Fabrication and structural, optical, and electrical characterization of multisource evaporated copper-gallium-selenide polycrystalline thin films.

Persistent Link:
http://hdl.handle.net/10150/184745
Title:
Fabrication and structural, optical, and electrical characterization of multisource evaporated copper-gallium-selenide polycrystalline thin films.
Author:
Albin, David Scott.
Issue Date:
1989
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Theoretical considerations for the use of chalcopyrite ternary I-III-VI₂ compounds in heterojunction photovoltaic conversion devices are presented, followed by an in-depth study of the structural, optical, and electrical characteristics of multi-source evaporated CuGaSe₂ thin films as determined by processing. Film composition was identified as the primary variable for affecting the microstructure and optical-electrical behavior of the films. Film composition was in turn dependent upon elemental flux rates and substrate related effects. Films deposited on glass and bare alumina substrates were richer in selenium than films deposited on molybdenum coated substrates. Cu-poor, near stoichiometeric, and Cu-rich compositions were obtained by varying the Cu/Ga flux ratio. Cu-poor films deposited on bare ceramic substrates were characterized by secondary impurity phase content and a tendency for cubic CuGaSe₂ formation. The cubic nature of optically thin films deposited on glass was substantiated by a lack of crystal field splitting of the valence band as observed by optical absorption measurements. Cubic-tetragonal phase behavior was monitored on optically opaque samples by observation of intensity-independent (112)/(111) x-ray diffraction peak shifts. Cu-poor films on glass were also characterized by surfaces pitting at substrate temperatures in excess of 450°C which may be related to the high surface energy of gallium. Cu-poor films deposited on molybdenum coated alumina substrates exhibited less impurity phase formation and were largely single-phase tetragonal CuGaSe₂. Cu-rich films on all substrates contained CuₓSe impurities and tetragonal CuGaSe₂.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Thin films, Multilayered.; Chalcopyrite crystals.; Semiconductors -- Junctions.; Photovoltaic cells.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Natural Science and Engineering; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Risbud, Subhash

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleFabrication and structural, optical, and electrical characterization of multisource evaporated copper-gallium-selenide polycrystalline thin films.en_US
dc.creatorAlbin, David Scott.en_US
dc.contributor.authorAlbin, David Scott.en_US
dc.date.issued1989en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractTheoretical considerations for the use of chalcopyrite ternary I-III-VI₂ compounds in heterojunction photovoltaic conversion devices are presented, followed by an in-depth study of the structural, optical, and electrical characteristics of multi-source evaporated CuGaSe₂ thin films as determined by processing. Film composition was identified as the primary variable for affecting the microstructure and optical-electrical behavior of the films. Film composition was in turn dependent upon elemental flux rates and substrate related effects. Films deposited on glass and bare alumina substrates were richer in selenium than films deposited on molybdenum coated substrates. Cu-poor, near stoichiometeric, and Cu-rich compositions were obtained by varying the Cu/Ga flux ratio. Cu-poor films deposited on bare ceramic substrates were characterized by secondary impurity phase content and a tendency for cubic CuGaSe₂ formation. The cubic nature of optically thin films deposited on glass was substantiated by a lack of crystal field splitting of the valence band as observed by optical absorption measurements. Cubic-tetragonal phase behavior was monitored on optically opaque samples by observation of intensity-independent (112)/(111) x-ray diffraction peak shifts. Cu-poor films on glass were also characterized by surfaces pitting at substrate temperatures in excess of 450°C which may be related to the high surface energy of gallium. Cu-poor films deposited on molybdenum coated alumina substrates exhibited less impurity phase formation and were largely single-phase tetragonal CuGaSe₂. Cu-rich films on all substrates contained CuₓSe impurities and tetragonal CuGaSe₂.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectThin films, Multilayered.en_US
dc.subjectChalcopyrite crystals.en_US
dc.subjectSemiconductors -- Junctions.en_US
dc.subjectPhotovoltaic cells.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineNatural Science and Engineeringen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorRisbud, Subhashen_US
dc.contributor.committeememberDemer, Louisen_US
dc.contributor.committeememberLynch, David C.en_US
dc.contributor.committeememberHamilton, Douglas Jen_US
dc.contributor.committeememberO'Hanlon, Johnen_US
dc.identifier.proquest9000125en_US
dc.identifier.oclc702670136en_US
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