{"id":{"repo_id":"mit","oai_identifier":"oai:dspace.mit.edu:1721.1/114089"},"canonical_url":"https://search.dev.ndltd.org/etd/mit/oai:dspace.mit.edu:1721.1/114089","repository":{"repo_id":"mit","name":"MIT","base_url":"https://dspace.mit.edu/oai/request"},"display":{"title":"Optical absorption of bismuth silicon oxide (Bi₁₂SiO₂₀) crystals","abstract":"The purpose of this work is to characterize the optical absorption in bismuth silicon oxide (Bi₁₂SiO₂₀) crystals grown using the Bridgman technique and to identify electronic transitions responsible for absorption. Optical measurements were taken in the range of 0.4 - 11 pm at 300 K and 77 K using a spectrometer. The results show that near the band edge, there is evidence of indirect transitions at 2.3 eV and excition transitions at 1.8 eV. Low temperature measurements revealed peaks of free carrier absorption in the visible light range at 1.7 eV and 2.1 eV. Illuminated samples at low temperature revealed empty donor levels in the visible range at 1.6-1.9 eV and 2.1 eV, indicating the presence of the photochromic effect and photorefractivity.","abstract_html":"The purpose of this work is to characterize the optical absorption in bismuth silicon oxide (Bi₁₂SiO₂₀) crystals grown using the Bridgman technique and to identify electronic transitions responsible for absorption. Optical measurements were taken in the range of 0.4 - 11 pm at 300 K and 77 K using a spectrometer. The results show that near the band edge, there is evidence of indirect transitions at 2.3 eV and excition transitions at 1.8 eV. Low temperature measurements revealed peaks of free carrier absorption in the visible light range at 1.7 eV and 2.1 eV. Illuminated samples at low temperature revealed empty donor levels in the visible range at 1.6-1.9 eV and 2.1 eV, indicating the presence of the photochromic effect and photorefractivity.","abstract_has_math":false,"creators":["Lee, Grace W. (Grace Wang)"],"institution":"Massachusetts Institute of Technology","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":"Massachusetts Institute of Technology. Department of Materials Science and Engineering.","school":null,"contributors":[],"advisors":["August F. Witt."],"committee_chairs":[],"committee_members":[],"year":2001,"date_issued":"2001","date_published":"2001","updated_at":"2026-07-22T22:21:10Z","subjects":["Materials Science and Engineering."],"languages":["eng"],"rights":["MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission."],"rights_urls":["http://dspace.mit.edu/handle/1721.1/7582"],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/1721.1/114089","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["August F. Witt."]},{"key":"dc:contributor.department","label":"Department","values":["Massachusetts Institute of Technology. Department of Materials Science and Engineering."]},{"key":"dc:contributor.other","label":"Dc Contributor Other","values":["Massachusetts Institute of Technology. Department of Materials Science and Engineering."]},{"key":"dc:creator","label":"Author","values":["Lee, Grace W. (Grace Wang)"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2018-03-12T19:29:25Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2018-03-12T19:29:25Z"]},{"key":"dc:date.issued","label":"Date","values":["2001"]},{"key":"dc:publisher","label":"Institution","values":["Massachusetts Institute of Technology"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Materials Science and Engineering."]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission."]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://dspace.mit.edu/handle/1721.1/7582"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/1721.1/114089"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Thesis: S.B., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2001.","Cataloged from PDF version of thesis.","Includes bibliographical references (page 23)."]},{"key":"dc:description.abstract","label":"Abstract","values":["The purpose of this work is to characterize the optical absorption in bismuth silicon oxide (Bi₁₂SiO₂₀) crystals grown using the Bridgman technique and to identify electronic transitions responsible for absorption. Optical measurements were taken in the range of 0.4 - 11 pm at 300 K and 77 K using a spectrometer. The results show that near the band edge, there is evidence of indirect transitions at 2.3 eV and excition transitions at 1.8 eV. Low temperature measurements revealed peaks of free carrier absorption in the visible light range at 1.7 eV and 2.1 eV. Illuminated samples at low temperature revealed empty donor levels in the visible range at 1.6-1.9 eV and 2.1 eV, indicating the presence of the photochromic effect and photorefractivity."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["S.B."]},{"key":"dc:title","label":"Title","values":["Optical absorption of bismuth silicon oxide (Bi₁₂SiO₂₀) crystals"]}]}],"canonical_facts":{"dc:contributor.advisor":["August F. Witt."],"dc:contributor.department":["Massachusetts Institute of Technology. Department of Materials Science and Engineering."],"dc:contributor.other":["Massachusetts Institute of Technology. Department of Materials Science and Engineering."],"dc:creator":["Lee, Grace W. (Grace Wang)"],"dc:date.accessioned":["2018-03-12T19:29:25Z"],"dc:date.available":["2018-03-12T19:29:25Z"],"dc:date.issued":["2001"],"dc:description":["Thesis: S.B., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2001.","Cataloged from PDF version of thesis.","Includes bibliographical references (page 23)."],"dc:description.abstract":["The purpose of this work is to characterize the optical absorption in bismuth silicon oxide (Bi₁₂SiO₂₀) crystals grown using the Bridgman technique and to identify electronic transitions responsible for absorption. Optical measurements were taken in the range of 0.4 - 11 pm at 300 K and 77 K using a spectrometer. The results show that near the band edge, there is evidence of indirect transitions at 2.3 eV and excition transitions at 1.8 eV. Low temperature measurements revealed peaks of free carrier absorption in the visible light range at 1.7 eV and 2.1 eV. Illuminated samples at low temperature revealed empty donor levels in the visible range at 1.6-1.9 eV and 2.1 eV, indicating the presence of the photochromic effect and photorefractivity."],"dc:description.degree":["S.B."],"dc:identifier.uri":["http://hdl.handle.net/1721.1/114089"],"dc:language.iso":["eng"],"dc:publisher":["Massachusetts Institute of Technology"],"dc:rights":["MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission."],"dc:rights.uri":["http://dspace.mit.edu/handle/1721.1/7582"],"dc:subject":["Materials Science and Engineering."],"dc:title":["Optical absorption of bismuth silicon oxide (Bi₁₂SiO₂₀) crystals"],"dc:type":["Thesis"]},"updated_at":"2026-07-22T22:21:10Z"}