Dielectric and Performance Analysis of CdTe Quantum Dots Doped Nematic Liquid Crystal

Year 2018, , 254 - 262, 31.01.2018

Oğuz Köysal , Gülsüm Kocakülah , Mert Yıldırım , Gülnur Önsal Özge Tüzün Özmen

https://doi.org/10.29130/dubited.360125

Cited By: 1

Abstract

In this work, cadmium telluride core type quantum dots (CdTe QDs) were
dispersed in 4-pentyl-4′-cyanobiphenyl (5CB) nematic liquid crystal (LC) with a
concentration of 0.05 % wt/wt; and their electrical and dielectric properties
were investigated by using admittance measurements in the frequency range of
100 Hz - 10 MHz. In order to determine the effects of CdTe QDs in 5CB nematic
LC, dielectric anisotropy (∆ε), crossover frequency (fcrossover), critical frequency (fcritical), real and imaginary parts of permittivity (ε'
and ε") of neat LC and CdTe QDs dispersed LC composites were obtained
using the experimental data. Moreover, threshold voltage (Vth),
splay elastic constant (K11) were also calculated. It was found that
Vth and K11 of QDs dispersed LC are significantly
decreased due to the existence of CdTe QDs.

 

Keywords

Nematic liquid crystal, quantum dot, electrical and dielectric properties

CdTe Kuantum Nokta Katkılı Nematik Sıvı Kristalin Dielektrik ve Performans Analizi

Abstract

Bu çalışmada çekirdek tipi kadmiyum tellür kuantum noktaları (CdTe QDs) ağırlıkça
% 0,05 oranında 5CB (4-pentil-4'-siyanobifenil) nematik sıvı kristale (LC) katkılanmış
ve elektrik ve dielektrik özellikleri 100 Hz-10 MHz frekans aralığında empedans
ölçümleri kullanılarak araştırılmıştır. CdTe kuantum noktaların 5CB nematik
sıvı kristal yapıda gösterdiği etkiyi belirlemek için dielektrik anizotropi
(Δε), çapraz frekans (fcrossover), kritik frekans (fkritik),
dielektrik sabiti (ε 've ε ") değerleri deneysel veriler kullanılarak elde
edilmiştir. Ayrıca, eşik voltajı (Vth) ve splay elastik sabiti (K11)
hesaplanmıştır. CdTe katkılanmasıyla eşik voltajı (Vth) ve eğilme elastik
sabiti (K11) önemli ölçüde azaldığı görülmüştür.

Keywords

Nematik sıvı kristal, kuantum nokta, elektrik ve dielektrik özellikler

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