Experimentally Mapping the Elemental Doping of MoS₂ Monolayer.

Abstract

For the atomically thin 2D semiconductors with great potentials in the post Moore's era, the doping is a prerequisite for the device engineering and integration. Limited by the doping approaches, elemental doping of 2D semiconductors has not been fully explored. Here, by using a liquid phase edge epitaxy method which can dissolve the dopants in the liquid phase, we have succeeded in doping MoS₂ monolayer with more than 40 elements (including transition metals, lanthanides, and main group elements). In this doping library, rarely observed p-type transport behavior has been obtained in Ti, Zn, and Au doped MoS₂ monolayers. While Cu, Ga, Zr, Nb, In, Sn, Hf, Ta, Pb, Bi and rare earth of Eu, Gd, Tm, Lu doped MoS₂ monolayers have showed low on/off ratios (<10). The obtained p-type, n-type and metallic MoS₂ monolayers enables future all-MoS₂ based device integration. Additionally, rare earth of Ce, Nd, Dy and Ho doped MoS₂ monolayers have showed soft magnetization with semiconducting transport behavior. At last, DFT calculations have revealed that the preferred doping configurations varies for different elements from Mo-substitution, S-substitution to S-site adsorption.