Progress in Physics of Applied Materials

Progress in Physics of Applied Materials

DFT Investigation of Electro-Optical Properties of a Novel Liquid Crystal Molecule Under Extraneous Electric Field (THz)

Document Type : Original Article

Authors
Yadupati Kushwaha 1
Satya bratt Pandey 2
Sachin Kumar Singh 2
Umesh Yadava 1
1 Department of Physics, DDU Gorakhpur University, Gorakhpur 273009, INDIA
2 Department of Chemistry, DDU Gorakhpur University, Gorakhpur 273009, INDIA
10.22075/ppam.2025.38335.1156
Abstract
This work presents theoretical investigations into the electro-optical response of an aroylhydrazone liquid crystal (LC) N-[2-Hydroxy-4-dodecylidene]-N′-[4′-dodecyloxybenzoyl]hydrazine (2HDDH) under the influence of terahertz (THz) range electric fields, a regime rarely explored for this class of materials. While previous studies on LC molecules have predominantly focused on static or low-frequency fields, the effect of high-frequency (THz) electric fields on their electro-optical properties remains largely unexplored, limiting the understanding of their potential in next-generation photonic and optoelectronic technologies. Using a theoretical framework originally developed for organic compounds and extended here to THz device contexts, we computed order parameter, birefringence, director angle, vertical electronic transitions, frontier molecular orbitals (HOMO–LUMO), and molecular electrostatic potential (MEP) surfaces. The finite field approach was employed to evaluate order parameter, birefringence, and magic angle, while DFT and TD-DFT calculations revealed high anisotropic polarizability (Δα = 466.45 Bohr³), a moderate dipole moment (μ = 5.67 D), and strong UV absorption. These results identify 2HDDH as a thermally stable, electro-optically active material with significant promise for THz-frequency optoelectronic applications, including advanced displays, sensors, and OLEDs.
Keywords
2HDDH
Liquid crystal
Order parameters
UV-vis spectra
TD-DFT
Subjects

© 2025 The Author(s). Progress in Physics of Applied Materials published by Semnan University Press. This is an open access article under the CC-BY 4.0 license. (https://creativecommons.org/licenses/by/4.0/)

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  • Receive Date 14 July 2025
  • Revise Date 09 August 2025
  • Accept Date 17 August 2025