Influence of Molecular Shape on the Thermal Stability and Molecular Orientation of Vapor-Deposited Organic Semiconductors

Dataset · Tue Jul 25 00:00:00 EDT 2017

DOI:https://doi.org/10.11578/1372474· OSTI ID:1372474

Walters, Diane M  ^[1]; Antony, Lucas  ^[2]; de Pablo, Juan  ^[2]; Ediger, Mark  ^[1]

---

1. University of Wisconsin-Madison
2. University of Chicago

High thermal stability and anisotropic molecular orientation enhance the performance of vapor-deposited organic semiconductors, but controlling these properties is a challenge in amorphous materials. To understand the influence of molecular shape on these properties, vapor-deposited glasses of three disk-shaped molecules were prepared. For all three systems, enhanced thermal stability is observed for glasses prepared over a wide range of substrate temperatures and anisotropic molecular orientation is observed at lower substrate temperatures. For two of the disk-shaped molecules, atomistic simulations of thin films were also performed and anisotropic molecular orientation was observed at the equilibrium liquid surface. We find that the structure and thermal stability of these vapor-deposited glasses results from high surface mobility and partial equilibration toward the structure of the equilibrium liquid surface during the deposition process. For the three molecules studied, molecular shape is a dominant factor in determining the anisotropy of vapor-deposited glasses.

• Research Organization: University of Wisconsin-Madison University of Chicago
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• DOE Contract Number: SC0002161
• OSTI ID: 1372474
• Availability: University of Wisconsin-Madison
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
thermal stability
anisotropy
molecular orientation
thin film
organic semiconductor
vapor deposition