Shinichiro Tamura

24.4L: Late-News Paper: A 13.0-inch AM-OLED Display with Top Emitting Structure and Adaptive Current Mode Programmed Pixel Circuit (TAC)

A device structure and a driving method were developed to design large-scale active matrix organic light-emitting diode (AM-OLED) display with good gray scale uniformity and high aperture ratio. With these technologies, we developed a full color 13.0-inch SVGA AM-OLED display, the largest OLED display ever reported to date. These technologies will open up the OLED applications to larger size displays such as desktop monitors and TVs.

29.5L: Late‐News Paper: Advanced AM‐OLED Display Based on White Emitter with Microcavity Structure

We developed an AM-OLED display having saturated RGB, high efficiency and good contrast ratio. These properties, which outperform those of a conventional White OLED and color filter (WOLED+CF) system, were achieved with a unique combination of white emitter, microcavity structure and color filter array (WOLED+MC+CF).

Photochemical hole burning of tetraphenylporphine derivatives

The substituent effect on photochemical hole burning (PHB) for tetraphenylporphine was studied and the PHB efficiency was related to the electron donating and/or withdrawing properties of the substituents of the phenyl ring. The Hammett‐sigma constants of the substituents were related to the efficiency of the photochemical hole burning reaction. Compounds with a low Hammett‐sigma constant such as tetra‐(4‐methoxyphenyl)porphine had a higher PHB reaction efficiency than derivatives with a higher value such as tetraphenylporphine. We have also demonstrated multiple photochemical hole burning using this high efficiency compound tetra‐(4‐methoxyphenyl)porphine as a guest material.

Functional organic ultra-thin films for device applications

Topics in our recent research activities on lubrication of magnetic tape media, non-linear waveguide structures and epitaxial growth of organic molecules are reviewed from the practical point of view regarding organic ultra-films. Throughout these topics, the development of new functional organic ultra-thin films is an essential research theme for future electronic devices.

Photon-gated photochemical hole burning using zinc tetraphenylporphine and various electron acceptors

Abstract We have studied the photon-gated photochemical hole burning (PHB) which occurs due to an electron transfer reaction between the higher excited state of zinc tetraphenylporphine and a series of electron acceptors with various reduction potentials. The reaction activity of the PHB is dependent on the free energy change of the reaction and PHB was not observed in the highly exothermic region.

Electron transfer reaction from zinc(II)tetraphenylporphine to dichloromethane

The photo-induced electron transfer reaction from zinc tetraphenylporphine to dichloromethane on excitation of the Soret band at 425 nm was found to produce an oxophlorin derivative.

High performance OLED panels for Sony CLIE PDA: development of red emitter and super top emission structure

Sony has commercialized a full-color OLED comprising a new red emissive material, which provides high performance and long operation lifetime. We have carried out systematic research and developed a promising material that has excellent properties for practical applications. This compound shows an absorption peak and a luminescence peak at 483 nm and 644 nm, respectively. The molar absorption coefficient is large (ε = 38,100 M-1cm-1 in 1,4-dioxane) and the fluorescence quantum yield is also very high (QYf =0.82 in 1,4-dioxane). The glass transition temperature is as high as 135 °C. This compound offers thermally stable amorphous state in vacuum coating and is emissive even in single component films. We incorporated the new styryl compound in Sonys proprietary Super Top Emission technology and achieved outstanding brightness and wide color gamut comparable to the NTSC standard. The Super Top Emission consists of a top emitting device structure and color filters, which realize sufficient brightness and pure color at the same time without impairing the wide viewing angles. We obtained suitable device performance for practical use by tuning the layered structures. The emitting color is adjusted by optimizing the doping concentration of the styryl compound in the emitting layer and each thickness of the organic layers. We achieved the chromaticity (0.65, 0.35) in the CIE 1931 standard colorimetric system. The device operation lifetime exceeds 64,000 hours at the initial luminance 500 cd/m2. We would also like to discuss the advantages over the conventional red emissive materials.

Photon-gated photochemical hole burning using a zinc tetraphenylporphine derivative

Abstract We have demonstrated photochemical hole burning (PHB) using zinc tetrakis (bromoethoxycarbonylphenyl) porphine (ZnTBEP), a one-molecule system consisting of both electron donor and acceptor moieties. A spectral hole was observed when the sample was irradiated using a gating light in addition to the wavelength-selective light. In this system, we found that photon-gated photochemical holes were produced due to an electron transfer reaction from a higher triplet state. The introduction of electron acceptor moieties to the tetraphenylporphine moiety increases the local concentration of electron acceptors and thus enhances the electron transfer reaction from the higher triple state to the electron acceptors.

Optical Recording Materials.

コンパクトディスク,レーザーディスクをはじめとして,CDROM,ミニディスク等光メモリーは広く私達の生活に浸透している. 光メモリーはさらに高速化・高密度化の方向にあり,これに対応して超解像,短波長化技術あるいは材料の開発研究が盛んに行われている.これらの研究開発の現状および今後の展望について述べる.