First hyperpolarizabilities dalton

Abstract: Second harmonic generation (SHG) is forbidden in centrosymmetric molecular materials. However, a signal is frequently observed from interfaces where the symmetry is broken. Whereas the effect can be phenomenologically accommodated, an ab initio qualitative and quantitative description has remained elusive, preventing the exploration of fascinating questions such as how deep below the surface the second harmonic can still be generated. To answer such questions, we present an ab initio multiscale approach to compute the total and layer-dependent intensity of surface SHG from molecular crystals. The microscopic origin of surface SHG is identified in layer-dependent models with embedding partial charges combined with density functional theory. The models show increasing symmetry-breaking distortions of the electron cloud around the molecules as the surface layer is approached. The SHG at the molecular level is determined using time-dependent density functional theory and then brought to the scale of macroscopic films through a rigorous self-consistent multiple scattering formalism capable of predicting the measurable optical intensities of the generated second harmonic signal. We study crystalline molecular films with centrosymmetric unit cells of 7,9-Dibromobenzo[h]quinolin-10-ol. The intensity of the SHG at the surface layer is two orders of magnitude larger than at the next layer below and three orders of magnitude larger than two layers below. Besides providing fundamental understanding, our approach can be used for designing and optimizing optical devices containing nonlinear molecular materials, such as molecular laminates. We show that a relatively basic Kretschmann-like setup can enhance the surface SHG of a crystalline film of centrosymmetric molecular unit cells a thousand times.

Cite this as

Krstic, Marjan (2023). Dataset: First hyperpolarizabilities dalton. https://doi.org/10.35097/1783

DOI retrieved: 2023

Additional Info

Field Value
Imported on November 28, 2024
Last update November 28, 2024
License CC BY 4.0 Attribution
Source https://doi.org/10.35097/1783
Author Krstic, Marjan
Given Name Marjan
Family Name Krstic
Source Creation 2023
Publishers
Krstic, Marjan
Production Year 2023
Publication Year 2023
Subject Areas
Name: Chemistry

Related Identifiers
Identifier: 10.48550/arXiv.2310.20297
Type: DOI
Relation: IsSupplementTo