Enhancement the performance of liquid crystal switch by doping CdS quantum dot

Other Title(s)

تحسين أداء مفتاح السائل البلوري بواسطة التطعيم بمادة كبريتيد الكادميوم النانوي

Dissertant

Majid, Khulud Abd al-Husayn

Thesis advisor

al-Bassam, Sudad Salman Ahmad

University

University of Baghdad

Faculty

College of Science

Department

Department of Physics

University Country

Iraq

Degree

Master

Degree Date

2014

English Abstract

The electrical and optical properties of liquid crystal were studied because of a great interest of the possible opto-elecrtic of liquid crystal application.

Doping form of liquid crystals (4-Cyano-4'-pentylbiphenyl (5CB) molecule) was achieved by including adding a type of semiconductor nanoparticles with known ratios in the liquid crystal.

The semiconductor made on the enhancement of electrooptical liquid crystal properties.

Interaction between nanomaterials and liquid crystals can be making an optical composite therefore lead to changes in optical properties which can be tuned to get good characteristics in device or instrument.

The modifying of electro-optical properties of liquid crystal includes the decreasing of threshold voltage from 1.5 V (pure liquid crystal) to 1 V (doped liquid crystal) and fast response time 5 ms (pure liquid crystal) to 3 ms (doped liquid crystal) at room temperature.

Photoluminescence, and UV-visible measurement were used for calculation of the Eg of the CdS.

XRD was used to calculate the particles grain size, finally the Atomic Force Microscope used to evaluate the average roughness and root mean square.

The chemical method has been taken for getting the nanoparticles and using some of catalysts such as Oleic Acid (Oleic Acid is available) to reduce the roughness of CdS nanoparticles that is means rearrangement of the surface of nanoparticles as a result the grain size reaches to 11.63 nm.

Main Subjects

Physics

No. of Pages

72

Table of Contents

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Language

English

Data Type

Arab Theses

Record ID

BIM-607329