{"id":{"repo_id":"cape-town","oai_identifier":"oai:open.uct.ac.za:11427/6995"},"canonical_url":"https://search.dev.ndltd.org/etd/cape-town/oai:open.uct.ac.za:11427/6995","repository":{"repo_id":"cape-town","name":"University of Cape Town","base_url":"https://open.uct.ac.za/oai/request"},"display":{"title":"Growth temperature and microstructural differences in hydrogenated amorphous silicon deposited on glass substrates","abstract":"Hydrogenated amorphous silicon (a-Si:H) is an important thin film semiconductor with a wide variety of applications in microelectronics and optoelectronics. However, it is metastable and photodegrades after a moderate light illumination (Staebler-Wronski effect). The most stable material has been suggested to be at the edge of crystallinity with microcrystalline inclusions. Using a combination of positron annihilation and X-ray diffraction techniques, the microstructure of hydrogenated amorphous silicon grown by hot wire chemical vapour deposition on glass substrates at different substrate temperatures ranging between 300°C and 500 °C is examined. In previous studies the crystallisation was accompanied by a relaxation of defect structure with an increase in free volume at positron annihilation site. In this work, both techniques show a relaxation of the network with increasing growth temperature, leading to a higher degree of ordering, shorter bond lengths, and a reduction in the average size of defects in the material.","abstract_html":"Hydrogenated amorphous silicon (a-Si:H) is an important thin film semiconductor with a wide variety of applications in microelectronics and optoelectronics. However, it is metastable and photodegrades after a moderate light illumination (Staebler-Wronski effect). The most stable material has been suggested to be at the edge of crystallinity with microcrystalline inclusions. Using a combination of positron annihilation and X-ray diffraction techniques, the microstructure of hydrogenated amorphous silicon grown by hot wire chemical vapour deposition on glass substrates at different substrate temperatures ranging between 300°C and 500 °C is examined. In previous studies the crystallisation was accompanied by a relaxation of defect structure with an increase in free volume at positron annihilation site. In this work, both techniques show a relaxation of the network with increasing growth temperature, leading to a higher degree of ordering, shorter bond lengths, and a reduction in the average size of defects in the material.","abstract_has_math":false,"creators":["Minani, Evariste"],"institution":"Department of Physics","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Härting, Margit","Britton, David T"],"committee_chairs":[],"committee_members":[],"year":2002,"date_issued":"2002","date_published":"2002","updated_at":"2026-07-22T22:22:47Z","subjects":[],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/11427/6995","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Härting, Margit","Britton, David T"]},{"key":"dc:creator","label":"Author","values":["Minani, Evariste"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-09-08T14:27:37Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-09-08T14:27:37Z"]},{"key":"dc:date.issued","label":"Date","values":["2002"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["Department of Physics"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Cape Town"]},{"key":"dc:type","label":"Dc Type","values":["Master Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Masters"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["MSc"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/11427/6995"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Includes bibliography."]},{"key":"dc:description.abstract","label":"Abstract","values":["Hydrogenated amorphous silicon (a-Si:H) is an important thin film semiconductor with a wide variety of applications in microelectronics and optoelectronics. However, it is metastable and photodegrades after a moderate light illumination (Staebler-Wronski effect). The most stable material has been suggested to be at the edge of crystallinity with microcrystalline inclusions. Using a combination of positron annihilation and X-ray diffraction techniques, the microstructure of hydrogenated amorphous silicon grown by hot wire chemical vapour deposition on glass substrates at different substrate temperatures ranging between 300°C and 500 °C is examined. In previous studies the crystallisation was accompanied by a relaxation of defect structure with an increase in free volume at positron annihilation site. In this work, both techniques show a relaxation of the network with increasing growth temperature, leading to a higher degree of ordering, shorter bond lengths, and a reduction in the average size of defects in the material."]},{"key":"dc:title","label":"Title","values":["Growth temperature and microstructural differences in hydrogenated amorphous silicon deposited on glass substrates"]}]}],"canonical_facts":{"dc:contributor.advisor":["Härting, Margit","Britton, David T"],"dc:creator":["Minani, Evariste"],"dc:date.accessioned":["2014-09-08T14:27:37Z"],"dc:date.available":["2014-09-08T14:27:37Z"],"dc:date.issued":["2002"],"dc:description":["Includes bibliography."],"dc:description.abstract":["Hydrogenated amorphous silicon (a-Si:H) is an important thin film semiconductor with a wide variety of applications in microelectronics and optoelectronics. However, it is metastable and photodegrades after a moderate light illumination (Staebler-Wronski effect). The most stable material has been suggested to be at the edge of crystallinity with microcrystalline inclusions. Using a combination of positron annihilation and X-ray diffraction techniques, the microstructure of hydrogenated amorphous silicon grown by hot wire chemical vapour deposition on glass substrates at different substrate temperatures ranging between 300°C and 500 °C is examined. In previous studies the crystallisation was accompanied by a relaxation of defect structure with an increase in free volume at positron annihilation site. In this work, both techniques show a relaxation of the network with increasing growth temperature, leading to a higher degree of ordering, shorter bond lengths, and a reduction in the average size of defects in the material."],"dc:identifier.uri":["http://hdl.handle.net/11427/6995"],"dc:language.iso":["eng"],"dc:publisher.department":["Department of Physics"],"dc:publisher.institution":["University of Cape Town"],"dc:title":["Growth temperature and microstructural differences in hydrogenated amorphous silicon deposited on glass substrates"],"dc:type":["Master Thesis"],"dc:type.qualificationlevel":["Masters"],"dc:type.qualificationname":["MSc"]},"updated_at":"2026-07-22T22:22:47Z"}