Magnetic state dependent transient lateral photovoltaic effect in patterned ferromagnetic metal-oxide-semiconductor films

TL;DR

This study explores how an external magnetic field affects the transient lateral photovoltaic effect in patterned ferromagnetic Co lines on silicon, revealing magnetization-dependent magnitude and phase changes with potential for advanced magnetic sensors.

Contribution

It demonstrates experimentally and through simulations that the T-LPE magnitude depends on Co magnetoresistance and its phase on Lorentz force effects, introducing magnetic control of photovoltaic responses.

Findings

T-LPE magnitude is influenced by Co anisotropic magnetoresistance.

Dephasing of T-LPE is affected by Lorentz force acting on photocarriers.

Magnetic field can tune the phase and magnitude of the photovoltaic response.

Abstract

We investigate the influence of an external magnetic field on the magnitude and dephasing of the transient lateral photovoltaic effect (T-LPE) in lithographically patterned Co lines of widths of a few microns grown over naturally passivated p-type Si(100). The T-LPE peak-to-peak magnitude and dephasing, measured by lock-in or through the characteristic time of laser OFF exponential relaxation, exhibit a notable influence of the magnetization direction of the ferromagnetic overlayer. We show experimentally and by numerical simulations that the T-LPE magnitude is determined by the Co anisotropic magnetoresistance. On the other hand, the magnetic field dependence of the dephasing could be described by the influence of the Lorentz force acting perpendiculary to both the Co magnetization and the photocarrier drift directions. Our findings could stimulate the development of fast position sensitive detectors with magnetically tuned magnitude and phase responses.