The transport and optoelectronic properties of γ-graphyne-based molecular magnetic tunnel junctions

Abstract

By cutting γ-graphyne along different directions, two kinds of γ-graphyne nanodots (γ-GYNDs) can be acquired. In present study, using the γ-GYNDs we theoretically designed and investigated the spin-dependent transport properties of two kinds of molecular magnetic tunnel junctions (MMTJs). Depending on the orientation of γ-GYND and the connection way between γ-GYND and electrodes, our results show that two kinds of MMTJs have different microscopic transport mechanisms. Significant single or dual spin-filtering effects, giant magnetoresistances (reach 108%) and spin negative differential resistances can be observed in the MMTJs. In addition, the spin-polarized optoelectronic properties of the MMTJs have also been discussed, and the results indicate that the spin-polarized photocurrents are dependent on the polarization direction of light and magnetization directions of the electrodes. Especially, two different light-generated spins can be simultaneously produced in the MMTJs if the incident photons have given energies and they flow along opposite directions. The above findings show that the γ-graphyne-based MMTJs can be used as spintronic devices or opto-spintronic devices.