Spin Transport and Spin Thermoelectric Transport in 2D Mn-Doped Blue Phosphorene with High Curie Temperature and Half-Metallicity

Abstract

Although 2D phosphorene has exhibited promising applications in electronic and optoelectronic devices with high carrier mobility and high on/off ratio, the nonmagnetism in pristine phosphorene hinders its potential applications in spintronic devices. In this work, using first-principles, Monte Carlo simulations, and the nonequilibrium Green’s function method, we investigate the structural, magnetic, and electronic properties as well as the spin transport and spin thermoelectric transport properties for Mn-doped monolayer blue phosphoren (Blue-P). We find that Mn-doped Blue-P is structurally stable and thermally stable, and it exhibits ferromagnetism above room temperature. Interestingly, the doped system is a half-metal with complete spin polarization of electrons around the Fermi level, which is robust with respect to the doping concentration. The spin transport properties indicate an excellent spin-filtering effect and a high magnetoresistance ratio (up to 105%), which are explained from the calculated bias-voltage- and spin-dependent band structures and the spin-dependent transmission eigenstates and pathways. In addition, the spin thermoelectric transport properties show a thermal spin filtering effect, a large spin Seebeck coefficient, and a low thermal conductivity. A high spin thermoelectric figure of merit accompanied by a small charge thermoelectric figure of merit can be obtained by adjusting the chemical potential and the temperature. These results suggest that 2D Mn-doped Blue-P is a promising candidate for versatile spintronic and spin caloritronic applications.

Perylene-based molecular device: multifunctional spintronic and spin caloritronic applications

“…We can see that the maximum values of the thermal MR reach up to 10 9 and 10 6 , which are much higher than that of the Mn-doped monolayer blue phosphorene (B10 5 ). 52 It is worth noting that the lowest MR also can reach 10 6 % and 10 4 %. Such large value of MR indicates that such device has excellent spin transport property of thermal colossal giant magnetoresistance effect.…”

“…Thus, such currents can be designed as a spin signal converter of the square wave. 52,53 The square wave can be used in switching signal. For example, in the magnetization PC, the large values of the spin-up current in the high platform and the nearly zero values of the spin-up current in the intermediate state can be used to represent the digit signal ''(1)-(0)'', respectively.…”

“…Fig.2(a) and (b). Thus, such currents can be designed as a spin signal converter of the square wave 52,53. The square wave can be used in switching signal.…”

Spin filtering effect, thermal spin diode effect and high tunneling magnetoresistance in the Au/GdI2/Au van der Waals junction

“…These computational methods have been extensively used in our previous works on 3D and 2D transport systems. 28–30…”

“…These computational methods have been extensively used in our previous works on 3D and 2D transport systems. [28][29][30] Fig. 1 The crystal structure (a) and spin-dependent FM (b) and AFM (c) band structures of bulk GdI 2 , and the structure of the magnetic tunnel junction Au/GdI 2 /Au (d).…”