Performances of Pentacene OFETs Deposited by Arbitrary Mounting Angle Vacuum Evaporator

Abstract

A vacuum evaporator is widely used for generating atomic/molecular beams for thin film deposition, and conventionally must be mounted to a vacuum chamber with an upwards angle from the horizontal. In this article, we report a novel kind of evaporator that can be mounted at an arbitrary angle for organic materials. The crucible of the evaporator here is designed to keep the loaded organic materials from falling. The morphology and electrical characteristics of pentacene thin film organic field effect transistors on trichloro(octadecyl)silane modified SiO2 are characterized and compared for commercial and arbitrary mounting angle evaporators. Pentacene films deposited from both evaporators exhibit similar morphology and domain size characterized by atomic force microscope, as well as similar mobility, threshold voltage, and on/off ratio. The results can be used to develop a new configuration for an organic vacuum deposition system, which allows the positioning of shadow masks directly on substrates and thus avoids deformation, enabling fabrication of organic electronics for high resolution over large areas.