Light-emitting field-effect transistors combining organic and metal oxide layers with partitioned heterogeneous source and drain electrodes

Abstract

We fabricated organic light-emitting field-effect transistors (OLEFETs) characterized by partitioned heterogeneous source and drain contacts along with an aluminum-doped zinc oxide (AZO) layer inserted between an organic layer and a gate insulator. We elaborated such contacts so that each contact was made of a metal(s) suitable for injecting either electrons or holes. We fabricated the devices by choosing two of three kinds of metals (Au, Al, and MgAg) and one of three organic semiconductor materials. In the devices with the Au source and MgAg drain contacts, we observed drain currents at both positive and negative drain voltages. Those currents were predominant at negative drain voltages in the devices with Al drain contacts. The most intense current-injected emissions arose from the vicinity of the electron injection contact edges near channels on the AZO layers. Taking into account the energy level consideration of the materials and the effect of the partitioned contacts, we discussed these electrical and emission properties.