The role of the electrode configuration on the electrical properties of small-molecule semiconductor thin-films

Author(s)

Merces, Leandro ; de Oliveira, Rafael Furlan ; Gomes, Henrique Leonel ; Bof Bufon, Carlos Cesar

• Document type: Journal article
• Source: ORGANIC ELECTRONICS; v. 49, p. 107-113, OCT 2017.
• Web of Science Citations: 7

Abstract

This paper presents a systematic analysis of the electrode configuration influence on the electrical properties of organic semiconductor (OSC) thin-film devices. We have fabricated and electrically characterized a set of planar two-terminal devices. The differences in I-V characteristics between the top and bottom contact structures are presented and analyzed. Top-contact configurations have a linear current vs. electric field behavior, while the bottom-electrode devices display a transition from ohmic to spacecharge-limited conduction regime. The transition is temperature-and thickness-dependent. Finite-element calculations show that when the OSC film is connected using top electrodes, the current flows through the OSC bulk region. On the other hand, the bottom-electrode configuration allows most of the current to flow near the OSC/substrate interface. The current probes interfacial states resulting in a space-charge conduction regime. The results shed some light on the so-called ``contact effects{''} commonly observed in organic thin-film transistors. The findings presented here have implications for both the understanding of the charge transport in OSC films and the design of organic semiconductor devices. (C) 2017 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 14/25979-2 - Fabrication and characterization of devices and systems based on hybrid nanomembranes
• Grantee: Carlos César Bof Bufon
• Support Opportunities: Research Grants - Young Investigators Grants