Light-Induced-Magnetoresistance in p-n Junction Device

It is highly desirable to provide extra functionality for p-n junction to bypass the limits to Moore's law. By combining magnetoelectric and photovoltaic effects of p-n junctions, we demonstrate a novel light-induced magnetoresistance (MR) effect, that the photovoltage in the conventional p-n junction can be significantly tuned by magnetic field. In contrast to the symmetric MR driven by external electric field, light-induced MR presents an asymmetric behavior at positive and negative magnetic induction. Theoretical fits using photovoltaic transport equations further reveal that the asymmetric MR induced by light directly reflects the asymmetric geometric of the space-charge region in p-n junction under the magnetic induction. The results not only further confirm our MR model of p-n junction, but also provide a new route by using magnetic control of energy flow in light harvest.