Blue OLED Advancement Set to Transform Smartphone and Large Screen Displays

Display Technology Art Concept

Researchers from Tokyo Tech have innovated an OLED that emits blue light at a record low voltage of 1.47 V, potentially revolutionizing commercial smartphone and display technologies.

An upconversion organic light-emitting diode (OLED) based on a typical blue-fluorescence emitter achieves emission at an ultralow turn-on voltage of 1.47 V, as demonstrated by researchers from Tokyo Tech. Their technology circumvents the traditional high voltage requirement for blue OLEDs, leading to potential advancements in commercial smartphone and large-screen displays.

In this regard, Associate Professor Seiichiro Izawa from Tokyo Institute of Technology and Osaka University, collaborated with researchers from University of Toyama, Shizuoka University, and the Institute for Molecular Science has recently presented a novel OLED device with a remarkable ultralow turn-on voltage of 1.47 V for blue emission and a peak wavelength at 462 nm (2.68 eV) (as shown in Figure 1). Their work will be published today (September 20) in the journal Nature Communications.

Lighting Up a Blue Organic LED

Figure 1. Lighting up a blue organic LED with a single AA battery. Credit Associate Professor Izawa and team

New Frontier for Blue Organic Light-Emitting Diodes

Figure 2. An upconversion organic light-emitting diode (OLED) based on a typical blue-fluorescence emitter achieves emission at an ultralow turn-on voltage of 1.47 V, as demonstrated by researchers from Tokyo Tech. Their technology circumvents the traditional high voltage requirement for blue OLEDs, leading to potential advancements in commercial smartphone and large-screen displays. Credit: Associate Professor Seichiro Izawa

Subsequently, the energy of the CT state is selectively transferred to the low-energy first triplet excited states of the emitter, which results in blue light emission through the formation of a high-energy first singlet excited state by triplet-triplet annihilation (TTA). “As the energy of the CT state is much lower than the emitter’s bandgap energy, the UC mechanism with TTA significantly decreases the applied voltage required for exciting the emitter. As a result, this UC-OLED reaches a luminance of 100 cd/m2, equivalent to that of a commercial display, at just 1.97 V,” explains Dr. Izawa.

In effect, this study efficiently produces a novel OLED, with blue light emission at an ultralow turn-on voltage, using a typical fluorescent emitter widely utilized in commercial displays, thus marking a significant step toward meeting the commercial requirements for blue OLEDs. It emphasizes the importance of optimizing the design of the D/A interface for controlling excitonic processes and holds promise not only for OLEDs but also for organic photovoltaics and other organic electronic devices.

Reference: “Blue Organic Light-Emitting Diode with a Turn-on Voltage of 1.47 V” 20 September 2023, Nature Communications.
DOI: 10.1038/s41467-023-41208-7


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