Controlled n-doping of monolayer MoS2 by atomic hydrogen

Molybdenum Disulfide (MoS2) is a 2D layered material with potential applications in optoelectronics, electronics and spintronics. The injection of electrons in MoS2 is affected and limited by the Schottky barrier formed between metal contact and MoS2. There is a great deal of research interest to experimentally demonstrate ohmic contacts onto MoS2 in order to fully unravel the potential of this exciting material. We will present our results on controlled doping of single layer MoS2 surface by hydrogen to improve the contact resistance. We measured the transport properties of the MoS2 as a function of successive atomic hydrogen dosage at low temperature in ultra-high vacuum. Atomic hydrogen is generated using a hydrogen cracker. We observe that hydrogen adsorption results in negative doping due to charge donation by hydrogen to MoS2. Furthermore we will discuss the stability of atomic hydrogen on warming up the sample to room temperature.