Comprehensive molecular dynamics simulations to reproduce the whole processes of nucleation and growth of organic semiconductor thin films

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K05205
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 35030:Organic functional materials-related
• Research Institution: Tohoku University
• Principal Investigator: Ikeda Susumu 東北大学, 材料科学高等研究所, 准教授 (20401234)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 有機半導体 / 分子動力学シミュレーション / 薄膜 / 核生成 / 結晶成長

Outline of Final Research Achievements

This study aimed for comprehensive molecular dynamics (MD) simulations reproducing the whole processes of nucleation and growth of organic semiconductor thin films to understand the mechanism governing elementary processes indwelling in nucleation and growth. There is a universally observed but unsolved phenomenon in which rod-shaped molecules are aligned with standing manner on substrate surfaces. In this study, this phenomenon was especially focused on as the target of MD simulations. Such reorientation process of molecules from flat-lying to standing manners could be reproduced by MD simulations under the condition where a cluster comprising standing molecules was placed in the initial model together with flat-lying molecules and clusters. The result of this study opens up new prospects for reproducing the whole processes of nucleation and growth including the reorientation process by MD simulations.

Free Research Field

材料科学、有機半導体、薄膜成長

Academic Significance and Societal Importance of the Research Achievements

次世代の薄膜トランジスタ用材料として期待される有機半導体には、物質固有のキャリア移動度が無機半導体に比べ小さいという潜在的な問題があるが、薄膜化すると粒界や分子配列の乱れによって移動度は更に小さなものとなる。移動度最大の高品質薄膜を得るためには、核生成・薄膜成長のプロセスを完全に制御する必要があり、その基礎として、核生成・薄膜成長メカニズムを分子レベルで解明、理解することが必須となる。本研究では、有機半導体の核生成・薄膜成長プロセスを分子動力学シミュレーションによって包括的に明らかにし、有機エレクトロニクスによる社会貢献の基盤となる基礎的知見を提供する。