Bipolar-Driven Large Magnetoresistance in Silicon

TL;DR

This paper reports the observation of large linear magnetoresistance in silicon at room temperature, driven by bipolar charge transport, offering a new mechanism distinct from inhomogeneity-based models.

Contribution

It introduces a novel bipolar-driven mechanism for large linear MR in homogeneous silicon, differing from previous inhomogeneity-based explanations.

Findings

Large linear MR observed at low magnetic fields in silicon.

MR is controlled by electron-to-hole density ratio modulation.

The mechanism differs from inhomogeneity-induced MR in unipolar devices.

Abstract

Large linear magnetoresistance (MR) in electron-injected p-type silicon at very low magnetic field is observed experimentally at room temperature. The large linear MR is induced in electron-dominated space-charge transport regime, where the magnetic field modulation of electron-to-hole density ratio controls the MR, as indicated by the magnetic field dependence of Hall coefficient in the silicon device. Contrary to the space-charge-induced MR effect in unipolar silicon device, where the large linear MR is inhomogeneity-induced, our results provide a different insight into the mechanism of large linear MR in non-magnetic semiconductors that is not based on the inhomogeneity model. This approach enables homogeneous semiconductors to exhibit large linear MR at low magnetic fields that until now has only been appearing in semiconductors with strong inhomogeneities.