Spin transport characteristics and photoelectric properties of magnetic semiconductor NiBr<sub>2</sub> monolayer

Abstract

Magnetic semiconductor materials have potential applications in spintronic devices. In this work, some nano-device structures based on the magnetic semiconductor NiBr<sub>2</sub> monolayer (NiBr<sub>2</sub>-ML) are designed, their spin-resolved transport and photoelectric properties are studied by using density functional theory combined with non-equilibrium Green’s function method. The results show that both the NiBr<sub>2</sub>-ML PN-junction diodes and sub-3 nanometer PIN-junction field-effect transistors (FETs) exhibit the significant rectification and spin filtering effects in either the armchair or the zigzag direction. The gates can obviously tune the electron transmission of the PIN-junction FETs. The current is significantly suppressed with the increase of gate voltage. In addition, NiBr<sub>2</sub>-ML has a strong response to the blue and green light, thus its phototransistor can generate a strong photocurrent under the irradiation of blue and green light. The research results in this paper reveal the multifunctional characteristics of NiBr<sub>2</sub>-ML, which provides an important reference for the application of nickel-based dihalides in semiconductor spintronic devices and optoelectronic devices.