Substrate Interference and Strain in the Second-Harmonic Generation from MoSe₂ Monolayers.

ABSTRACT: Nonlinear optical materials of atomic thickness, such as non-centrosymmetric 2H transition metal dichalcogenide monolayers, have a second-order nonlinear susceptibility (χ⁽²⁾) whose intensity can be tuned by strain. However, whether χ⁽²⁾ is enhanced or reduced by tensile strain is a subject of conflicting reports. Here, we grow high-quality MoSe₂ monolayers under controlled biaxial strain created by two different substrates and study their linear and nonlinear optical responses with a combination of experimental and theoretical approaches. Up to a 15-fold overall enhancement in second-harmonic generation (SHG) intensity is observed from MoSe₂ monolayers grown on SiO₂ when compared to its value on a Si₃N₄ substrate

SUBMITTER: Puri S 

PROVIDER: S-EPMC11487631 | biostudies-literature | 2024 Oct

REPOSITORIES: biostudies-literature