Investigation of the magnetic field effects on the electron mobility in tri-(8-hydroxyquinoline)-aluminum based light-emitting devices

TL;DR

This study examines how magnetic fields influence electron mobility in aluminum-based light-emitting devices, revealing that magnetic effects primarily impact carrier recombination rather than mobility mechanisms.

Contribution

It provides experimental evidence that magnetic fields affect carrier recombination processes, challenging existing models like bipolaron and triplet-polaron interactions as primary explanations.

Findings

Magnetic fields alter electroluminescence pulse edges.

Bipolaron and triplet-polaron models are not dominant under tested conditions.

Magnetic effects influence carrier recombination processes.

Abstract

We investigated the mganetic field effects (MFEs) on electron mobility in tri-(8-hydroxyquinoline)-aluminum based light-emitting devices by transient-electroluminescence method upon application of various offset voltages. It is found the rising edges of EL pulses are well overlapped and the falling edges of EL pulses are separated for the magnetic field on and off when Voffset=0 V and Voffset>Vturnon of the devices. The results suggest the bipolaron model and the triplet-polaron interaction model related to the carriers mobilities are not the dominant mechanisms to explain the MFEs under our experimental conditions, and the magnetic field affects the carriers recombination process is confirmed.