Fe‑Doped Triphenyl-Substituted Triazine Graphdiyne Semiconductor with Room‑Temperature Ferromagnetism

Abstract

Abstract The modulation of ferromagnetic order in 2D carbon materials has attracted increasing attention for the development of next-generation spintronic devices and multifunctional information storage technologies. In particular, the graphdiyne (GDY) family has been regarded as more suitable for spintronics owing to its tunable electronic structure and intrinsic semiconductor behavior. However, the effective magnetic introduction methods and their applications in specific devices have always been a challenge for the development of such materials. Here, this study presents a nitrogen-substituted derivative of GDY, triphenyl-substituted triazine graphdiyne (TPTG), as an ideal platform for inducing transition-metal iron (Fe) atoms to modulate the electronic state, resulting in the coexistence of room-temperature ferromagnetism and a semiconductor energy band. Subsequent spin-polarized density functional theory calculations further reveal that the observed ferromagnetism arises from pronounced localized magnetic moments together with electron transfer between carbon atoms and Fe ions. Moreover, by employing a transfer strategy suitable for this material system, thin films were successfully transferred onto a silicon substrate to construct an Fe-doped TPTG-based electronic device. Such a device exhibits typical artificial synaptic behavior under optical stimulation and demonstrates nonvolatile memory characteristics after illumination is removed, enabling the transition from short-term plasticity (STP) to long-term plasticity (LTP). The coexistence of ferromagnetism and semiconducting properties not only makes GDY-based materials promising candidates for exploring physical phenomena but also offers opportunities for the development of carbon-based neuromorphic devices.