Enhancing Ferromagnetism and Tuning Electronic Properties of CrI3 Monolayers by Adsorption of Transition-Metal Atoms

Among first experimentally discovered two-dimensional (2D) ferromagnetic materials, chromium triiodide (CrI 3 ) monolayers have attracted particular attention due to their potential applications in electronics and spintronics. However, the Curie temperature T c of the CrI 3 monolayer is below room temperature, which greatly limits practical development of the devices. Herein, using density functional theory calculation, we explore how the electronic and magnetic properties of CrI 3 monolayers change upon adsorption of 3d transition-metal (TM) atoms (from Sc to Zn). Our results indicate that the electronic properties of the TM–CrI 3 system can be tuned from semiconductor to metal/half-metal/spin gapless semiconductor depending on the choice of the adsorbed TM atoms. Moreover, the adsorption can improve the ferromagnetic stability of CrI 3 monolayers by increasing both magnetic moments and T c . Notably, T c of CrI 3 with Sc and V adatoms can be increased by nearly a factor of 3. We suggest postsynthesis doping of 2D CrI 3 by deposition of TM atoms as a new route toward potential applications of TM–CrI 3 systems in nanoelectronic and spintronic devices.