Space-charge-effect-induced large magnetoresistance in silicon

Abstract

We report that silicon shows large positive magnetoresistance (MR) between 0 and 3 T more than 1,000 per cent at 300 K and 3,000 per cent at 25 K. The experiment on lightly doped silicon reveals that when the carrier density decreases below 1013 cm-3 the MR becomes pronounced due to the space-charge effect. We propose that the quasi-neutrality breaking of the space-charge effect can introduce electric field inhomogeneity, similar to the situation in other semiconductors where the non-saturating positive MR was observed. We have realized a magnetoresistive device that works at room temperature with simpler structure in a way different from other known metal-semiconductor hybrid devices. © 2009 IOP Publishing Ltd.