Hirohiko Fukagawa

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Organic light-emitting diodes (OLEDs) have been intensively studied as a key technology for next-generation displays and lighting. The efficiency of OLEDs has improved markedly in the last 15 years by employing phosphorescent emitters. However, there are two main issues in the practical application of phosphorescent OLEDs (PHOLEDs): the relatively short(More)
There have been many reports on phosphorescent organic light-emitting diodes (PHOLEDs) because of their relatively high emission effi ciencies compared with those of conventional fl uorescent OLEDs. [ 1–3 ] In addition to their effi ciency, the driving voltage and operational stability are important factors in the application of PHOLEDs to displays and(More)
The hole–phonon coupling of a rubrene monolayer on graphite is measured by means of angle resolved ultraviolet photoelectron spectroscopy. Thus, the charge reorganization energy λ and the small polaron binding energy is determined, which allows insight into the nature of charge transport in condensed rubrene.
Organic light-emitting diodes are a key technology for next-generation information displays because of their low power consumption and potentially long operational lifetimes. Although devices with internal quantum efficiencies of approximately 100% have been achieved using phosphorescent or thermally activated delayed fluorescent emitters, a systematic(More)
Organic light-emitting diodes (OLEDs) are very attractive for full-color fl at-panel displays and lighting applications. OLED characteristics, such as device stability and the power effi ciency, must be improved for them to become practical. Low-powerconsumption OLEDs can be fabricated by i) improving the current effi ciency and ii) reducing the driving(More)
This paper describes our recent progress in the development of oxide thin-film transistors (TFTs) for use in flexible organic light-emitting diode (OLED) displays. The bending stability of oxide TFTs was investigated using In-Ga-Zn-O (IGZO) TFTs fabricated on a thin polyimide film. Back-channel-etched (BCE) TFTs on a plastic film using In-Sn-Zn-O (ITZO),(More)
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