Okinawa Institute of Science and Technology School Corporation

Kyushu University

Ryota Kabe

Chihaya Adachi

Takashi Tachikawa

Kazuya Jinnai

Photostimulated luminescence, which allows energy or data to be stored and released using electromagnetic waves as both the input and output, has attracted considerable interest in the fields of biomedical and informatics technologies, but this phenomenon is mostly limited to solid inorganic materials. Here, we report photostimulated luminescence from purely organic blend films composed of electron donor, acceptor, and trap/emitter molecules. In the films, charges are accumulated as radical ions by ultraviolet light irradiation and then extracted by near infrared light irradiation to produce visible light. Films are capable of multiple cycles (>10 times) of organic photostimulated luminescence, which was still observable from films left in the dark at room temperature for one week after excitation, and emission color could be varied by changing the trap/emitter molecules. These findings will broadly impact existing applications and provide new prospects for innovative flexible devices.

Composition, organic photostimulated luminescent device, luminescent method and method for designing composition for photostimulated luminescence

An organic long-persistent luminescent composition containing a first organic compound, a second organic compound and a third organic compound and satisfying the following expression (1) is a long-persistent luminescent material that facilitates emission color control. E(A) represents a lowest excited singlet energy level of emission from the first organic compound and the second organic compound, E(B) represents a lowest excited singlet energy level of the third organic compound.()&#x2212;()&#x2264;0.15 eV&#x2003;&#x2003;(1)

Long-persistent luminescent composition, long-persistent luminescent device and wavelength control method

The invention discloses a long persistent luminescence emitter which has an electron-donating molecule that is stable in the radical cation state and an electron-accepting molecule that is stable in the radical anion state and from which luminescence is observed at 10 K after photo-irradiation of the long persistent luminescence emitter stops. According to the disclosed invention, persistent luminescence can be exhibited for a long time with only organic compounds without the use of any rare-earth elements.

Growing community of inventors

Fukuoka, Japan

Ryota Kabe