Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International



Home > Press > Organic light emitting diodes operated by 1.5 V battery

Fig. 1 (a) Schematic of the device structure and the operating mechanism of OLEDs. (b) Chemical structures.

CREDIT
NINS/IMS
Fig. 1 (a) Schematic of the device structure and the operating mechanism of OLEDs. (b) Chemical structures. CREDIT NINS/IMS

Abstract:
Various properties of organic light-emitting diodes (OLEDs) have been optimized, including current to photon conversion efficiency. An external quantum efficiency exceeding 20%, with internal quantum efficiency of 100%, has been achieved owing to the development of thermally activated delayed fluorescent and phosphorescent materials that manage the spin of excited states. However, the operating voltage of common types of OLEDs is very high; that of an OLED emitting approximately 600-nm light at a luminance of 100 cd/m2, which is a general display condition, is as high as 4.5 V.

Organic light emitting diodes operated by 1.5 V battery

Tokyo, Japan | Posted on January 7th, 2022

Group of Assistant Professor Seiichiro Izawa and Professor Masahiro Hiramoto at Institute for Molecular Science in Japan, and Associate Professor Masahiro Morimoto and Professor Shigeki Naka at University of Toyama in Japan report that an efficient OLED, operable by a 1.5-V battery, that produces bright emission equivalent to luminance of a typical display. The OLED has a smaller turn-on voltage at 0.97 V than the optical energy of emitted photons at 2.04 eV (608 nm), because the OLED is based on upconversion (UC) transition associated with triplet–triplet annihilation that doubles the energy of excited states (Fig. 1). They reveal that the characteristics of charge transfer (CT) state at the interface are key to efficient UC, and the percentage of excited states deactivated by parasitic loss processes during the UC transition is significantly reduced from over 90% to approximately 10% by introducing a highly crystalline acceptor material and an emissive dopant. Consequently, the UC-OLED reaches 100 cd/m2 at a voltage and emission wavelength of 1.33 V and 608 nm (2.04 eV), respectively (Fig. 2a). This is the lowest operating voltage reported for an OLED that achieves a luminance of 100 cd/m2. It was further demonstrated that the UC-OLED can be operated by a 1.5-V battery to realize luminance of 177 cd/m2 (Fig. 2b).

####

For more information, please click here

Contacts:
Hayao KIMURA
National Institutes of Natural Sciences

Office: 81-354-251-890
Expert Contact

Seiichiro Izawa
Institute for Molecular Science

Office: +81-564-59-5537

Copyright © National Institutes of Natural Sciences

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

ARTICLE TITLE

Related News Press

Organic Electronics

Towards high-performance organic optoelectronics with better crystallinity at semiconductor interface: Organic molecular interfaces with minimized structural mismatch and spontaneous electron transfer could open doors to high-efficiency optoelectronics January 14th, 2022

New version of organic electronics for rational management of energy: Researchers of the UMA study the possibility of altering carbon to create chips with a higher capacity than those used nowadays made of electronic silicon December 10th, 2021

Efficient photon upconversion at an organic semiconductor interface November 19th, 2021

News and information

Bioengineered nanoparticles show promise for fibrinogen manufacture, says Journal of Pharmaceutical Analysis study: Scientists engineer a nanoparticle polymer that can selectively bind to fibrinogen in human plasma, presenting a pathway for improved drug development January 14th, 2022

Photon recycling – The key to high-efficiency perovskite solar cells January 14th, 2022

NSF funds Rice effort to measure, preserve quantum entanglement: Physicist Guido Pagano wins CAREER Award to develop tools for quantum computing January 14th, 2022

Tuning the bonds of paired quantum particles to create dissipationless flow: A tunable platform made from atomically thin materials may help researchers figure out how to create a robust quantum condensate that can flow without losing energy January 14th, 2022

Display technology/LEDs/SS Lighting/OLEDs

Fabricating stable, high-mobility transistors for next-generation display technologies December 17th, 2021

New substance classes for nanomaterials: Nano spheres and diamond slivers made of silicon and germanium: Potential applications as nano semiconductor materials September 10th, 2021

Possible Futures

Towards high-performance organic optoelectronics with better crystallinity at semiconductor interface: Organic molecular interfaces with minimized structural mismatch and spontaneous electron transfer could open doors to high-efficiency optoelectronics January 14th, 2022

New photonic effect could speed drug development: Twisted semiconductor nanostructures convert red light into the twisted blue light in tiny volumes, which may help develop chiral drugs January 14th, 2022

UT Southwestern develops nanotherapeutic to ward off liver cancer January 14th, 2022

The free-energy principle explains the brain January 14th, 2022

Discoveries

Towards high-performance organic optoelectronics with better crystallinity at semiconductor interface: Organic molecular interfaces with minimized structural mismatch and spontaneous electron transfer could open doors to high-efficiency optoelectronics January 14th, 2022

Bioengineered nanoparticles show promise for fibrinogen manufacture, says Journal of Pharmaceutical Analysis study: Scientists engineer a nanoparticle polymer that can selectively bind to fibrinogen in human plasma, presenting a pathway for improved drug development January 14th, 2022

UT Southwestern develops nanotherapeutic to ward off liver cancer January 14th, 2022

The free-energy principle explains the brain January 14th, 2022

Announcements

Nanostructures get complex with electron equivalents: Nanoparticles of two different sizes break away from symmetrical designs January 14th, 2022

New photonic effect could speed drug development: Twisted semiconductor nanostructures convert red light into the twisted blue light in tiny volumes, which may help develop chiral drugs January 14th, 2022

UT Southwestern develops nanotherapeutic to ward off liver cancer January 14th, 2022

The free-energy principle explains the brain January 14th, 2022

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers/Posters

Photon recycling – The key to high-efficiency perovskite solar cells January 14th, 2022

Tuning the bonds of paired quantum particles to create dissipationless flow: A tunable platform made from atomically thin materials may help researchers figure out how to create a robust quantum condensate that can flow without losing energy January 14th, 2022

Nanostructures get complex with electron equivalents: Nanoparticles of two different sizes break away from symmetrical designs January 14th, 2022

New photonic effect could speed drug development: Twisted semiconductor nanostructures convert red light into the twisted blue light in tiny volumes, which may help develop chiral drugs January 14th, 2022

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project