中村 一希

電荷輸送特性の解析にはTime-of-flight (TOF) 過渡光電流測定が一般的に用いられている．しかし，TOF法では高電圧の印加や紫外光レーザーなどのパルス光の照射を行うため，素子へのダメージが問題となる場合がある．また，有機EL (OLED : Organic Light-emitting Diode) などに用いられる1μm以下の薄膜の測定が困難であるといった欠点がある．インピーダンス分光法による移動度解析では，直流電圧と微小な交流電圧を素子に印加し，重畳した交流電圧に対する素子の応答からキャリア移動度の解析を行う．この手法は，レーザー光の照射や高い電圧の印加の必要が無いため素子へのダメージを軽減でき，膜厚1μmを切る有機EL素子などでも積層膜そのままでの測定ができるといった利点がある．本研究では，トリフェニルアミン誘導体薄膜の電荷輸送特性の解析を，インピーダンス分光 (IS：Impedance Spectroscopy) 法を用いて数百nmから数μmの膜厚の膜に対して行い，TOF法による測定結果との比較を行った．その結果，IS法による解析においても従来のTOF法と同様にプールフレンケル型の電界強度依存性が明確に観測され，その移動度は10<sup>-6</sup>cm<sup>2</sup>/Vs程度の値を示した．また，IS法により算出された移動度は，TOF法によって求めた結果と良く一致した．さらに，移動度の電場および温度依存性からdisorder理論を用いて電荷輸送パラメータの解析も可能であることが分かった．

© 2014 . Society for Information Display. All rights reserved. Multi-functional composite films showing thermoresponsive switching of its absorption and emission were demonstrated by using thermochromic leuco dyes, developer and luminescent molecules. The composite films enabled control of the coloration and emission by thermal stimuli, resulting in RGB multicolor dual mode representation.

© 2014 . Society for Information Display. All rights reserved. Electrochromism (EC) is known as electrochemical reaction exhibiting coloration, and is applicable to a new imaging device. In this paper, we report EC molecule-modified electrode using phthalate derivatives. The EC molecule-modified electrode showed vivid magenta color by reduction reaction, better EC properties than solution based EC cell.

© 2013 ITE and SID. Emission color tuning of electrochemiluminescence (ECL) cell was demonstrated. This color tuning was conducted with modulation of the voltage or the frequency of AC voltage applied to a single ECL cell containing two luminescent molecules. Such ECL device is introduced as a unique and novel light-emission device has high productivity.

© 2013 ITE and SID. Multi-functional composite films showing thermoresponsive absorption and emission was demonstrated by using thermochromic leuco dyes, developer and luminescent molecules. The composite films enabled control of the coloration and emission by thermal stimuli, resulting in multicolor dual mode representation.

© 2013 ITE and SID. Novel multicolor electrochromic (EC) device based on electrochemical silver deposition mechanism was successfully demonstrated. The novel EC device achieved reversible change of primary colors - magenta, cyan, yellow, and black (CMYK) - in a single cell by using electrochemical method which controlled the size of deposited Ag nanoparticles.

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 reflectiveemissive dual-mode display cell. ©2013; Society for Imaging Science and Technology.

A multifunctional composite film that exhibited thermoresponsive absorption and emission was fabricated using a thermochromie leuco dye, its developer, and a luminescent Europium(III) complex. The emissions from and coloration of this composite film could be reversibly changed and maintained via the thermochromie reaction taking placing within the leuco dyedeveloper system. The coloration and decoloration of the composite film were caused by thermoresponsive control of the nanoscale aggregation of structures of the leuco dye and its developer, whose molecular structure consisted of a long alkyl chain. The control of the phenomenon ofphotoluminescence could also be achieved via thermochromism, which was induced by intermolecular energy transfers from the Eu(III) ions in the excited states to the leuco dye. ©2013; Society for Imaging Science and Technology.

The bio-organic thin film transistor (BiOTFT) with the DNA and DNA-surfactant complex as a dielectric layer shows memory function. In order to investigate the effect of surfactant structure on the OTFT memory device performance, different kinds of surfactant were introduced. Cetyltrimethylammonium chloride (CTMA), Lauroylcholine chloride (Lau) or Octadecyltrimethylammonium chloride (OTMA) as the cationic surfactant was mixed with DNA to prepare the DNA complex through the electrostatic interaction. In addition, the different molecular weight DNA also has been studied to analyze the effect of DNA chain length on the performance of the physical property. Many kinds of methods including UV-vis, Circular dichiroism (CD) and I-V characteristic have been applied to analyze the property of DNA complex. In conclusion, all of DNA complex with CTMA, OTMA and Lau were revealed to work as the bio-organic thin film transistor memory, and the device fabricated by Lau has the highest ON current and showed better device performance. © 2013 SPIE.