P-type Transition-metal Doping Of Two-dimensional MoS₂

Molybdenum disulfide(MoS2)is a layered transition metal materials.As its thickness is reduced to monolayer M0S2.its band gap is changed from indirect to direct.C'olmparccd to graphene with zero band gap,the bandgap 0f 2D MoS2can be controlled by the number of layer.2D M0S2 have widely potential applications,such as light detectors,solar cells,sensors,field effect transistors,catalysis,photovoltaic cells,optoelectronic devices etc.However,the two-dimensional MoS2 is n-type electrical transport semiconductor with low PL efficiency,which is restrict its applications in phototronics.Therefore,a big challenge of these materials is how to realize bipolar electrical transport properties and enhance the PL quantum efficiency.Here,we used transition metal zinc as a p-type dopant to grown p-type 2D MoS2 films by chemical vapor deposition(CVD).Moreover,we also synthesized undoped 2D MoS2 films with few layers to compared with the Zn-doped MoS2-Raman spectra and photoluminescence spectra were used to obtain the polarity changes of 2D MoS2 films before and after doping.As a result,we found that doping zinc resulted in obvious enhancement of the PL quantum efficiency,indicatng that Zinc doped 2D MoS2 is p-type semiconductor.The result provides the possibility to form two-dimensional p-n heterostructures.Moreover,we also study the relationship between the angle of different shapes and the different types edge atoms.Because the crystal shape and edge of monolayer MoS2 domains have an obvious influence of their edge magnetism and electronic structures.Therefore,it is important to find the conditions and laws of different edges formation of molybdenum disulfide.