Exfoliated MoS2 flakes

While bulk MoS2 in the 2H-phase is known to be an indirect-band gap semiconductor, monolayer MoS2 has a direct band gap. The layer-dependent optoelectronic properties of MoS2 have promoted much research in 2-dimensional MoS2-based devices. 2D MoS2 can be produced by exfoliating bulk crystals to produce single-layer to few-layer flakes through a dry, micromechanical process or solution processing. Micromechanical exfoliation, also pragmatically called "Scotch-tape exfoliation," involves using an adhesive material to repeatedly peel apart a layered crystal by overcoming the van der Waals forces. The crystal flakes can then be transferred from the adhesive film to a substrate. Konstantin Novoselov and Andre Geim first used this facile method to obtain graphene from graphite crystals. However, it can not be employed for uniform 1-D layers because of the weaker adhesion of MoS2 to the substrate (either Si, glass, or quartz). The scheme, as mentioned earlier, is good for graphene only. While Scotch tape is generally used as an adhesive, PDMS stamps can also satisfactorily cleave MoS2 if it is important to avoid contaminating the flakes with residual adhesive. Liquid-phase exfoliation can also produce monolayer to multi-layer MoS2 in solution. A few methods include lithium intercalation to delaminate the layers and sonication in a high-surface tension solvent. Molybdenum disulfide is a host for the formation of intercalation compounds. This behavior is relevant to its use as a cathode material in batteries. One example is a lithiated material, LixMoS2. With butyl lithium, the product is LiMoS2. If you are looking for high quality, high purity, and cost-effective Molybdenum disulfide, or if you require the latest price of Molybdenum disulfide, please feel free to email contact mis-asia.