Large magnetoresistance at room-temperature in semiconducting polymer sandwich devices

TL;DR

This paper reports a significant room-temperature magnetoresistance effect in polyfluorene devices, with up to 10% change at 10mT, influenced by device parameters and related to hole current, offering potential for magnetic sensing applications.

Contribution

It demonstrates a large, room-temperature MR effect in polymer devices and explores its dependence on various device and material parameters, revealing new insights into organic magnetoresistance phenomena.

Findings

MR reaches up to 10% at 10mT at room temperature

MR effect is weakly temperature-dependent and independent of magnetic field direction

The effect is related to hole current in the devices

Abstract

We report on the discovery of a large, room temperature magnetoresistance (MR) effect in polyfluorene sandwich devices in weak magnetic fields. We characterize this effect and discuss its dependence on voltage, temperature, film thickness, electrode materials, and (unintentional) impurity concentration. We usually observed negative MR, but positive MR can also be achieved under high applied electric fields. The MR effect reaches up to 10% at fields of 10mT at room temperature. The effect shows only a weak temperature dependence and is independent of the sign and direction of the magnetic field. We find that the effect is related to the hole current in the devices.