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’ GaN-on-Si-buffer layers, which will be fine-tuned during the collaboration to optimize the performance of KAUST’s red LED stack.
Researchers from the University of Waterloo in Canada developed a new transfer and bonding method to deposit a flexible microLED array on plastic substrates.
The technique, referred to as a "paste-and-cut", starts with temporarily bonding the LEDs on a process/handle wafer onto a glass substrate (the paste step). The LEDs are then released (cut) to the flexible substrate. This approach allows the LED to be optimized and then combined with other materials.
Researchers from Seoul National University (SNU) in collaboration with KAIST, SAIT and the Korea Photonics Institute developed a new method to deposit MicroLEDs on sapphire nano-membranes which enables chip singulation without an etching process. This method can enable higher efficiency MicroLED devices.
The researchers say that this method improves the internal quantum efficiency (IQE) of the microLEDs by 44% compared to standard GaN microLEDs produced on regular planar substrates. The microLEDs also featured a reduced dislocation density (by 59.6%). According to their tests, the microLEDs provided 3.3X the photoluminescence compared to regular microLEDs.
Researchers from the University of Sheffield a new fabrication process for green InGaN microLEDs that achieves high brightness compact microLED arrays.
Today most green InGaN microLEDs are produced by combining a standard photolithography technique with subsequent dry-etching processes on a standard III-nitride LED wafer. The researchers found a way to avoid the dry-etching processes which damage the surface the resulting LEDs. In the new process, the InGaN stack is direectly grown within pre-patterned micro-hole arrays through a thin (500nm) SiO2 layer serving as a GaN template over the epitaxial wafer.
MicroLED-Info and Perovskite-Info are happy to announce the 2020 edition of The Perovskite Handbook. This book is a comprehensive guide to perovskite materials, applications and industry, and it is now updated to January 2020 and lists recent developments and new companies, initiatives and research activities.
Perovskites are an exciting class of materials that feature a myriad of exciting properties. Perovskites are now entering the display market, with applications in quantum dots, LEDs, lasers and more.
