Subcategory: Materials Science
Kory Beach - Rensselaer Polytechnic Institute
Co-Author(s): Michael Lucking, Rensselaer Polytechnic Institute, Troy, NY; Humberto Terrones, Rensselaer Polytechnic Institute, Troy, NY
Second harmonic generation (SHG) is a nonlinear optical process in materials that can potentially be used for optical fiber signal enhancement, laser frequency doubling, and nanostructured materials characterization. In the present study, first principles (density functional theory) methods are used to calculate the SHG spectra (χ(2)) of a variety of theoretical nanostructures and alloys in order to investigate the most interesting avenues of experimental exploration. The calculations are shown to be consistent with experimental data for pristine TMDs, justifying the use of this method for structures that have not yet been produced in the lab. These new structures include various alloys of transition metal dichalcogenide (TMD) monolayers, BN and BxCyNx alloy monolayers and nanotubes, as well as porous Schwarzite BN and TMD structures. Hypothetical Nb0.5Ta0.5S2 and NbSSe Haeckelite structures are found to have the highest χ(2) of all structures, BxCyNx alloys have higher SHG intensities than their BN counterparts, and BN Schwarzites exhibit stronger χ(2) than other known 3D materials. Moreover, careful examination of the relationship between the concentration of Se in MoxSeySz alloys shows that the SHG intensity can be tuned by modifying the stoichiometry. These results provide strong motivation for future research into these structures including attempting to synthesize the hypothetical materials experimentally, as well as to theoretically explore the effects of curvature, defects, and strain in these systems.ERN_conference_abstract_Kory_Beach_2017.docx
Funder Acknowledgement(s): National Science Foundation (EFRI-1433311)
Faculty Advisor: Humberto Terrones, firstname.lastname@example.org
Role: I calculated second harmonic spectra for the BN and BCN nanotubes, as well as for the control TMD monolayers that were used to compare our algorithm to the experimental data. I also wrote several sections of the paper corresponding to this talk, which has been submitted to the journal 2D Materials.