Over What Length Scale Does an Inorganic Substrate Perturb the Structure of a Glassy Organic Semiconductor

TitleOver What Length Scale Does an Inorganic Substrate Perturb the Structure of a Glassy Organic Semiconductor
Publication TypeJournal Article
Year of Publication2020
AuthorsBagchi, Kushal, Chuting Deng, Camille Bishop, Yuhui Li, Nicholas E. Jackson, Lian Yu, M. F. Toney, J. J. de Pablo, and M. D. Ediger
JournalACS Applied Materials and Interfaces
Volume12
Start Page26717
Issue23
Pagination26717-26726
Date Published06/2020
Abstract

While the bulk structure of vapor-deposited glasses has been extensively studied, structure at buried interfaces has received little attention, despite being important for organic electronic applications. To learn about glass structure at buried interfaces, we study the structure of vapor-deposited glasses of the organic semiconductor DSA-Ph (1,4-di-[4-(N,N-diphenyl)amino]styrylbenzene) as a function of film thickness; the structure is probed with grazing incidence X-ray scattering. We deposit on silicon and gold substrates and span a film thickness range of 10–600 nm. Our experiments demonstrate that interfacial molecular packing in vapor-deposited glasses of DSA-Ph is more disordered compared to the bulk. At a deposition temperature near room temperature, we estimate ∼8 nm near the substrate can have modified molecular packing. Molecular dynamics simulations of a coarse-grained representation of DSA-Ph reveal a similar length scale. In both the simulations and the experiments, deposition temperature controls glass structure beyond this interfacial layer of a few nanometers.

URLhttps://pubs.acs.org/doi/10.1021/acsami.0c06428
DOI10.1021/acsami.0c06428