Dielectric Properties of Frequency Modulation Twisted Nematic LCDs Doped with Silver Nanoparticles

Abstract

Twisted nematic liquid crystal display (TN-LCD) devices, composed of nematic liquid crystal (NLC), doped with silver (Ag) nanoparticles, which are protected with the same NLC molecules of 5CB (Merck, K-15), show electrooptic characteristics that are featured by a frequency modulation and fast response. This device is called FM-TN-LCD. In this paper, we report that the frequency range in the FM-TN-LCD spreading from 40 Hz to an upper limit 2 kHz correlates with that of the dielectric dispersion of the sample cell, which is expressed analytically by the Maxwell–Wagner theory on the heterogeneous dielectric medium, where the dielectric relaxation frequency, and thus the dielectric relaxation time, are primarily governed by the electrical conductivity of the doped Ag nanoparticles.

Effect of ZnO nanoparticles on the SmC*-SmA* phase transition temperature in electroclinic liquid crystals

“…Liquid crystal displays (LCDs) doped with metal NPs such as silver (Ag), gold (Au), palladium (Pd), platinum (Pt), or their alloys exhibited faster response times [8][9][10][11][12] than those of LCDs with conventional driving methods.…”

Dielectric relaxation dynamics in liquid crystal – dye composites

“…Owing to their large optical anisotropy (i.e., birefringence) and dielectric anisotropy, NLCs have also been used to modulate refractive index by molecular reorientation with an external field or under the action of light [1]. Nowadays, to obtain materials with eutectic physical properties for displays or other optical devices, different additives such as carbon nanotubes [2][3][4], metal nanoparticles [5][6][7] and dyes [8][9][10] are doped in pure liquidcrystalline materials. Two main classes of aromatic dyes have enjoyed use as guests in LC mixtures as azo dyes have been employed as dopants in condensed optical materials intended for novel optoelectronic devices.…”

Effects of Nanoscaled Tin-Doped Indium Oxide on Liquid Crystals against Electrostatic Discharge

“…To obtain a higher display quality, the effects of fine particles added in LCs on the characteristics of the LCs have been investigated by several groups [1][2][3][4][5]. The chosen materials range from conducting materials [1,2] to insulating carbon nanotubes (CNTs) [3,4] and ferroelectric particles [5].…”

“…So far the subjects have included various kinds of materials such as metallic Ag-or Pd-nanoparticles [1,2], CNTs [3,4,[11][12][13], diamond particles [14], semiconductive nanotubes [15], cage-like polymeric molecules such as polyhedral oligomeric silsesquioxanes (POSS) [16,17], and ferroelectric particles [5,18]. By using these nanoparticle candidates, newly found texture, switching behavior, or enhanced electro-optical response for the modified LC can be achieved.…”