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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.

Crystal growth and charge carrier transport in liquid crystals and other novel organic semiconductors

Pokhrel, Chandra Prasad. January 2009 (has links)
Thesis (Ph.D.)--Kent State University, 2009. / Title from PDF t.p. (viewed April 1, 2010). Advisor: Brett Ellman. Keywords: Laser; Charge generation; Charge transport; Mobility; Trapping; Space charge; Hopping; Tunneling; Lattice vibration; Exciton; Polaron; HUMO; LUMO; Action Spectrum; Quantum efficiency; Crystal Growth; Liquid crystal; Disordered medium. Includes bibliographical references.

Organic metals : studies related to the synthesis of acceptors derived from TCNQ

Hammond, Gerald Bruce January 1979 (has links)
Since a report that the complex of TTF.TCNQ showed novel solid state properties including high room temperature conductivity, there has been considerable interest in the study of these so called "organic metals." This thesis describes the synthesis of new acceptors derived from TCNQ. First the synthesis of 2-methoxycarbonyl-7,7,8,8-tetracyanoquino-dimethane (56) is presented. Bromination of methyl 2,5-dimethylbenzoate followed by treatment with sodium cyanide yielded the dicyano compound 60 which was converted to the dihydro-TCNQ 62 via the corresponding phenylenetetracyanodiacetate intermediate. Oxidation of 62 afforded 2-methoxycarbonyl-7,7,8,8-tetracyanoquinodimethane (56), which was found to be unstable. The synthesis of 2,3-dimethoxycarbonyl-7,7,8,8-tetra-cyanoquinodimethane was attempted in the following manner: the Diels-Alder cyclization of trans,trans-2,4-hexadiene and dimethyl acetylenedi-carboxylate followed by dehydrogenation of the adduct gave dimethyl 3,6-dimethylphthalate. Benzylic bromination of this material followed by displacement of the bromines by cyanide yielded the dicyano compound 73. However, several attempts to convert 73 to the corresponding tetraester 78 were unsuccessful. The synthesis of 2,3-dimethyl-7,7,8,8-tetracyanoquinodimethane is presented. The intermediate 2,3-dimethylcyclohexane-l,4-dione (87) was prepared from 2,3-dimethylphenol by standard means. It was then condensed with malononitrile, and the product was treated with bromine/pyridine to give the dihydro-DMTCNQ 89. When this compound was treated with a mixture of palladium and sulfur at 180°C the desired 2,3-dimethyl-TCNQ 83 was obtained in low yield. The second part of this thesis describes the preparation of 11,11, 12 ,12-tetracyano-4,5,9,10-tetrahydropyreno-2,7-quinodimethane (TCNTP) from mesitylene. This compound was bisbrominated to give 3,5-bis-(bromomethyl)toluene, which was then coupled with 3,5-bis(mercaptomethyl)-toluene to produce the dithia[3.3jmetacyclophane 98. This was converted to the dimethyl[2.2]metacyclophane 96 via Wittig rearrangement followed by reduction with lithium in liquid ammonia. This cyclophane was then brominated and the resulting dibromo compound was converted to the corresponding dicyano-94. The latter compound was treated with bromine in the presence of iron powder to produce 2,7-bis(cyanomethyl)-4,5,9,10-tetrahydropyrene. Introduction of the remaining two nitrile groups was accomplished via use of the tetracyanodiacetate intermediate 92. Hydrolysis and decarboxylation of 92 followed by oxidation with NBS/triethylamine at -78°C furnished the desired TCNTP (90). / Science, Faculty of / Chemistry, Department of / Graduate

High performance organic thin film semiconductor devices: light emission properties and resonant tunnelingbehaviors

Zheng, Tianhang, Henry., 郑天航. January 2009 (has links)
published_or_final_version / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy

Femtosecond spectroscopy of conjugated polymers

Samuel, Ifor David William January 1991 (has links)
No description available.

Electrical, optical and gas sensor properties of chloroaluminium (ClAlPc)

Azim-Araghi, Mohammad Esmaeil January 1997 (has links)
No description available.

Photoexcitation and transport of charge carriers in Durham-route polyacetylene

Townsend, Paul David January 1987 (has links)
No description available.

Novel materials showing nonlinear optical behaviour

Breen, Gary Francis January 1992 (has links)
No description available.

Magnetic properties of TCNQ complexes

Qureshi, Saleem January 1990 (has links)
No description available.

Molecular engineering of organic semiconductors: design, synthesis, applications and stability. / 有機半導體的分子工程: 設計、合成、應用及穩定性 / CUHK electronic theses & dissertations collection / You ji ban dao ti de fen zi gong cheng: she ji, he cheng, ying yong ji wen ding xing

January 2011 (has links)
Liang, Zhixiong. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Organic chemistry and semiconductor physics of N-heteroacenes. / 氮雜並苯體系的有機化學合成及半導體物理研究 / CUHK electronic theses & dissertations collection / Dan za bing ben ti xi de you ji hua xue he cheng ji ban dao ti wu li yan jiu

January 2011 (has links)
Tang, Qin. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

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