{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/77338"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/77338","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Disorder Effects in Aluminum-Gallium - Arsenide Quantum-Well Heterostructures","abstract":"The effects of disorder on the luminescence and laser properties of Al(,x)Ga(,1-x)As-GaAs (or AlAs-GaAs) quantum-well heterostructures (QWH's) grown by metalorganic chemical vapor deposition (MO-CVD) are investigated. Various forms of disorder in QWH's are studied and compared by employing photoluminescence techniques.","abstract_html":"The effects of disorder on the luminescence and laser properties of Al(,x)Ga(,1-x)As-GaAs (or AlAs-GaAs) quantum-well heterostructures (QWH's) grown by metalorganic chemical vapor deposition (MO-CVD) are investigated. Various forms of disorder in QWH's are studied and compared by employing photoluminescence techniques.","abstract_has_math":false,"creators":["Laidig, Wyn Davis"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Physics","degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2015,"date_issued":"2015-05-13T15:41:29Z","date_published":"2015-05-13T15:41:29Z","updated_at":"2026-07-22T22:26:10Z","subjects":["Physics, Condensed Matter"],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["(UMI)AAI8203510"],"render_values":[{"text":"(UMI)AAI8203510","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/77338","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Laidig, Wyn Davis"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2015-05-13T15:41:29Z","10000-01-01","1981"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Physics"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Physics, Condensed Matter"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/77338","(UMI)AAI8203510"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The effects of disorder on the luminescence and laser properties of Al(,x)Ga(,1-x)As-GaAs (or AlAs-GaAs) quantum-well heterostructures (QWH's) grown by metalorganic chemical vapor deposition (MO-CVD) are investigated. Various forms of disorder in QWH's are studied and compared by employing photoluminescence techniques.","It is possible to disorder a QWH by thermal annealing at temperatures (800-1000(DEGREES)C) significantly higher than the crystal growth temperature. A proper choice of annealing time and temperature results in the interdiffusion of the thin GaAs and AlAs (or Al(,x)Ga(,1-x)As) layers in the QWH active region and forms a compositionally disordered Al(,x)Ga(,1-x)As active layer. This resulting double heterostructure may be either direct or indirect band gap depending on the specific sizes and compositions of the "as-grown" layers. Additional information concerning phonon effects in QWH's may be gained by annealing a QWH with an active region of one large GaAs layer coupled to an array of smaller layers. Recombination from the "as-grown" QWH is phonon-assisted, however, after the smaller layers are damaged by thermally-induced interdiffusion, emission is no longer phonon-assisted but characteristic of a single layer of GaAs.","Similar effects are seen in Zn-diffused QWH's. It is shown that even at relatively low temperatures (500-600(DEGREES)C), well below the crystal growth temperature, conventional Zn diffusion greatly enhances the Al-Ga interdiffusion process. Thus, AlAs (or Al(,x)Ga(,1-x)As) and GaAs layers may be converted to single-crystal homogeneous Al(,x)Ga(,1-x)As that is now doped p-type. Since the Zn diffusions may be masked by a thin layer of Si(,3)N(,4), it is possible to disorder only selected portions of a QWH, leaving the remaining areas in their "as-grown" form. An example of a red superlattice laser integrated in a yellow indirect-band-gap Al(,x)Ga(,1-x)As cavity is shown, establishing a basis for monolithically integrating QWH lasers (and other devices) on an Al(,x)Ga(,1-x)As optoelectronic "chip".","Another form of disorder is that of clustering in a ternary alloy such as Al(,x)Ga(,1-x)As. Although alloy clustering may be affected by many variables, it must be regarded at least to some extent as intrinsic to a ternary alloy. Data are presented that show QWH luminescence to be sensitive to alloy clustering when Al(,x)Ga(,1-x)As barrier sizes approach the maximum cluster size. It is shown that alloy clustering and its associated problems (spectral broadening and lower-energy laser emission) are avoided by substituting AlAs for Al(,x)Ga(,1-x)As in the QWH active region. This allows fluctuations in layer thicknesses to be as small as (TURN)5 (ANGSTROM) and in addition results in high-energy (visible) laser operation (TURN)400 meV above E(,g)(GaAs) at room temperature.","Made available in DSpace on 2015-05-13T15:41:29Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 8203510.PDF: 3237028 bytes, checksum: 99b057c482c484193bfcca1aa29f2916 (MD5) Previous issue date: 1981","Embargo set by: Seth Robbins for item 78549 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","130 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1981."]