grids. Fluxim says that a carefully designed electrode layout avoids non-uniformities that arise due to the resistance of the electrode and charge injecting layers. Laoss tool can be used in combination with Fluxim’s Setfos software to design the layer stack of the OLED/PV device as well as with results from the Paios measurement platform.

Read the full story Posted: Oct 24,2016