Interaction of Organic Surfaces with Active Species in the High-Vacuum Environment

TL;DR

This study investigates how organic surfaces in high-vacuum environments generate electronic defects due to interactions with free radicals produced by hydrocarbon cracking, affecting device performance.

Contribution

It reveals the mechanism of defect generation on organic surfaces caused by free radicals in high-vacuum conditions, aiding device fabrication optimization.

Findings

Electronic defects form on organic surfaces in high vacuum.

Source-drain current decreases rapidly upon exposure to free radicals.

Defect formation linked to hydrocarbon cracking on hot filaments.

Abstract

Using single-crystal organic field-effect transistors with the conduction channel exposed to environmental agents we have observed generation of electronic defects at the organic surface in the high-vacuum environment. Rapid decrease of the source-drain current of an operating device is observed upon exposure of the channel to the species generated by high-vacuum gauges. We attribute this effect to interaction of the organic surface with electrically neutral free radicals produced in the process of hydrocarbon cracking on hot filaments with a relatively low activation energy Ea ~ 2.5 eV (240 kJ/mol). The reported results might be important for optimizing the high-vacuum processes of fabrication and characterization of a wide range of organic and molecular electronic devices.