NM04: Atomically Thin, Layered and 2D Non-Carbon Materials and Systems

Vincent Vandalon, Eindhoven University of Technology

Second-Harmonic Generation and Raman Spectroscopy Probing Charge Density and Orientation of Atomic-Layered Deposited MoS₂

Written by Natalie Briggs

Atomic-layer deposition is a potential technique for scalable synthesis of layered materials such as molybdenum disulfide (MoS₂). However, this technique exhibits many challenges, and is largely limited to the synthesis of polycrystalline films. To understand such films resulting from atomic-layer deposition, crystal orientation must be studied. One technique through which grain orientation may be assessed is polarized Raman spectroscopy. Researchers as Eindhoven University of Technology have shown through simulation and experiment that the combination of parallel and cross polarized Raman spectroscopy can allow for the determination of crystal orientation in polycrystalline MoS₂ films through assessment of the ratio between A_1g(A′₁) and E_2g(E′) modes. Additionally, work at Eindhoven University of Technology shows that second-harmonic generation measurements can provide information regarding fixed charge density of MoS₂ films on c-Si/SiO₂ substrates, where previous research in the field has also demonstrated this technique for charge density determination in Al₂O₃.