Negative Differential Resistance and Tunable Spin-Filtering Effects in Metalloporphyrin/Graphene Hybrids

Abstract

The recent synthesis of various hybrid porphyrin-graphene systems provides an attractive platform to investigate exotic transport phenomena related to graphene-based spintronic devices. Herein, we perform a systematic study of spin transport properties in metal-tetraphenyl-porphyrin (M-TPP, M=Cr, Mn, Fe, Co)/graphene hybrids with three types of contact configurations, which have been prepared by experiment (Sci. adv., 2019, 9, 33-38). The I-V curves show obvious negative differential resistance (NDR) effects that are robust against the change of contact configurations. Interestingly, all M-TPP/graphene hybrid systems exhibit strong spin-filtering effects at low bias voltage. Among them, hybrid M-TPP/graphene systems with Mn and Fe metal atoms exhibit a nearly 100% spin-filtering efficiency and spin-resolved NDR effects, and the spin polarization direction can be reversed by altering the central transition metal with Co. Our findings reveal the intriguing spin transport properties in M-TPP /graphene hybrid systems and suggest their potential application for realizing future multifunctional spin devices.

Keywords: Metalloporphyrin/graphene hybrids, Molecular device, Negative Differential Resistance, Spin filtering effect, First principles calculations