Bound hole states associated to individual vanadium atoms incorporated into monolayer WSe$_2$

Gate modulation of the long-range magnetic order in a vanadium-doped WSe2 semiconductor

We demonstrate the gate-tunability of the long-range magnetic order in a p-type V-doped WSe2 monolayer using ab initio calculations. We found that at a low V-doping concentration limit, the long-range ferromagnetic order is enhanced by increasing the hole density. In contrast, the short-range antiferromagnetic order is manifested at a high electron density by full compensation of the p-type V doping concentration. The hole-mediated long-range magnetic exchange is ~70 meV, thus strongly suggesting the ferromagnetism in V-doped WSe2 at room temperature. Our findings on strong coupling between ch…

Room-temperature ferromagnetism in monolayer WSe2 semiconductor via vanadium dopant

Diluted magnetic semiconductors including Mn-doped GaAs are attractive for gate-controlled spintronics but Curie transition at room temperature with long-range ferromagnetic order is still debatable to date. Here, we report the room-temperature ferromagnetic domains with long-range order in semiconducting V-doped WSe2 monolayer synthesized by chemical vapor deposition. Ferromagnetic order is manifested using magnetic force microscopy up to 360K, while retaining high on/off current ratio of ~105 at 0.1% V-doping concentration. The V-substitution to W sites keep a V-V separation distance of 5 nm…

Tunable Ferromagnetism and Thermally Induced Spin Flip in Vanadium-doped Tungsten Diselenide Monolayers at Room Temperature

The outstanding optoelectronic and valleytronic properties of transition metal dichalcogenides (TMDs) have triggered intense research efforts by the scientific community. An alternative to induce long-range ferromagnetism (FM) in TMDs is by introducing magnetic dopants to form a dilute magnetic semiconductor. Enhancing ferromagnetism in these semiconductors not only represents a key step towards modern TMD-based spintronics, but also enables exploration of new and exciting dimensionality-driven magnetic phenomena. To this end, we show tunable ferromagnetism at room temperature and a thermally …

利用4D-STEM对单层WSe$_2$中单个钒掺杂原子诱导的负电荷进行原子尺度成像

Atomic scale imaging of the negative charge induced by a single vanadium dopant atom in monolayer WSe$_2$ using 4D-STEM

本研究利用4D-STEM对单层WSe2中单个钒掺杂原子诱导的负电荷进行原子尺度成像，通过质心重建和模拟比较，实现了对掺杂剂电荷态的检测与分析。

Tunable Doping of Rhenium and Vanadium into Transition Metal Dichalcogenides for Two-Dimensional Electronics

Two-dimensional (2D) transition metal dichalcogenides (TMDCs) with unique electrical properties are fascinating materials used for future electronics. However, the strong Fermi level pinning effect at the interface of TMDCs and metal electrodes always leads to high contact resistance, which seriously hinders their application in 2D electronics. One effective way to overcome this is to use metallic TMDCs or transferred metal electrodes as van der Waals (vdW) contacts. Alternatively, using highly conductive doped TMDCs will have a profound impact on the contact engineering of 2D electronics. Her…

硒化V₂O₅/WO₃双层用于调节WSe₂薄膜的光电响应

Selenization of V$_2$O$_5$/WO$_3$ Bilayers for Tuned Optoelectronic Response of WSe$_2$ Films

通过硒化预沉积的V₂O₅/WO₃薄膜实现WSe₂掺钒，调控其电输运和光电响应，提升空穴导电性并实现绝缘体到金属的转变。