Room temperature photosensitive ferromagnetic semiconductor using MoS₂

Two-dimensional semiconductors, including transition metal dichalcogenides (TMDs), are of interest in electronics and photonics but remain nonmagnetic in their intrinsic form. Atomic modulation using physical and chemical ways is an effective means to control the physical properties such as magnetic and electrical properties of two-dimensional materials which can be controlled by irradiation. Here we treat mechanically exfoliated MoS₂ with a helium ion beam, which exhibits semiconducting and ferromagnetic ordering at room temperature, while Monte Carlo simulations and theoretical calculations confirmed that the control of nanoholes result in the presence of magnetism. In addition, the irradiation results of multilayer MoS₂ show that the magnetic moment increases with the increase of 10 layers. The conductivity remains virtually unchanged before and after being treated by a helium ion beam. The treated MoS₂ spintronic device displays the switch of 'on/off' under the light, magnetic field, and/or electric field, which means 2D photosensitive ferromagnetic semiconductor functions are successfully demonstrated at room temperature.