Achieving Bright Organic Light Emitting Field Effect Transistors with Sustained Efficiency through Hybrid Contact Design

TL;DR

This paper introduces a hybrid contact design for organic light emitting field effect transistors that maintains high efficiency across a wide brightness range by balancing charge transport, promising advancements in organic electronic devices.

Contribution

The study presents a novel hybrid contact structure that stabilizes charge recombination and sustains high external quantum efficiency in OLEFETs at high brightness levels.

Findings

Achieves a sustained EQE of 0.23% over 3 orders of magnitude brightness.

Maintains high efficiency even with increased EQE to ~0.51%.

Demonstrates potential for high-brightness, efficient organic light-emitting devices.

Abstract

Organic light emitting field effect transistors (OLEFETs) with bilayer structures have been widely studied due to their potential to integrate high-mobility organic transistors and efficient organic light emitting diodes. However, these devices face a major challenge of imbalance charge transport leading to severe efficiency roll-off at high brightness. Here, we propose a solution to this challenge by introducing a transparent organic/inorganic hybrid contact with specially designed electronic structures. Our design aims to steadily accumulate the electrons injected to the emissive polymer, allowing the light emitting interface to effectively capture more holes even when hole current increases. Our numerical simulations show that the capture efficiency of these steady electrons will dominate charge recombination and lead to a sustained external quantum efficiency of 0.23% over 3 orders of magnitude of brightness (4 to 7700 cd/m2) and current density (1.2 to 2700 mA/cm2) from -4 to -100 V. The same enhancement is retained even after increasing EQE to ~0.51%. The high and tunable brightness with stable efficiency offered by hybrid-contact OLEFETs make them ideal light emitting devices for various applications. These devices have the potential to revolutionize the field of organic electronics by overcoming the fundamental challenge of imbalance charge transport.