Research On Spin Regulation And Transport Mechanism Of 2D Magnetoelectronic Materials

After entering the 21st century,the development of modern information technology has become the focus of the world’s attention.And due to the gradual failure of Moore’s Law,the traditional charge-based electronic devices will eventually disappear,so the development of high-speed,low-power new electronic information technology is imminent.Spintronic devices are the most promising of these.In this paper,the effects of elemental doping and applied strain on the spintronic properties of monolayer aluminum nitride（Al N）,boron phosphide（BP）layers,cubic zirconium dioxide（c-Zr O₂）nanosheets,and low-dimensional tin oxide（SnO₂）materials are investigated using first-principles calculations.In addition,the photovoltaic performance of doped zinc oxide（ZnO）thin-film solar cells has been investigated collaboratively.These studies provide a theoretical basis for exploring the magnetoelectronic properties of 2D materials and their related applications.The study found that:1)The Ti-doped Al N monomolecular layer generates a magnetic moment of 1μ_B,which is mainly contributed by the d orbitals of the impurity atom;the band gap of the Al N monolayer decreases with increasing strain;ferromagnetic and antiferromagnetic coupling oscillations occur at different Ti-Ti distances in the Al N monolayer.2)While Ti _P（P is substituted by Ti）can lead to BP monolayers that exhibit a semimetallic nature,Ti _B（B is substituted by Ti）has a lower formation energy;the magnetic moment generated by Ti _B is 1μ_B,which is also mainly contributed by the Ti-d orbitals;The band gap of the original BP monolayer increases with increasing strain;however,Ti _B causes the band gap of BP to first increase and then decrease after reaching 10%.In addition,Ti _B-Ti _B in BP monolayers always undergoes antiferromagnetic coupling at each distance,and further studies suggest that the Nair temperature of the Ti _B-containing BP system may be higher than at room temperature.3)The magnetic properties of TM-doped Zr O₂ nanosheets are mainly contributed by the d orbitals of TM atoms and the p orbitals of surrounding O atoms.When the Co-Co distances are 5.070?and 6.209?at the（110）surface and 7.170?and 9.485?at the（111）surface,these distances will produce Curie temperatures above room temperature.4)When V_O2c^（001）is introduced on the surface of SnO₂（001）,n-type defect states are generated in the band gap,and the magnetic moment of the system is 0μ_B.The magnetic moment of the system was 0 in the range of 10 percent compression to 8 percent stretch;while at 10%stretching,the surface appeared magnetic,and after applying 12%stretching,the magnetic moment of the system was reduced.As for the SnO₂（110）surface,the perfect system has a metallic energy band characteristic,and the system also has a sub-stable FM state.5)On the surface of SnO₂（110）,it turns the surface into a nonmagnetic insulator with a band gap after introducing V_O2c^（110）or V_O3c^（110）.In the study of strain,only the system containing V_O2c^（110）exhibits magnetic properties at 6%and 8%tensile strain.At 2%,4%,and 10%tensile strains,the system maintains the energy band characteristics of an insulator and the 6%and 8%tensile strains cause the system to spin polarization near the Fermi energy level;the band gap has disappeared,and the system transforms from a nonmagnetic insulator to a magnetic conductor.6)For the F,Al,and Ga co-doped ZnO films,the first principles confirm that F_O-Al _Zn-Ga _Zn is the most stable system,and the experimental scheme verifies the theoretical predictions.Compared with the reference indium-tin oxide film,the perovskite solar cells using FAGZnO film have higher J_SC and power conversion efficiency and,at the same time,show good performance and have good future application prospects.