Technical / research - Page 6

Researchers from the Korea Institute of Machinery and Materials (KIMM) have developed a stretchable microLED display, that can be stretched in both directions. The researchers say that the display can stretched by up to 25% without distortion to the image.

The researchers report that they have managed to successfully fabricate a 3" microLED display. This was achieved by using metamaterials with unique mechanical properties that do not exist in nature - mainly that if they are stretched in one direction, they also stretch in the perpendicular dimension, and so the display is not distorted. They term the display a 'metadisplay'.

Quantum Dots developer Nanosys announced a joint-development agreement with OTFT backplane developer SmartKem, to work on low-cost OTFT based microLED displays.

1.6-inch LTPS microLED prototype (glo)

The two companies will develop displays that utilize SmartKem's OTFT backplane and Nanosys' GaN microLED technology. Last year Nanosys acquired glo, which developed the microLED tech.

Korea-based LED developer Seoul Viosys announced two microLED related breakthroughes developed together with researchers from the University of California, Santa Barbara (UCSB).

First of all, the researcher succeeded in developing blue and green micro LEDs with 1 μm diameter. Second, they have managed to overcome challenges of decreased EQE in red microLEDs at 70um. The EQE of the 70um red microLEDs have been increased by 150% compared to the company's previous designs.

US-based amorphous-metals based display backplane developer Amorphyx was awarded a $256,000 US NSF SBIR phase I grant towards a proof-of-concept demonstration of the company's 211 pixel circuit for AMOLED and microLED applications.

Amorphyx says that its 211 pixel circuit leverages the unique properties of the AMNR and IGZO AMeTFT device technologies to both improve upon the variable image refresh rate and power consumption improvements of LTPO while dramatically simplifying the pixel circuit's functionality and manufacturing. The Amorphyx backplane meets and exceeds LTPO performance while eliminating the LTPS TFT technology that drives the complexity of manufacturing LTPO backplanes.

Researchers from Korea's Electronics and Telecommunications Research Institute (ETRI) developed a new process to produce microLED displays, which they say can be highly cost effective.

The new process is based on a novel film-like material developed at ETRI, called SITRAB. Using lasers, the process apparently detaches the microLED from the original epiwafer and bonds it to the SITRAB film in the same process step. The LEDs are then transferred to the final target backplane.

Researchers from King Abdullah's University of Science & Technology (KAUST) in Saudi Arabia developed GaN and InGan red microLED devices that are highly efficient.

The researchers managed to increase the efficiency of their previous design by a new chemical treatment that removes damages at the microLED sidewalls (created during the fabrication process) and also retains the high crystal quality at the InGaN and GaN sidewall interfaces.

Researchers from the University of Texas at Dallas developed a new method to create highly flexible microLED chips, that can be folded and twisted. The LEDs are detachable, and can be attached to almost an surface.

The researchers used remote epitaxy, to grow the LED crystals on a sapphire crystal substrate, coated with a one-atom layer of 2D graphene, which prevents the LED to stick to the sapphire substrate.

Kyocera and OSRAM have jointly designed a new hybrid current and PWM driving technology for microLED displays. The two companies says that this new driving scheme can be used to avoid using lower pixel currents through microLED chips, which reduces the deviation of the luminance and the color shift at lower grayscale levels.

Kyocera has presented a 3.9" full-color microLED display on an LTPS backplane that showed excellent performances that proves the validity of the new driving technology.

GE announced that it has been able to deposit its red phosphor (PFS-KSF) material using an inkjet printing process on a plastic substrate. This technology can be applied in future microLED and miniLED displays.

GE is also sampling a new green phosphor, that together with the red phosphor can attain 88% Rec. 2020. The company reveals that almost 40 billion LEDs with its PFS-KSF material were sold into commercial displays.

GaN-on-Si IP developer ALLOS Semiconductors announced it is collaborating with with Prof. Ohkawa and his team at King Abdullah University of Science and Technology (KAUST) to develop high efficiency nitride-based red LEDs on large diameter silicon substrates.

Prof. Ohkawa and team have developed an indium gallium nitride (InGaN)- based red LED stack with low forward voltage of less than 2.5 V and high efficiency by using local strain compensation and a modified MOCVD reactor design. ALLOS and the KAUST team will combine their unique technologies to handle strain and optimize crystal growth conditions for GaN-on-Si and red LEDs. To this end, the KAUST team will grow its red LED stack on top of ALLOS's GaN-on-Si-buffer layers, which will be fine-tuned during the collaboration to optimize the performance of KAUST's red LED stack.