Preparation of High-quality Vapor-deposited Crystalline Organic Thin Films through Crystallization from Their Liquid Crystal Phase

Abstract

High-quality crystalline organic thin films with large crystalline domain size were fabricated by vacuum deposition, followed by a post-annealing and cooling crystallization from their respective smectic A (SmA) liquid crystal precursor states. Crystallinity, surface smoothness and air exposure stability of ionic liquid crystalline thin films were much improved by this process, and the electric double layer action was for the first time observed at the SmA phase. Moreover, a seeded temperature gradient cooling process from the SmA phase was proposed and its capability was demonstrated in the fabrication of benzothienobenzothiophene derivative thin films, achieving their directional lateral crystal growth with high precision controllability.