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Amorphous selenium (a-Se) avalanche photodetector for applications in positron emission tomography (PET)

dc.contributor.advisorReznik, Alla
dc.contributor.authorBubon, Oleksandr
dc.date.accessioned2012-11-11T03:21:09Z
dc.date.available2012-11-11T03:21:09Z
dc.date.created2011
dc.date.issued2011
dc.identifier.urihttp://knowledgecommons.lakeheadu.ca/handle/2453/296
dc.description.abstractAlthough avalanche amorphous selenium (a-Se) is a very promising photoconductor for a variety of imaging applications, it is currently restricted to applications with electron beam readout. This is performed with a vacuum pick-up tube called a High-gain Avalanche Rushing Photoconductor (HARP) Vidicon. The electron beam readout is compatible with high definition television (HDTV) applications, but for use in medical imaging devices it should be replaced by an solid-state electronic readout with a two-dimensional array of metal pixel electrodes. However, due to the high electric field required for avalanche multiplication, it is a technological challenge to avoid dielectric breakdown at the edges, where electric field experiences local enhancement. We show that this problem can be overcome by the use of a Resistive Interface Layer (RIL) deposited between the uniform a-Se layer and the array of metal electrodes. By detailed analysis of charge transport properties we demonstrate that RIL enables stable avalanche operation in a-Se photoconductor without degradation in charge transport or avalanche multiplication gain. Our results showed that a stable gain of 200 is reached at 104 V/μm for a 15-μm thick a-Se layer, which is the maximum theoretical gain for this thickness. We conclude that RIL is an enabling technology for practical implementation of solid-state avalanche a-Se image sensors.en_US
dc.language.isoen_USen_US
dc.subjectAvalanche amorphous selenium (a-Se)en_US
dc.subjectPositron Emission Tomography (PET)en_US
dc.subjectPositron emissionen_US
dc.subjectRadioactive decayen_US
dc.subjectAnnihilationen_US
dc.subjectPositron rangeen_US
dc.titleAmorphous selenium (a-Se) avalanche photodetector for applications in positron emission tomography (PET)en_US
dc.typeThesisen_US
etd.degree.nameMaster of Scienceen_US
etd.degree.levelMasteren_US
etd.degree.disciplinePhysicsen_US
etd.degree.grantorLakehead Universityen_US
dc.contributor.committeememberDas, Gautam
dc.contributor.committeememberRowlands, John


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