Performance improvement of organic thin-film transistors using cardo polymer as the gate dielectric and application to a flexible display

2014 Fiscal Year Final Research Report

• Project/Area Number: 25820119
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Electronic materials/Electric materials
• Research Institution: Yamagata University
• Principal Investigator: OKU Shinya 山形大学, 理工学研究科, 助教 (80625525)
• Co-Investigator(Renkei-kenkyūsha): CHO Seung-Il 山形大学, 大学院理工学研究科, 助教 (10732464) ; MIZUKAMI Makoto 山形大学, 大学院理工学研究科, 准教授 (70625524) ; TOKITO Shizuo 山形大学, 大学院理工学研究科, 教授 (80197863) ; SAKANOUE Tomo 早稲田大学, 理工学術院, 准教授 (60615681)
• Research Collaborator: TATETSU Masahiro ; ABIKO Miho ; TAKANO Masaomi ; FUKUMATSU Noriyuki
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: 有機トランジスタ / カルド / ディスプレイ / 絶縁膜 / 有機EL / 高分子

Outline of Final Research Achievements

In this project, we investigated the performance characteristic of cardo polymer gate dielectric for organic thin-film transistors (OTFTs). The 400-nm-thick films of a spin-coated cardo polymer had very low surface roughness and excellent electrical insulating properties. The bottom-contact type, pentacene-based short channel OTFT showed excellent performance such as a hole mobility of 0.15 cm^2/Vs and large ON/OFF ratio of above 10^7. In addition, the fabricated OTFT demonstrated high stability against gate bias stress.
Moreover, we fabricated organic light-emitting diode (OLED) display driven by active matrix backplane based on solution-processed OTFTs using cardo polymer gate dielectric. It had 384 × 128 pixels at a resolution of 300 dpi, and successfully displayed images and videos.
These results demonstrate that our cardo polymer material is a good candidate for a physically and chemically robust dielectric material suitable for realizing various flexible electronics applications.

Free Research Field

有機トランジスタ