Tunable Doping in Hydrogenated Single Layered Molybdenum Disulfide

Abstract : Structural defects in the molybdenum disul-fide (MoS$_2$) monolayer are widely known for strongly altering its properties. Therefore, a deep understanding of these structural defects and how they affect MoS$_2$ electronic properties is of fundamental importance. Here, we report on the incorporation of atomic hydrogen in monolayered MoS$_2$ to tune its structural defects. We demonstrate that the electronic properties of single layer MoS$_2$ can be tuned from the intrinsic electron (n) to hole (p) doping via controlled exposure to atomic hydrogen at room temperature. Moreover, this hydrogenation process represents a viable technique to completely saturate the sulfur vacancies present in the MoS$_2$ flakes. The successful incorporation of hydrogen in MoS$_2$ leads to the modification of the electronic properties as evidenced by high resolution X-ray photoemission spectroscopy and density functional theory calculations. Micro-Raman spectroscopy and angle resolved photoemission spectroscopy measurements show the high quality of the hydrogenated MoS$_2$ confirming the efficiency of our hydrogenation process. These results demonstrate that the MoS$_2$ hydrogenation could be a significant and efficient way to achieve tunable doping of transition metal dichalcogenides (TMD) materials with non-TMD elements.