},{"key":"dc:title","label":"Title","values":["Disorder Effects in Aluminum-Gallium - Arsenide Quantum-Well Heterostructures"]}]}],"canonical_facts":{"dc:creator":["Laidig, Wyn Davis"],"dc:date":["2015-05-13T15:41:29Z","10000-01-01","1981"],"dc:description":["The effects of disorder on the luminescence and laser properties of Al(,x)Ga(,1-x)As-GaAs (or AlAs-GaAs) quantum-well heterostructures (QWH's) grown by metalorganic chemical vapor deposition (MO-CVD) are investigated. Various forms of disorder in QWH's are studied and compared by employing photoluminescence techniques.","It is possible to disorder a QWH by thermal annealing at temperatures (800-1000(DEGREES)C) significantly higher than the crystal growth temperature. A proper choice of annealing time and temperature results in the interdiffusion of the thin GaAs and AlAs (or Al(,x)Ga(,1-x)As) layers in the QWH active region and forms a compositionally disordered Al(,x)Ga(,1-x)As active layer. This resulting double heterostructure may be either direct or indirect band gap depending on the specific sizes and compositions of the "as-grown" layers. Additional information concerning phonon effects in QWH's may be gained by annealing a QWH with an active region of one large GaAs layer coupled to an array of smaller layers. Recombination from the "as-grown" QWH is phonon-assisted, however, after the smaller layers are damaged by thermally-induced interdiffusion, emission is no longer phonon-assisted but characteristic of a single layer of GaAs.","Similar effects are seen in Zn-diffused QWH's. It is shown that even at relatively low temperatures (500-600(DEGREES)C), well below the crystal growth temperature, conventional Zn diffusion greatly enhances the Al-Ga interdiffusion process. Thus, AlAs (or Al(,x)Ga(,1-x)As) and GaAs layers may be converted to single-crystal homogeneous Al(,x)Ga(,1-x)As that is now doped p-type. Since the Zn diffusions may be masked by a thin layer of Si(,3)N(,4), it is possible to disorder only selected portions of a QWH, leaving the remaining areas in their "as-grown" form. An example of a red superlattice laser integrated in a yellow indirect-band-gap Al(,x)Ga(,1-x)As cavity is shown, establishing a basis for monolithically integrating QWH lasers (and other devices) on an Al(,x)Ga(,1-x)As optoelectronic "chip".","Another form of disorder is that of clustering in a ternary alloy such as Al(,x)Ga(,1-x)As. Although alloy clustering may be affected by many variables, it must be regarded at least to some extent as intrinsic to a ternary alloy. Data are presented that show QWH luminescence to be sensitive to alloy clustering when Al(,x)Ga(,1-x)As barrier sizes approach the maximum cluster size. It is shown that alloy clustering and its associated problems (spectral broadening and lower-energy laser emission) are avoided by substituting AlAs for Al(,x)Ga(,1-x)As in the QWH active region. This allows fluctuations in layer thicknesses to be as small as (TURN)5 (ANGSTROM) and in addition results in high-energy (visible) laser operation (TURN)400 meV above E(,g)(GaAs) at room temperature.","Made available in DSpace on 2015-05-13T15:41:29Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 8203510.PDF: 3237028 bytes, checksum: 99b057c482c484193bfcca1aa29f2916 (MD5) Previous issue date: 1981","Embargo set by: Seth Robbins for item 78549 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","130 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1981."],"dc:identifier":["http://hdl.handle.net/2142/77338","(UMI)AAI8203510"],"dc:language":["eng"],"dc:subject":["Physics, Condensed Matter"],"dc:title":["Disorder Effects in Aluminum-Gallium - Arsenide Quantum-Well Heterostructures"],"dc:type":["text"],"thesis:degree_discipline":["Physics"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:26:10Z"}