Blue electroluminescent diodes utilizing poly(alkylfluorene) have been demonstrated for the first time. A Schottky-type electroluminescent diode of poly(9,9-dihexylfluorene) is driven at ∼10 V and has a peak emission wavelength of 470 nm at room temperature.

A visible-light electroluminescent diode utilizing poly(3-alkylthiophene) has been demonstrated for the first time. The light emission intensity increases superlinearly with increasing injected current. Remarkable enhancement of electroluminescence intensity is obtained for a poly(3-alkylthiophene) diode with longer alkyl side chain length.

Three separate organic, fluorescent emitter molecules with emission spectra corresponding to either blue, orange, or yellow have been covalently attached to an inorganic polyhedral oligomeric silsesquioxane (POSS) core in several controllable combinations. We were able to functionalize POSS with eight of the same emitters or a combination of two different emitters (i.e., blue and orange or blue and yellow). After purification, monodisperse products of the desired ratio of emitters attached to POSS were obtained. Solution and thin-film photoluminescence spectra were measured and compared for both the free emitters and the functionalized POSS. All POSS emitter materials have shown an increase in thermal stability over their free emitter counterparts and were able to be spincoated from solution for the fabrication of OLED devices.

Direct fabrication of organic light-emitting diodes (OLEDs) and organic photodetectors (OPDs) on polymeric substrates, i.e., polymeric waveguide substrates to form flexile optical integrated devices is demonstrated. The OELD and OPD were fabricated by organic molecular beam deposition (OMBD) technique on a polymeric or a glass substrate, for comparison. The device fabricated on a polymeric substrate shows similar device characteristics to that on a glass substrate. Optical signals of faster than 100 MHz have been created by applying pulsed voltage directly to the OLED utilizing diamine derivative, or rubrene or porphine doped in 8-hydoxyquinolinum aluminum derivatives, as an emissive layer. Electrical signals are successively converted to optical signals for optical transmission of moving picture signals with OLED fabricated on a polymeric waveguide. OPDs utilizing phthalocyanines derivatives with superlattice structure provide increased pulse response with input optical signals, and the OPD with the cutoff frequency of more than 5 MHz has been realized. Index Terms-Optical integrated circuits, organic light-emitting device, organic photodetectors, polymeric waveguide. I. INTRODUCTION O RGANIC light-emitting diodes (OLEDs) [1] utilizing fluorescent dye or conducting polymer have attracted great interest because they have advantages for thin-film flat-panel display. An additional advantage is that they are simple for fabrication on various kinds of substrates, including polymeric substrates. Metal phthalocyanines are well-known materials which show good stability, photo activity, and with high mobility. Among them, fluorinated phthalocyanine shows high-electron mobility and will be suitable for photo-absorption and carrier generation layers of organic photodetectors (OPD) with combination with metal phthalocyanines. Forrest et al. reported high-speed OPD utilizing organic materials [2]. On the other hand, polymeric waveguide devices have attracted great attention with regard to their use for optical interconnection Manuscript

A color-variable light-emitting diode has been realized utilizing conducting polymer, poly(2,5-dioctyloxy-p-phenylene vinylene) (ROPPV-8), mixed with fluorescent dye, 8-hydroxyquinoline aluminum (Alq3). The electroluminescence of the diode changes from orange to greenish-yellow in color with increasing applied voltage. On the other hand, a light-emitting diode with the two-layer structure of ROPPV-8 and Alq3 shows only light emission from the ROPPV-8 layer. This difference is discussed in terms of the carrier injection process to Alq3.