(34h) Modulating Charge Transport in Vapor-Deposited Organic Semiconductors

Control over mesoscopic length scales is of vital importance for the optimized performance of organic semiconducting films. Provided the glassy nature of many common organic semiconducting molecules and polymers, molecular simulation has been limited in its utility in assessing the morphological and optoelectronic properties of these materials. In this work, we use a simulated vapor deposition protocol to deposit films of organic semiconductors at an atomistic level of detail. We begin with a minimal model for organic semiconductors and progress to realistic glassy OLED materials. By controlling the details of the deposition procedure (substrate temperature, deposition rate, etc), we demonstrate increased thermal stabilities and the ability to control molecular orientation in films of these “stable glasses”. Moreover, we incorporate a quantum-chemical analysis of charge transport descriptors as a function of film morphology by tuning film deposition parameters. These results suggest a novel simulation strategy capable of controlling the morphology-dependent electronic properties of organic semiconducting glasses prior to experimental deposition, which could have considerable potential for organic electronics materials design.