Characterization and device applications of II-VI nanocomposites

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2001.

Bibliographic Details
Main Author: Heine, Jason Randall, 1972-
Other Authors: Klavs F. Jensen.
Format: Thesis
Language:eng
Published: Massachusetts Institute of Technology 2005
Subjects:
Online Access:http://hdl.handle.net/1721.1/8447
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author Heine, Jason Randall, 1972-
author2 Klavs F. Jensen.
author_facet Klavs F. Jensen.
Heine, Jason Randall, 1972-
author_sort Heine, Jason Randall, 1972-
collection MIT
description Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2001.
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spelling mit-1721.1/84472019-04-12T09:35:19Z Characterization and device applications of II-VI nanocomposites Heine, Jason Randall, 1972- Klavs F. Jensen. Massachusetts Institute of Technology. Dept. of Materials Science and Engineering. Massachusetts Institute of Technology. Dept. of Materials Science and Engineering. Materials Science and Engineering. Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2001. Includes bibliographical references. This thesis describes the synthesis and characterization of CdSe core - ZnS shell (CdSe)ZnS nanocrystals, which behave as quantum dots (QDs), their incorporation into transparent polymers and ZnS, and possible device applications of the resulting luminescent materials. The crystalline structure of these quantum dots is examined using XRD. The nature of the core-shell interface is inferred by comparison of the XRD spectra with calculated spectra and in consideration of TEM images of the QDs. The influence the addition of a shell material over the CdSe core has on the QD exciton energy is examined by comparing the measured and calculated change in band edge emission energy when ZnS or CdS are used as overcoat materials. Methods of incorporating the QDs into various polymers are considered and the emission of a GaN LED/ QD-containing polymer composite structure is simulated and compared with the output of actual devices. The simulation is also used as a design tool in the production of a white-light LED. Embedding the QDs into ZnS films via an electrospray technique is carried out and the resulting films characterized with x-ray diffraction and photoluminesence measurements. QD film / ZnS film structures are also considered, with atomic layer deposition used as the method for depositing the ZnS to improve the film uniformity as well as to maintain high quality deposition at temperatures low enough to be compatible with the presence of QDs. Finally, thin film devices are synthesized and the behavior of the QD photoluminescence when an electric field is applied is studied. (cont.) Significant levels of photoluminescence quenching is observed when a voltage is applied across an ITO/ZnS/QD/ZnS/Al, and similar, devices. Various reasons for this quenching are considered. by Jason Randall Heine. Ph.D. 2005-08-23T20:15:29Z 2005-08-23T20:15:29Z 2001 2001 Thesis http://hdl.handle.net/1721.1/8447 50659435 eng M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582 121 p. 8392211 bytes 8391966 bytes application/pdf application/pdf application/pdf Massachusetts Institute of Technology
spellingShingle Materials Science and Engineering.
Heine, Jason Randall, 1972-
Characterization and device applications of II-VI nanocomposites
title Characterization and device applications of II-VI nanocomposites
title_full Characterization and device applications of II-VI nanocomposites
title_fullStr Characterization and device applications of II-VI nanocomposites
title_full_unstemmed Characterization and device applications of II-VI nanocomposites
title_short Characterization and device applications of II-VI nanocomposites
title_sort characterization and device applications of ii vi nanocomposites
topic Materials Science and Engineering.
url http://hdl.handle.net/1721.1/8447
work_keys_str_mv AT heinejasonrandall1972 characterizationanddeviceapplicationsofiivinanocomposites