Vanadium-Doped Molybdenum Diselenide Atomic Layers with Room-Temperature Ferromagnetism

Diluted two-dimensional magnetic semiconductors with high Curie temperature are highly sought after because of their potential applications in spintronics. Development of new techniques for preparation of high quality diluted magnetic semiconductors is critical for their applications. In this study, vanadium-doped molybdenum selenide, a new diluted magnetic semiconductor, was synthesized by a single-step chemical vapor deposition method. The merit of this method is that the molybdenum and vanadium precursors can be supplied to the growth substrate uniformly. Photoluminescence measurements reveal that the band gap of MoSe₂ decreases after doping, which can be attributed to the formation of impurity energy band caused by p-type doping at the valence band maximum. Thus, the V-doped MoSe₂ still maintains the semiconducting characteristics. Vibrating sample magnetometer studies clearly show the ferromagnetism of V-doped MoSe₂ at room temperature. DFT calculations illustrates the joint contribution of V dopants and nearby atoms to the magnetic moments. This study provides future prospects for the multifunctional application of two-dimensional materials.