## Reference
### Tip-Enhanced Optical Nano-Imaging of 2D Alloys  
[PERSON] 1 and [PERSON] 1,2  
1 Department of Physics, University of South Florida, Tampa, FL 33620, USA  
2 Department of Medical Engineering, University of South Florida, Tampa, FL 33630, USA  
Atomically thin transition metal dichalcogenides (TMDs) are two-dimensional (2D) materials with interesting optoelectronic properties including the tunable band gap that could be used in a variety of applications. We demonstrate a systematic control of the nano-optical properties of 2D TMDs with tunable chemical composition Mo(x)W(1-x)S2 alloys grown on Si/SiO\({}_{2}\) substrates. Photoluminescence (PL) signals have shown the PL peak shift as a function of the composition. Tip-enhanced photoluminescence (TEPL) imaging has been used for obtaining the higher spatial resolution beyond the diffraction limit. Quenching of the TEPL signals was observed for the higher Mo concentration revealing the tunneling electron injection in the quantum plasmonic regime. The comparison of the correlated AFM and TEPL images provides information about the lateral confinement of excitons, which could exhibit interesting optical properties. Multifunctional 2D PtSe\({}_{2}\) Layer Kirigami Conductors with 2000% Stretchability and Metallic-to-Semiconducting Tunability  
[PERSON] 1,2,4, [PERSON] 1,3,4, [PERSON] 1, [PERSON] 4, [PERSON] 3, [PERSON] 1,2, [PERSON] 1, [PERSON] 3, [PERSON] 3, [PERSON] 3, [PERSON] 1,5,6, [PERSON] 3 and [PERSON] 1,2,6  
1 NanoScience Technology Center, University of Central Florida, Orlando, Florida 32826, USA  
2 Department of Electrical and Computer Engineering, University of Central Florida, Orlando, Florida 32816, USA  
3 Department of Material Science and Engineering, Seoul National University, Seoul 08826, South Korea  
4 Analytical Research Division, Korea Basic Science Institute, Jeonju 54907, South Korea  
5 Department of Chemistry, University of Central Florida, Orlando, Florida 32816, USA  
6 Department of Materials Science and Engineering, University of Central Florida, Orlando, Florida 32816, USA  
Two-dimensional transition metal dichalcogenide (2D TMD) layers are highly attractive for emerging stretchable and foldable electronics owing to their extremely small thickness coupled with extraordinary electrical and optical properties. Although intrinsically large strain limits are projected in them, i.e., several times greater than silicon, integrating 2D TMDs in their pristine forms does not realize superior mechanical tolerance greatly demanded in high-end stretchable and foldable devices of unconventional form factors. In this article, we report a versatile and rational strategy to convert 2D TMDs of limited mechanical tolerance to tailored 3D structures with extremely large mechanical stretchability accompanying well-preserved electrical integrity and modulated transport properties. We employed a concept of strain engineering inspired by an ancient paper-cutting art, known as kirigami patterning, and developed 2D TMDs-based kirigami electrical conductors. Specifically, we directly integrated 2D platinum diselenide (2D PtSe\({}_{2}\)) layers of controlled carrier transport characteristics on mechanically flexible polyimide (PI) substrates by taking advantage of their low synthesis temperature. The metallic 2D PtSe\({}_{2}\)/PI kirigami patterns of optimized dimensions exhibit an extremely large stretchability of \(\sim\)2000% without compromising their intrinsic electrical conductance. They also present strain-tunable and reversible photo-responsiveness when interfaced with semiconducting carbon nanotubes (CNTs) benefiting from the formation of 2D PtSe\({}_{2}\)/CNT Schottky junctions. Moreover, kirigami field-effect-transistors (FETs) employing semiconducting 2D PtSe\({}_{2}\) layers exhibit tunable gate responses coupled with mechanical stretching upon electrolytes gating. The exclusive role of the kirigami pattern parameters on resulting mechano-electrical responses was also verified by finite-element modeling (FEM) simulation.