Ultrathin Films of Liquid Crystal Obtained via Organic Molecular Beam Deposition Method

The miniaturization of devices causes an increase in scientists’ interest in the possibility of creating and characterizing ultrathin layers of liquid crystals. Using organic molecular beam deposition (OMBD), organic thin layers are produced in ultrahigh vacuum by single molecule deposition on a cold substrate. In this article, we verify the possibility of creating thin films of liquid crystal below the glass transition temperature by the OMBD method. We also investigated the effect of various OMBD deposition parameters on the layer thickness and the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\alpha $ </tex-math></inline-formula>-relaxation dynamics of the compound under study. Some striking differences in relaxation dynamics related to glass-forming behavior are observed in ultrathin films compared to the bulk. We show that real time, in situ dielectric relaxation spectroscopy can be successfully applied to study the dynamic glass transition in geometric confinement, not only for simple glass-forming liquids but also for glass-forming liquid crystals using OMBD.