2D Heterostructures via Selective-area Atomic Substitution
Ling group developed an atomic substitution method to convert layered transition metal dichalcogenides (e.g. MoS2) to ultrathin metal nitrides, extending the 2D family significantly. This project is to realize patterned MoS2 structure and MoS2-MoN heterostructure by controlling and tuning the reaction dynamics. For example, our research work shows that strained MoS2 reacts much faster compared to the unstrained area. If we could introduce patterned strain to MoS2 through the substrate design (e.g. fabricate nanopillars on the substrate), we would expect the strained MoS2 being etched or converted to MoNx during the atomic substitution process. Therefore, patterned MoS2 or MoS2-MoNx structures is expected through this “strain lithography”.
We also plan to explore the applications of the obtained structures. For example, MoNx is a highly conductive metallic material and can be used as electrodes for MoS2 field effect transistors (FETs). Through a rational design of the MoS2-MoNx heterostructure, we expect to form a high performance logic circuits based on MoNx contacted MoS2 FETs.
• Learn the material characterization tools such as Raman spectroscopy and the data analysis skills
Week 1: Synthesis and characterization training
Week 2: Independent operation of the synthesis
Week 3: Fabrication of the nanopillars
Week 4-5: Fabricate patterned MoS2 monolayers through the chemical reaction
Week 6: Characterization of the patterned MoS2
Week 7: Fabricate MoS2-MoNx lateral heterostructures through the chemical reaction
Week 8: Characterization of the heterostructure & wrap up