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Ehsan Soheyli

Ehsan Soheyli

Academic rank: Assistant Professor
ORCID: https://orcid.org/0000-0002-1403-7934
Education: PhD.
ScopusId: 56241255900
HIndex: 16/00
Faculty: Basic Science
Address:
Phone:

Research

Title
Enhanced dielectric and electro-optical switching properties of nematic liquid crystals using ZnCdTeS quantum dots with luminescent property at different emission wavelengths
Type
JournalPaper
Keywords
Nematic liquid crystals ,dielectric properties,electro-optical properties,threshold voltage
Year
2024
Journal نانومقیاس
DOI
Researchers zahra seidalilir ، Sepideh Shishehbor ، Ehsan Soheyli ، Mohammad Sabaeian

Abstract

In this study, ZnCdTeS quantum dots (QDs) with luminescent properties at different emission wavelengths were utilized to enhance the dielectric and electro-optical characteristics of nematic liquid crystal (NLC) cells. At various temperatures, the dielectric permittivity components (ɛ‖ and ɛꓕ) and dielectric anisotropy (Δɛ) of NLC samples containing ZnCdTeS QDs were measured. ɛ‖ increases considerably more than ɛꓕ in the nematic phase when QDs are introduced. The dielectric anisotropy of the system has increased by approximately 19% in the presence of QDs with red emission, which is a result of a significant enhancement of ɛ‖. The NLC environment induces one-dimensional arrays of QDs in the system, which enhances the dielectric properties of the system, as demonstrated by the dielectric results. The electro-optical findings indicate that including QDs substantially reduces the threshold voltage of NLC cells. Incorporating quantum dots into liquid crystal led to a reduction in the threshold voltage from 2.57 V for pure NLC to 2.21 V. QDs improve the effective field of a system by reducing the screening effects caused by ionic impurities in the system. Anisotropy enhancement, effective field increase within the cell, and QD-NLC interaction improvement all contribute to the enhancement of the cell's switching characteristics.