Low driving voltage by novel light scattering mechanism in polymer composite liquid crystal device

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K04257
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 21060:Electron device and electronic equipment-related
• Research Institution: Akita University
• Principal Investigator: Yamaguchi Rumiko 秋田大学, 理工学研究科, 教授 (30170799)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: 高分子複合液晶 / 反応性メソゲン / 光散乱 / 低電圧駆動 / リバースモード / スマートウインドウ

Outline of Final Research Achievements

Driving voltage of a reverse mode liquid crystal devices in which an anisotropic polymer with a reactive mesogen group of about 3 to 10% is dispersed in the liquid crystal was successfully reduced without reducing the light scattering intensity. A "light scattering mechanism between the liquid crystal domains" was introduced in addition to the conventional "light scattering due to the difference in refractive index between the polymer and the liquid crystal". A simulation model incorporating a new light scattering mechanism was also constructed. Applied voltage of 5 V made it possible to electrically switch from the transparent state to the light scattering state in the liquid crystal devices.

Free Research Field

光デバイス

Academic Significance and Societal Importance of the Research Achievements

大小の液晶ドメインの再配向電圧の違いに着目し，“液晶ドメイン間での光散乱機構”を導入することで，光散乱強度を損なうことなく，駆動電圧の低減に成功した。従来の“高分子―液晶間の屈折率差による光散乱”機構と比較し，新規な光散乱機構の導入は駆動電圧を約半分にまで低減できることを，数値解析的に明らかにすることができた。リバースモード液晶素子は，スマートウインドウとして期待されているが，光散乱状態をプロジェクタースクリーンとして用いることで，透明ディスプレイにも応用可能である。