We report that organic electroluminescence devices with a distyrylarylene (DSA) emitting layer including a new dopant realized highly efficient and bright emission in blue region. This dopant was amino-substituted DSA. The luminous efficiency was obtained to be 1.5 lm/W. The external quantum efficiency was estimated to be 2.4%, which is one of the highest efficiencies ever reported in blue emitting organic EL devices.

Organic light-emitting field-effect transistors, based on a p-bis[(p-styryl)styryl] benzene (P5V4) single crystal, that possess high mobilities of over 0.1 cm2/V s for both electrons and holes were fabricated. For a small charge injection barrier and successive formation of high exciton density in the carrier recombination zone, the hole accumulation threshold voltage was significantly reduced by interfacial hole doping based on electron transfer from P5V4 molecules to a molybdenum oxide layer. The threshold voltage for hole accumulation was drastically decreased from −80±3 to 2±3 V, leading to dual charge injection and accumulation of a very high current density of J>100 A cm−2 with intense edge electroluminescence.

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The effect of dye‐doping in ambipolar light‐emitting organic field‐effect transistors (LE‐OFETs) is investigated from the standpoint of the carrier mobilities and the electroluminescence (EL) characteristics under ambipolar operation. Dye‐doping of organic crystals permits not only tuning of the emission color but also significantly increases the efficiency of ambipolar LE‐OFETs. A rather high external EL quantum efficiency (∼0.64%) of one order of magnitude higher than that of a pure p‐distyrylbenzene (P3V2) single crystal is obtained by tetracene doping. The doping of tetracene molecules into a host P3V2 crystal has almost no effect on the electron mobility and the dominant carrier recombination process in the tetracene‐doped P3V2 crystal involves direct carrier recombination on the tetracene molecules.

The interface reactions of the B2O3‐normalSi system were studied by infrared spectroscopy, electron and x‐ray diffraction, etc.The compound, which was produced at the B2O3‐normalSi interface in the temperature range of 900°–1200°C closely resembled SiB4 or SiB6 in the diffraction measurements. The growth rate of silicon oxide, produced in the interface in an oxygen atmosphere, was several times as fast as that in a nitrogen atmosphere. These growth rates are much faster than the ordinary growth rate of silicon oxide in a dry oxygen atmosphere. From these data, the rate constants of growth of silicon oxide were estimated, assuming the relationship of the parabolic oxidation.Comparing these results with the doping amount of boron in silicon, it was confirmed that the rate‐determining step of the transfer of boron into silicon was classified by whether the above Si‐B compound was present or not.