[11a-M111-1~10] 12.1 Fabrications and Structure Controls

[11a-M111-6] Molecular Dynamics Simulations of Organic Semiconductor Thin Film Growth
– Stability of Nuclei Comprising Standing Molecules and Subsequent Growth –

〇Susumu Ikeda¹ (1.WPI-AIMR, Tohoku Univ.)

Keywords:organic semiconductor, molecular dynamics simulations, pentacene

In the previous JSAP meetings, I reported some results of molecular dynamics (MD) simulations reproducing the graphoepitaxial growth of organic semiconductors, sexithiophene and pentacene on grooved substrates. After that, I have been trying to simulate the processes of nucleation and growth of organic semiconductor thin films on flat substrate surfaces. Owing to the limitation of time and the number of molecules which can be treated within the limited capability of computation, it seems hard to reproduce the process in which rod-shaped molecules (e.g., pentacene) stand up spontaneously on flat surfaces by MD simulations though "standing-fashion" is universal in the actual thin films when the substrate temperature is relatively high. Therefore, I have changed the strategy and started another type of simulations. I prepared a cluster comprising standing pentacene molecules, as an initial condition, on a flat substrate surface and evaluated the stability of the cluster. It was found that clusters consisting of more than thirty standing molecules could exist stably on the flat surface and could grow by incorporating surrounding molecules.