Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.452833
Title: The crystal growth and properties of some chalcogenides of zinc and cadmium
Author: Cutter, J. R.
Awarding Body: Durham University
Current Institution: Durham University
Date of Award: 1977
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Abstract:
The main purpose of the work described in this thesis was to develop techniques for producing boules of ZnSe and ZnS(_x)Se(_1-x) suitable for research purposes. This was accomplished by extending the method that Clark and Woods((^1)) used for CdS to the higher temperatures needed to grow ZnS and ZnS(_x)Se(_1-x) in the range x = 0-0.6. In this system the capsule is connected to a reservoir of one of the components via a narrow orifice to maintain constant growth conditions. The system has been examined theoretically in an attempt to learn more about the actual conditions of growth within the capsule. It was concluded that growth occurs close to stoichiometry with(the ratio of P(_se2)/P(_zn) at the growth face) approximately 0.194 or 1.12 according to the element in the reservoir. Particular emphasis was placed upon the incorporation of manganese into the zinc selenide lattice. Concentrations of the order 300 p.p.m. were obtained when the element was added to the charge and MnCl(_2) was placed in the reservoir. Higher levels of manganese (~1%) were obtained using chemical vapour transport with iodine as the transport agent. Boules of solid solutions, within the range of compositions from ZnSe to ZnSe(_0.4)S(_0.6) were examined using a transmission electron microscope. The dominant crystallographic defects were found to change from thin twins to stacking faults as the amount of ZnS was increased. The origin of the defects was probably post growth stress. Finally, the anomalous photovoltaic effect was discovered in ZnSe needle crystals, and was explained qualitatively in terms of asymmetrical barriers along the polar axis of the crystal.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.452833  DOI: Not available
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