中村 一希

The photophysical properties of the DNA-CTMA/Eu(tta)3(H 2O)2 were investigated in order to apply them for novel photonic materials. From absorption and CD measurements, the intercalation of Eu(tta)3(H2O)2 into DNA-CTMA backbones was indicated. Furthermore, the emission properties of the DNA-CTMA/Eu(tta) 3(H2O)2 were superior to that of PMMA/Eu(tta)3(H2O)2 films. We expect achievements of our research help development of organic electronic device used biomaterials as typified by DNA-hybrid materials. © 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).

Electrochemiluminescence (ECL) is known as electrochemical reaction exhibiting emission, and is applicable to new imaging device. We studied the effects of TiO2 nanoparticles(Rutile & Anatase) on electrochemiluminescence of Ru(bpy)3(PF6)2. The luminescence of ECL cell with TiO2 (rutile) is 5 times higher than ECL cell without TiO2. The luminescence of cell with TiO2 (rutile & anatase) are durable compare to cell without TiO2.

Novel electrochromic (EC) cell based on electrochemical silver deposition mechanism was successfully demonstrated. The novel EC cell consisting of flat ITO electrode and ITO particle-modified electrode enabled selective three imaging states of clear transparent, silver-mirror and black color in single cell by changing bias polarity.

We are studying novel dual-mode display (DMD) driven by electrochemical reaction. Our DMD cell shows electrochromic (EC) properties as reflective mode and electrochemiluminescent (ECL) properties as emissive mode. In this paper, we reported the effect of structure and materials on characteristics of reflective-emissive dual-mode display cell.

We constructed novel display device with dual emissive and reflective display mode. The device consisted of luminescent lanthanide(III) complex Eu(hfa)3(TPPO)2 (photoluminescence material) and an diheptyl viologen (electrochromic material). In order to improve the response time of the dual-mode cell and decrease the driving voltage for dual-mode representation, we introduced prussian blue (PB) modified electrode as an electrochromical counter redox material.

Photophysical investigations of novel dual mode displaying material were precisely carried out. The material was composed of luminescent lanthanide complex and electrochromic molecule of diheptyl vilogen. As the result, the switching between emissive mode and reflective mode was achieved by intermolecular energy transfer from lanthanide complex to diheptyl viologen.

An AC bias-driven electrochemiluminescent (ECL) cell was fabricated as a novel light-emitting cell, and advantages of the AC-ECL such as electrochemical and emission properties were studied. The cell can be fabricated very simply. The emission turn-on response time and emission intensity were dramatically improved by introducing the AC method.

Particles of externally-additive-charge-control-agent (EA-CCA) were prepared by means of coacervation process and their effects on toner charge were investigated. EA-CCA particles comprised with metal oxide core particles of 110nm diameter and CCA molecules adhered on the core surface. Four kinds of negative charge control agent (CCA), which were boron complex (N-F), zinc complex (N-2), iron complex (N-3) and styrene-acrylate copolymer with sulfonic acid (N-4), were applied to EA-CCA, respectively. Tribo-charge of the mixture of model toner and EA-CCA was measured in the CCA concentration range up to 1,000ppm against model toner by using blow off method. In both N-2 and N-4 added systems, tribo-charges were increased with increasing CCA concentration up to 1000ppm, in the range of these experiments. In other two CCA added systems, maximum region appeared in tribo-charge around 50ppm of CCA concentration. Relationships between tribo-charge and CCA concentration in all CCA show linear in smaller CCA concentration range, less than 20ppm. The former two kinds of CCA added system have slope value of one fifth smaller than latter two kinds of CCA system. It means that efficiency of CCA molecules was different among CCAs on tribo-charge. The difference considered to be dissociation energy and/or interaction between each CCA molecule on the core surface. ©2011 Society for Imaging Science and Technology.

We demonstrated green to red color-tunable OLED based on DNA/PAn/Ru(bpy)32+ complex (hole transport layer) and tris(8-hydroxyquinolinato)aluminium (Alq3: electron transport layer). The emission color of the OLED was controlled by applied voltage. At low applied voltage, the green emission dominated by Alq3 was observed. The emission color was changed from green, yellow to red with a strong contribution of red emission of Ru(bpy)32+ as voltage increased. This multi color emission phenomenon would be attributed to the shift of the carrier recombination zone depending on applied voltage. © 2010 SPIE.

We successfully demonstrated novel imaging cell with reflective and emissive mode driven by electrochromic and electrochemiluminescence reactions. This dual-mode cell has simple structure and driving feature which reflective and emissive mode can be controlled by selecting DC and AC driving method, respectively. © 2010 ITE and SID.

A novel display device with dual emissive and reflective display mode is demonstrated. The device consists of luminescent lanthanide(III) complexes (photo- luminescence materials) and an electrochromic material. The device functions as an electrochromic device when bias voltages are applied and as a light-emitting device if excitation lights are irradiated. © 2010 ITE and SID.

DNA/functional molecules such as (Ru(bpy)32+ complex, conducting polymer etc.) complex was prepared to study molecular structure and I-V characteristics towards DNA molecular wire. For example, Ru(bpy) 32+ was associated with duplex of DNA by not only electrostatic interaction but also intercalation in the aqueous solution. Singlemolecular structure of DNA/Ru(bpy)32+ complex was analyzed with AFM. We found a network structure of DNA/Ru(bpy)32+ complex on the mica substrate, which is similar to native DNA. The height of DNA/Ru(bpy)32+ complex on the mica substrate was ranging from 0.8 to 1.6 nm, which was higher than the naked DNA (0.5-1.0 nm). This indicates that single-molecular DNA/Ru(bpy)32+ complex also connects to each other to form network structure on a mica substrate. In order to stretch DNA complex between electrodes, we employed high frequency and high electric field stretching method proposed by Washizu et al. We stretched and immobilized DNA single molecules between a pair of electrodes and its structures were analyzed with AFM technique. The I-V characteristics of DNA single molecules between electrodes were improved by the association of functional molecules with DNA. The molecular structure and I-V characteristics of DNA complex were discussed. © 2009 SPIE.

配位子にホスフィンオキサイドを有する新規Eu(III)錯体を合成し、レーザー発振媒体としての評価・検討を行った。X線結晶構造解析により、Eu(III)錯体は、反転中心を持たない非対称構造を取っていることが示された。この非対称構造により生じる発光のスペクトルの半値幅は、2.1nmほどの非常に狭いものとなり、誘導放出断面積の値は、1.80×10^<-20>cm^<-2>と大きいものとなった。Eu(III)錯体を含んだポリマー薄膜を、パルスレーザー励起を行ったところ、基板端面からの発光は一次の指数関数に従い減衰した(τ=650μs)が、励起光強度を増加していくと、短い寿命成分(τ=83μs)が生じ、その割合が増加していた。この短い寿命成分は、増幅自然放出光によるものであり、しきい値は0.05mJ以下であった。