Cross-Sectional Scanning Tunneling Microscopy Studies of In 1-xGax Sb/InAs Quantum Dots

This thesis focuses on the characterization of In 0,4 Ga 0,6 Sb/InAs and InSb/InAs quantum dots using Cross-Sectional Scanning Tunneling Microscopy (X-STM). Quantum dots (QDs) are small and spatially confined semiconductor nanostructures with a size-dependent band gap. This property makes them very...

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Main Authors: Reuterskiöld Hedlund, Carl, Ernerheim Jokumsen, Christopher
Format: Others
Language:English
Published: KTH, Skolan för informations- och kommunikationsteknik (ICT) 2012
Online Access:http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-101481
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spelling ndltd-UPSALLA1-oai-DiVA.org-kth-1014812013-01-08T13:52:37ZCross-Sectional Scanning Tunneling Microscopy Studies of In 1-xGax Sb/InAs Quantum DotsengReuterskiöld Hedlund, CarlErnerheim Jokumsen, ChristopherKTH, Skolan för informations- och kommunikationsteknik (ICT)KTH, Skolan för informations- och kommunikationsteknik (ICT)2012This thesis focuses on the characterization of In 0,4 Ga 0,6 Sb/InAs and InSb/InAs quantum dots using Cross-Sectional Scanning Tunneling Microscopy (X-STM). Quantum dots (QDs) are small and spatially confined semiconductor nanostructures with a size-dependent band gap. This property makes them very attractive for devices such as sensors, solar cells and lasers. The QDs analyzed in this thesis were grown using Metal-Organic Vapor Phase Epitaxy (MOVPE) and are meant to be utilized in long wavelength infrared (LWIR) (~8μm) detectors. To study buried QDs by X-STM, the sample has to be cleaved and measured in Ultra High Vacuum (UHV). In order to do this, a cleaving apparatus was built and installed on an STM system. A sample preparation methodology was worked out in order to make the samples ready for cleaving. An easy method for finding the QDs with the X-STM was also developed. Measurements resulted in a number of atomically resolved images, revealing the QD layer morphology. Furthermore, larger images were captured in order to study growth defects. Because of the high dot density, at low resolution the QDs were perceived as quantum wells. It was only at atomic resolution that QDs could be resolved. The observed dot sizes ranged between ~3 nm (InSb) and ~8 nm (In 0,4 Ga 0,6 Sb) in diameter. Student thesisinfo:eu-repo/semantics/bachelorThesistexthttp://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-101481Trita-ICT-EX ; 2012:169application/pdfinfo:eu-repo/semantics/openAccess
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language English
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description This thesis focuses on the characterization of In 0,4 Ga 0,6 Sb/InAs and InSb/InAs quantum dots using Cross-Sectional Scanning Tunneling Microscopy (X-STM). Quantum dots (QDs) are small and spatially confined semiconductor nanostructures with a size-dependent band gap. This property makes them very attractive for devices such as sensors, solar cells and lasers. The QDs analyzed in this thesis were grown using Metal-Organic Vapor Phase Epitaxy (MOVPE) and are meant to be utilized in long wavelength infrared (LWIR) (~8μm) detectors. To study buried QDs by X-STM, the sample has to be cleaved and measured in Ultra High Vacuum (UHV). In order to do this, a cleaving apparatus was built and installed on an STM system. A sample preparation methodology was worked out in order to make the samples ready for cleaving. An easy method for finding the QDs with the X-STM was also developed. Measurements resulted in a number of atomically resolved images, revealing the QD layer morphology. Furthermore, larger images were captured in order to study growth defects. Because of the high dot density, at low resolution the QDs were perceived as quantum wells. It was only at atomic resolution that QDs could be resolved. The observed dot sizes ranged between ~3 nm (InSb) and ~8 nm (In 0,4 Ga 0,6 Sb) in diameter.
author Reuterskiöld Hedlund, Carl
Ernerheim Jokumsen, Christopher
spellingShingle Reuterskiöld Hedlund, Carl
Ernerheim Jokumsen, Christopher
Cross-Sectional Scanning Tunneling Microscopy Studies of In 1-xGax Sb/InAs Quantum Dots
author_facet Reuterskiöld Hedlund, Carl
Ernerheim Jokumsen, Christopher
author_sort Reuterskiöld Hedlund, Carl
title Cross-Sectional Scanning Tunneling Microscopy Studies of In 1-xGax Sb/InAs Quantum Dots
title_short Cross-Sectional Scanning Tunneling Microscopy Studies of In 1-xGax Sb/InAs Quantum Dots
title_full Cross-Sectional Scanning Tunneling Microscopy Studies of In 1-xGax Sb/InAs Quantum Dots
title_fullStr Cross-Sectional Scanning Tunneling Microscopy Studies of In 1-xGax Sb/InAs Quantum Dots
title_full_unstemmed Cross-Sectional Scanning Tunneling Microscopy Studies of In 1-xGax Sb/InAs Quantum Dots
title_sort cross-sectional scanning tunneling microscopy studies of in 1-xgax sb/inas quantum dots
publisher KTH, Skolan för informations- och kommunikationsteknik (ICT)
publishDate 2012
url http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-101481
work_keys_str_mv AT reuterskioldhedlundcarl crosssectionalscanningtunnelingmicroscopystudiesofin1xgaxsbinasquantumdots
AT ernerheimjokumsenchristopher crosssectionalscanningtunnelingmicroscopystudiesofin1xgaxsbinasquantumdots
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