| About this Abstract | 
   
    | Meeting | MS&T23: Materials Science & Technology | 
   
    | Symposium | Controlled Synthesis, Processing, and Applications of Structural and Functional Nanomaterials | 
   
    | Presentation Title | Unveiling Nanoscale Strain in Two-dimensional Semiconductors via Near-field Optical Microscopy | 
   
    | Author(s) | Jin Myung  Kim, Peiwen Jos Ma, Soyeong  Kwon, SungWoo  Nam | 
   
    | On-Site Speaker (Planned) | SungWoo  Nam | 
   
    | Abstract Scope | Two-dimensional (2D) transition metal dichalcogenides (TMDs) have received considerable attention as an appealing platform of next-generation electronic and optoelectronic devices. Particularly, controlled deformation of their crystal lattice is essential to enable quantum optics applications, such as single photon emission, while precise and non-destructive characterizations of nanoscale strain remain as a significant challenge. Here, we investigate optical characterization of strained 2D semiconductors via near-field photo-induced force microscopy (PiFM). PiFM allows us to analyze nanoscale absorption properties by measuring light-induced dipole interaction force between a metallic tip and a sample. Our PiFM mapping and spectroscopy revealed the strong resonance of A and B excitons in 2D TMDs. In addition, PiFM hyperspectral line scanning on buckle delaminated TMDs showed strain-induced energy shift across sub-micron buckle structure whereas conventional photoluminescence scanning was unable to resolve energy shift. These results pave the way for nanoscale strain analysis of 2D semiconductors beyond optical diffraction limit. |