{"id":{"repo_id":"vilnius","oai_identifier":"oai:vu.lt:elaba:210578936"},"canonical_url":"https://search.dev.ndltd.org/etd/vilnius/oai:vu.lt:elaba:210578936","repository":{"repo_id":"vilnius","name":"Vilnius University","base_url":"https://epublications.vu.lt/oai"},"display":{"title":"Ultravioletinės srities šviesos diodų žemadažnio triukšmo tyrimas /","abstract":"The aim of this work was to investigate low-frequency noise characteristics of UV LEDs, evaluate simultaneous cross-correlation coefficient between electrical and optical fluctuations and apply correlation method for InGaN-based LEDs. Two AlGaN-based LEDs (275 nm) and two InGaN-based LEDs (370 and 385 nm) were investigated. All investigated LEDs exhibited 1/f^α electrical and optical fluctuations while electrical generation-recombination noise with Lorentzian-type spectra were additionally observed in some current ranges of AlGaN-based LEDs. Shot noise was also observed in all optical spectra at higher frequencies. 1/f^α noise components of InGaN-based LEDs optical noise showed to be significantly more intense however the level of normalised optical noise was higher in AlGaN LEDs. Simultaneous cross-correlation coefficient (10 Hz – 20 kHz) measured close to zero in all current range for the first AlGaN-based LED and slightly negative for the second. InGaN-based LEDs exhibited higher correlation coefficients with peak values of ~63% and ~47% for each LED. Correlation method was used for InGaN-based diodes to investigate cross-correlation coefficients at its peak values which yielded that almost all observed low-frequency fluctuations of the first InGaN-based LED and approximately half of 1/f and 70% of 1/f^α fluctuations of the second InGaN-based LED are related with defects in active layer.","abstract_html":"The aim of this work was to investigate low-frequency noise characteristics of UV LEDs, evaluate simultaneous cross-correlation coefficient between electrical and optical fluctuations and apply correlation method for InGaN-based LEDs. Two AlGaN-based LEDs (275 nm) and two InGaN-based LEDs (370 and 385 nm) were investigated. All investigated LEDs exhibited 1/f^α electrical and optical fluctuations while electrical generation-recombination noise with Lorentzian-type spectra were additionally observed in some current ranges of AlGaN-based LEDs. Shot noise was also observed in all optical spectra at higher frequencies. 1/f^α noise components of InGaN-based LEDs optical noise showed to be significantly more intense however the level of normalised optical noise was higher in AlGaN LEDs. Simultaneous cross-correlation coefficient (10 Hz – 20 kHz) measured close to zero in all current range for the first AlGaN-based LED and slightly negative for the second. InGaN-based LEDs exhibited higher correlation coefficients with peak values of ~63% and ~47% for each LED. Correlation method was used for InGaN-based diodes to investigate cross-correlation coefficients at its peak values which yielded that almost all observed low-frequency fluctuations of the first InGaN-based LED and approximately half of 1/f and 70% of 1/f^α fluctuations of the second InGaN-based LED are related with defects in active layer.","abstract_has_math":false,"creators":["Pliaterytė, Ingrida,"],"institution":"Institutional Repository of Vilnius University","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2024,"date_issued":"2024","date_published":"2024","updated_at":"2026-07-24T05:55:48Z","subjects":[],"languages":["lit"],"rights":["info:eu-repo/semantics/openAccess"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://repository.vu.lt/VU:ELABAETD210578936&prefLang=en_US","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Pliaterytė, Ingrida,"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2024"]},{"key":"dc:publisher","label":"Institution","values":["Institutional Repository of Vilnius University"]},{"key":"dc:relation","label":"Dc Relation","values":["https://epublications.vu.lt/object/elaba:210578936/210578936.pdf"]},{"key":"dc:type","label":"Dc Type","values":["info:eu-repo/semantics/bachelorThesis"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["lit"]},{"key":"dc:rights","label":"Dc Rights","values":["info:eu-repo/semantics/openAccess"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://repository.vu.lt/VU:ELABAETD210578936&prefLang=en_US"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The aim of this work was to investigate low-frequency noise characteristics of UV LEDs, evaluate simultaneous cross-correlation coefficient between electrical and optical fluctuations and apply correlation method for InGaN-based LEDs. Two AlGaN-based LEDs (275 nm) and two InGaN-based LEDs (370 and 385 nm) were investigated. All investigated LEDs exhibited 1/f^α electrical and optical fluctuations while electrical generation-recombination noise with Lorentzian-type spectra were additionally observed in some current ranges of AlGaN-based LEDs. Shot noise was also observed in all optical spectra at higher frequencies. 1/f^α noise components of InGaN-based LEDs optical noise showed to be significantly more intense however the level of normalised optical noise was higher in AlGaN LEDs. Simultaneous cross-correlation coefficient (10 Hz – 20 kHz) measured close to zero in all current range for the first AlGaN-based LED and slightly negative for the second. InGaN-based LEDs exhibited higher correlation coefficients with peak values of ~63% and ~47% for each LED. Correlation method was used for InGaN-based diodes to investigate cross-correlation coefficients at its peak values which yielded that almost all observed low-frequency fluctuations of the first InGaN-based LED and approximately half of 1/f and 70% of 1/f^α fluctuations of the second InGaN-based LED are related with defects in active layer."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Ultravioletinės srities šviesos diodų žemadažnio triukšmo tyrimas /","Low-frequency noise investigation of ultraviolet light-emitting diodes."]}]}],"canonical_facts":{"dc:creator":["Pliaterytė, Ingrida,"],"dc:date":["2024"],"dc:description":["The aim of this work was to investigate low-frequency noise characteristics of UV LEDs, evaluate simultaneous cross-correlation coefficient between electrical and optical fluctuations and apply correlation method for InGaN-based LEDs. Two AlGaN-based LEDs (275 nm) and two InGaN-based LEDs (370 and 385 nm) were investigated. All investigated LEDs exhibited 1/f^α electrical and optical fluctuations while electrical generation-recombination noise with Lorentzian-type spectra were additionally observed in some current ranges of AlGaN-based LEDs. Shot noise was also observed in all optical spectra at higher frequencies. 1/f^α noise components of InGaN-based LEDs optical noise showed to be significantly more intense however the level of normalised optical noise was higher in AlGaN LEDs. Simultaneous cross-correlation coefficient (10 Hz – 20 kHz) measured close to zero in all current range for the first AlGaN-based LED and slightly negative for the second. InGaN-based LEDs exhibited higher correlation coefficients with peak values of ~63% and ~47% for each LED. Correlation method was used for InGaN-based diodes to investigate cross-correlation coefficients at its peak values which yielded that almost all observed low-frequency fluctuations of the first InGaN-based LED and approximately half of 1/f and 70% of 1/f^α fluctuations of the second InGaN-based LED are related with defects in active layer."],"dc:format":["application/pdf"],"dc:identifier":["https://repository.vu.lt/VU:ELABAETD210578936&prefLang=en_US"],"dc:language":["lit"],"dc:publisher":["Institutional Repository of Vilnius University"],"dc:relation":["https://epublications.vu.lt/object/elaba:210578936/210578936.pdf"],"dc:rights":["info:eu-repo/semantics/openAccess"],"dc:title":["Ultravioletinės srities šviesos diodų žemadažnio triukšmo tyrimas /","Low-frequency noise investigation of ultraviolet light-emitting diodes."],"dc:type":["info:eu-repo/semantics/bachelorThesis"]},"updated_at":"2026-07-24T05:55:48Z"}