Technical / Research - Page 25

Researchers from Turkey demonstrated a display prototype that is printed on paper (using graphene inks). This was a very simple device, but potentially such a technology could be used to create a foldable display with interesting optoelectronic properties.

To create this display, the researchers used electro-modulation of the optical properties of the multilayer graphene via blocking the interband electronic transitions. The researcher report that the paper display has high optical contrast and a fast response time.

In 2011 the University of Florida announced a new organic-TFT backplane/emitter technology called CN-VOLET. The University spun-off the technology into a company called nVerPix, with funding from Nanoholdings.

We have talked to nVerPix in the past and updated on the technology back in 2013. The nVerPix team presented their technology at SID's DisplayWeek - and it won the "best prototype" awarded. nVerPix demonstrate a working mono-color (green) 320x240 2.5" display. The aperture ratio is 70% and the brightness is over 500 nits.

Samsung Display developed a new high-resolution OLED display, specifically for VR applications. The 5.5" panel, on display at SID DisplayWeek, sported a 3840x2160 resolution - or 806 PPI. The panel offered a brightness of 350 nits and a color gamut of 97% adobe RGB.

This is the highest resolution mobile phone sized OLED ever demonstrated, and it exactly matches the highest resolution LCD - Sharp's 5.5" 806 PPI IGZO panel unveiled in 2015. Samsung's display probably uses some sort of PenTile architecture, though, so actual sub-pixel count is smaller.

Researchers from Korea's KAIST institute developed a rollable OLED device that uses graphene-based electrodes. The researchers say that the new OLED is much more durable when bent compared to current devices made with ITO electrodes.

The electrodes were made from a stack of materials - titanium oxides, graphene and conductive polymers. The new OLEDs were also brighter than current devices, and with a higher color gamut. This was achieved by maximizing the resonance within the OLED.

GJM developed a new 300mm roll-to-roll deposition system that can directly deposit both organic and inorganic materials on plastic materials - and be used to mass produce flexible OLEDs. The system was developed in collaboration with the Korea Institute of Machinery & Materials.

GJM says that its R2R system can speed up production times compared to current systems - by about 50% (GJM says that production amount can be improved by 1.5 times) - and so contribute to lower cost production. The system can be used to produce both OLED display and lighting panels.

Japan Display (JDI) announced that it has signed a technology development agreement with Semiconductor Energy Laboratory (SEL) regarding the development of Oxide-semiconductor backplane technology for next-generation displays, including OLED displays.

SEL's backplane technology is called c-axis aligned crystal (CAAC), which has been co-developed with Sharp. CAAC is based on an IGZO thin-film that has a novel crystal structure.

Universal Display developed a new AMOLED structure that is a sort of WOLED - RGB hybrid structure. The idea is to use a large blue sub-pixel and a large yellow sub-pixel that is split into three areas - unfiltered and red and green filtered.

This structure is easier to deposit compared to a true RGB AMOLED (that requires very fine patterning of red, green and blue subpixels) but increase the aperture ratio compared to a WOLED architecture (which LG for example uses in its OLED TVs) - which increases the lifetime and color gamut of the display.

Researchers from St. Andrews University in the UK used a micro blue OLED display to active individual live cells from a human embryonic kidney cell line that were tweaked to produce a light-sensitive protein.

The researchers say that this ability to use OLEDs to activate individual cells may enable cell-specific optogenetic control in cultured neuronal networks, brain slices, and other biomedical research applications. They say that OLEDs are an "ideal platform technology for investigating and controlling biological processes with single cell resolution".

The Fraunhofer FEP announced new large-area flexible OLED lighting panel prototypes that have been fabricated on ultra-thin glass and encapsulated with a ultra-thin glass foil in the same process.

The new process developed at the Fraunhofer institute is able to deposit OLEDs on the flexible glass and encapsulation it using an additional flexible glass layer - all in a a single roll-to-roll manufacturing step.

Germany-based OLED emitter developer Cynora announced it has made significant progress in its highly efficient blue OLED emitter material developments during the last 6 months. The company's materials are not yet ready for commercialization, but the company believes it is on its way.

Cynora develops TADF-based emitters, focusing on blue-color emitters. Cynora has developed deep blue material reaching an EQE of 16.3% (at 100 cd/m²) compared to 3% reached in October 2015, a factor 5 improvement in six months.