scholarly journals Efficient Interfacial Upconversion Enabling Bright Emission at an Extremely Low Driving Voltage in Organic Light‐Emitting Diodes

2022 ◽  
pp. 2101710
Author(s):  
Seiichiro Izawa ◽  
Masahiro Morimoto ◽  
Shigeki Naka ◽  
Masahiro Hiramoto
Keyword(s):  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Driving Voltage ◽  
Light Emitting ◽  
Organic Light ◽  
Bright Emission

scholarly journals Efficient Interfacial Upconversion Enabling Bright Emission with Extremely Low Driving Voltage in Organic Light-Emitting Diodes

2021 ◽  
Author(s):  
Seiichiro Izawa ◽  
Masahiro Morimoto ◽  
Shigeki Naka ◽  
Masahiro Hiramoto
Keyword(s):  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Operating Voltage ◽  
Driving Voltage ◽  
Light Emitting ◽  
Organic Light ◽  
Order Of Magnitude ◽  
Donor Acceptor ◽  
A Charge ◽  
Bright Emission

Reducing operating voltage is the remaining frontier for organic light-emitting diodes (OLEDs) because their quantum efficiency (QE) of electroluminescence has been already maximized. Herein, we report an efficient OLED in which a blight emission equivalent to a luminance of a display is achieved by only a 1.5 V battery. The OLED is based on upconversion (UC) emission utilizing triplet-triplet annihilation occurring near donor/acceptor (D/A) interface. We found that a character of a charge transfer state that is key intermediate for the UC emission could be controlled by D/A interfacial interaction. As a result, parasitic loss processes for UC were greatly suppressed from over 90% to about 10%, and two order of magnitude higher QE than the previous UC-OLED was achieved. Our result demonstrated that the efficient UC could be realized by the management of the energy transfer steps at the D/A interface and utilizing UC emission can be one of the possible candidate for efficient OLED with extremely low driving voltage.

scholarly journals Efficient Interfacial Upconversion Enabling Bright Emission with Extremely Low Driving Voltage in Organic Light-Emitting Diodes

2021 ◽  
Author(s):  
Seiichiro Izawa ◽  
Masahiro Morimoto ◽  
Shigeki Naka ◽  
Masahiro Hiramoto
Keyword(s):  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Operating Voltage ◽  
Driving Voltage ◽  
Light Emitting ◽  
Organic Light ◽  
Order Of Magnitude ◽  
Donor Acceptor ◽  
A Charge ◽  
Bright Emission

Reducing operating voltage is the remaining frontier for organic light-emitting diodes (OLEDs) because their quantum efficiency (QE) of electroluminescence has been already maximized. Herein, we report an efficient OLED in which a blight emission equivalent to a luminance of a display is achieved by only a 1.5 V battery. The OLED is based on upconversion (UC) emission utilizing triplet-triplet annihilation occurring near donor/acceptor (D/A) interface. We found that a character of a charge transfer state that is key intermediate for the UC emission could be controlled by D/A interfacial interaction. As a result, parasitic loss processes for UC were greatly suppressed from over 90% to about 10%, and two order of magnitude higher QE than the previous UC-OLED was achieved. Our result demonstrated that the efficient UC could be realized by the management of the energy transfer steps at the D/A interface and utilizing UC emission can be one of the possible candidate for efficient OLED with extremely low driving voltage.

Low driving voltage and high stability organic light-emitting diodes with rhenium oxide-doped hole transporting layer

2007 ◽  
Vol 91 (1) ◽  
pp. 011113 ◽  
Author(s):  
Dong-Seok Leem ◽  
Hyung-Dol Park ◽  
Jae-Wook Kang ◽  
Jae-Hyun Lee ◽  
Ji Whan Kim ◽  
...  
Keyword(s):  
High Stability ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Driving Voltage ◽  
Rhenium Oxide ◽  
Light Emitting ◽  
Organic Light ◽  
Hole Transporting

scholarly journals Realization of high-efficiency fluorescent organic light-emitting diodes with low driving voltage

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Amin Salehi ◽  
Chen Dong ◽  
Dong-Hun Shin ◽  
Liping Zhu ◽  
Christopher Papa ◽  
...  
Keyword(s):  
High Efficiency ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Driving Voltage ◽  
Light Emitting ◽  
Organic Light

scholarly journals Flexible organic light-emitting diodes for antimicrobial photodynamic therapy

2019 ◽  
Vol 3 (1) ◽  
Author(s):  
Cheng Lian ◽  
Marta Piksa ◽  
Kou Yoshida ◽  
Saydulla Persheyev ◽  
Krzysztof J. Pawlik ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Bacterial Infections ◽  
Light Emitting Diodes ◽  
High Irradiance ◽  
Organic Light Emitting Diodes ◽  
Light Sources ◽  
Driving Voltage ◽  
Light Emitting ◽  
Organic Light ◽  
Operational Lifetime

Abstract Bacterial infection and the growth of antibiotic resistance is a serious problem that leads to patient suffering, death and increased costs of healthcare. To address this problem, we propose using flexible organic light-emitting diodes (OLEDs) as light sources for photodynamic therapy (PDT) to kill bacteria. PDT involves the use of light and a photosensitizer to generate reactive oxygen species that kill neighbouring cells. We have developed flexible top-emitting OLEDs with the ability to tune the emission peak from 669 to 737 nm to match the photosensitizer, together with high irradiance, low driving voltage, long operational lifetime and adequate shelf-life. These features enable OLEDs to be the ideal candidate for ambulatory PDT light sources. A detailed study of OLED–PDT for killing Staphylococcus aureus was performed. The results show that our OLEDs in combination with the photosensitizer methylene blue, can kill more than 99% of bacteria. This indicates a huge potential for using OLEDs to treat bacterial infections.

Low-driving-voltage sky-blue phosphorescent organic light-emitting diodes with bicarbazole-bipyridine bipolar host materials

2021 ◽  
Author(s):  
Deli Li ◽  
Di Liu ◽  
Jiuyan Li ◽  
Ruizhi Dong ◽  
Botao Liu ◽  
...  
Keyword(s):  
High Efficiency ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Driving Voltage ◽  
Light Emitting ◽  
Turn On ◽  
Organic Light ◽  
Host Materials ◽  
Blue Phosphorescent

Two bipolar host containing bipyridine and bicarbazole exhibited rapid and balanced charge transportation, which resulting the extremely low turn-on voltages of 2.3 and 2.4 V, respectively, and the high efficiency of 23.7% and 52.6 lm W−1.

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