Theoretical investigation of spin-dependent electron transport properties of dibromobenzene based positional isomers

Abstract Understanding the spin-dependent electron transport through a single molecular junction will provide in-depth knowledge to construct efficient molecular spintronic devices. The electron transport in such junction highly depends upon the structure of the molecule. The Density Functional Theory (DFT) combined with Non-Equilibrium Green's Function (NEGF) utilized to investigate the spin-dependent electron transport properties of positional isomers namely 4,6‐dibromobenzene‐1,3‐dithiol; 2,4‐dibromobenzene‐1,3‐dithiol and 2,5-dibromobenzene-1,3-dithiol. We have calculated several parameters such as the density of states, current–voltage characteristic, magnetoresistance effect etc. of these molecular junctions to understand the nature of electron transport. The projected density of states of the molecule and the total density of states shows that these molecules have good coupling with the electrode. Under the applied bias, we observed a variation of spin up and spin down transmission which leads to magnetoresistance effect in these molecular junctions. Among these molecules, the 2,5-dibromobenzene-1,3-thiol molecular junction shows a higher magnetoresistance effect than 4,6‐dibromobenzene‐1,3‐dithiol and 2,4‐dibromobenzene‐1,3‐dithiol. Hence, 2,5-dibromobenzene-1,3-thiol can be a good candidate for spintronic applications.