NIR OLED

Researchers from the Institute for Materials Research (IUMAT) in Belgium have utilized a green OLED and five organic NIR photodetectors, to create a tiny monolithic upconvertor, that turns invisible NIR images into green light, while preserving the spatial information. All that, without any external power supply.

The device architecture include five organic NIR photodetectors, connected in series, and so the photovoltages build up under NIR illumination to power the integrated OLED. Low lateral charge mobility within the organic layers keeps the photogenerated signal spatially confined as it reaches the OLED, which helps preserve sharp image features that can then be recorded with a conventional or smartphone camera.

Researchers from National Taiwan University, National Yang Ming Chiao Tung University, National Taiwan Ocean University and Academia Sinica used a redesigned C-shaped OLED materials, to create a high-efficiency NIR (1000 nm) OLED device. 

To achieve such a high-efficiency NIR OLED, the researchers replaced a benzene-centered framework with more electron-rich sulfur- and selenium-containing cores. The researchers explain that the stronger electron-rich character promotes intramolecular charge transfer, shifting emission toward 1,000 nanometers, while the rigid C-shaped structure limits molecular relaxation and reduces nonradiative energy loss. The study is published in Advanced Materials.

Researchers from KAIST have developed an OLED-powered wearable (hat like) phototherapy device that has been proven to be effective in suppressing hair follicle cell aging, the main cause of hair loss progression. 

Phototherapy has been getting attention lately as an alternative to drug-based treatment of hair loss, but current devices are rigid and heavy. The new OLED based device, however, is light and flexible. It also emits more uniform compared to LED or laser based systems. 

OLEDWorks, in collaboration with researchers at the University of Michigan and RTX Technology Research Center, have successfully demonstrated a hybrid OLED microdisplay upconversion device that converts near-infrared (NIR) light into visible light with exceptional efficiency and responsiveness.

The newly developed device integrates a multi-stack OLED with a silicon-based photodiode, forming a bistable system that leverages positive optoelectronic feedback. The result is a photon-to-photon upconversion gain of up to 900%, triggered by NIR light intensities below 1 µW/cm²—a performance level that sets a new benchmark for hybrid upconversion systems.

Researchers at Korea's Gachon University, in collaboration with InnoQD and researchers from Chungbuk National University, have developed a new QD-OLED patch that can encourage hair growth. The patch can also measure heart rate at the same time.

The researchers used a flexible OLED device, and covered it with quantum dots that emit near-infrared (NIR) light. The OLED device is a tandem blue OLED device, that offers a high light output. The researchers say that when attached to the head, the patch encourages hair collicle cell growth, with a measured improvement of 23% in hair growth.

Researchers from the University of Michigan, in collaboration with OLEDWorks, has developed an OLED device that converts near infrared (NIR) light into visible light and amplifies it more than 100 times. Compared to current night-vision systems based on image intensifiers, this device could enable a much more efficient and light-weight solution. 

The OLED device integrates a photo-absorbing layer inside the OLED stack, that converts infrared light into electrons. Those electrons are converted into visible light photons via the OLED layers - about five photons are created for each electron, and some of these photons are re-absorbved, converted into more electrons, and then even more photons, creating a great amplification of the absorbed NIR light. 

The following is a sponsored post by ISORG

ISORG is a French company based in Grenoble and Limoges in France, and the world centre of excellence for OPD technology (Organic Photo Diode). With more than 85 patents, ISORG is a technology rich company focused on three main market opportunities: (i) Smartphone fingerprint sensing, (ii) Security applications such as identification and border-crossing markets and (iii) SWIR and NIR CMOS imaging markets for automotive, AR-VR and smartphone applications. It has Gen 2 and Gen 3.5 factory capacity in France and a set of partnerships with leading companies in sensing and authentication. More can be found on ISORG here. In May 2022, CEO Dieter May left the helm of OSRAM Opto Semiconductors to join ISORG.

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Display industry consultant Ian Hendy has interviewed ISORG's CEO Dieter May.

In January 2019 Austria-based Sensor developer AMS announced a new RGB light and proximity sensor IC that can be placed behind an OLED screen, and still accurately measure the intensity of ambient light. Later in 2019, AMS said that the new sensor is a "resounding market success".

In its latest conference call, AMS management said that its behind-the-OLED light and proximity sensing is continuing their adoption in major Android platforms. The company is now shipping very high volumes of sensing solutions. The company is now developing more behind-the-OLED technologies with significant R&D activities.

Professor Homas Teets from the University of Houston has been awarded a $589,000 National Science Foundation (NSF) CAREER Award to explore new synthetic strategies for producing photoactive organometallic compounds.

Specifically, Teets will use the award in three research areas - efficient and long-lasting blue OLED emitters, near-infrared (NIR) emitting compounds and photocatalysts for organic synthesis capable of light-induced electron transfer. The grant will also fund educational projects aimed at children from kindergarten through high school.

The US PTO published a new patent application from Apple that describes an OLED display with a built-in fingerprint reader. The idea is that integrating Near Infrared (NIR) emitters and detectors between the OLED subpixels will enable a much thinner design compared to separate display and detector layers. This also means that there is no need to have a separate reader in the home button as in current iPhones.

The Fraunhofer Institute has demonstrated bi-directional OLED microdisplays back in 2012 that are based on a similar idea - embedding photo detectors (in the visible light range, in that case) within the OLED sub pixels. The latest prototype unveiled in 2015 supports SVGA resolution and a hi-res image sensor. The bi-directional displays are available for sampling.