Organic Opto-Electronic Devices for Data Storage and Solid-State Lighting

Persistent Link:
http://hdl.handle.net/10150/193770
Title:
Organic Opto-Electronic Devices for Data Storage and Solid-State Lighting
Author:
Lauters, Michael E
Issue Date:
2006
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Metal/organic/indium tin oxide (ITO) structures, including OLEDs, are demonstrated to contain multiple nonvolatile conductance states that can be programmed by the application of an external bias above a certain threshold voltage (Vth). These conductance states are stable and in turn can be probed by the use of a bias lower in value than Vth. The unbiased retention time of states is greater than several weeks, and more than 48,000 write-read-rewrite-read cycles have been performed with minimal degradation. It is found that the programming of a continuum of conductance states is possible, and techniques to do so are outlined. The electrical conductivity of the highest and lowest states can differ by six orders of magnitude. Switching speeds below 50 ns are shown, resulting in an energy requirement of about 100 pJ to switch from one conductance state to another. The memory phenomenon is shown to be influenced by the active layer thickness and anode/surface roughness while temperature dependence is limited. The electrical characteristics of these devices are consistent with metal diffusion or filament phenomena found in metal-insulator-metal structures, suggesting a possible mechanism by which the states are stored.Electroluminescent devices employing several new organic-inorganic lumophore-functionalized macromolecules are presented. In this study, macromolecules incorporating several lumophores covalently bonded to the vertices of a cubical core structure based on Polyhedral Oligomeric Silsesquioxane (POSS) in multiple configurations are implemented as light-emitting centers. The hole-transporting polymer poly(N-vinylcarbazole) (PVK) and electron-transporting additive 2-(4-biphenylyl)-5-(4-tert-butylphenyl)1,3,4-oxadiazole (PBD) are used as a two-part host to enhance the carrier transport in these simple solution-processed single-layer devices. A study of energy transfer in several systems is carried out to understand the requirements needed to create white-light emission from a single macromolecule. A single macromolecule incorporating twenty-one blue and one yellow lumophore is shown to exhibit field-independent stable white-light electroluminescence with Commission Internationale de l'Eclairage (CIE) coordinates of (0.31, 0.37). An external quantum efficiency of 0.55 percent and a maximum brightness of 1600 cd/m2 are attained with simple solution-processed single-layer devices. High solubility and ease of purification give these macromolecule white-light emitters advantages over their small molecule and polymeric type counterparts.
Type:
text; Electronic Dissertation
Keywords:
Organic Light Emitting Diode; Memory; Conductance States; MIM; Macromolecule
Degree Name:
PhD
Degree Level:
doctoral
Degree Program:
Optical Sciences; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Sarid, Dror
Committee Chair:
Sarid, Dror

Full metadata record

DC FieldValue Language
dc.language.isoENen_US
dc.titleOrganic Opto-Electronic Devices for Data Storage and Solid-State Lightingen_US
dc.creatorLauters, Michael Een_US
dc.contributor.authorLauters, Michael Een_US
dc.date.issued2006en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractMetal/organic/indium tin oxide (ITO) structures, including OLEDs, are demonstrated to contain multiple nonvolatile conductance states that can be programmed by the application of an external bias above a certain threshold voltage (Vth). These conductance states are stable and in turn can be probed by the use of a bias lower in value than Vth. The unbiased retention time of states is greater than several weeks, and more than 48,000 write-read-rewrite-read cycles have been performed with minimal degradation. It is found that the programming of a continuum of conductance states is possible, and techniques to do so are outlined. The electrical conductivity of the highest and lowest states can differ by six orders of magnitude. Switching speeds below 50 ns are shown, resulting in an energy requirement of about 100 pJ to switch from one conductance state to another. The memory phenomenon is shown to be influenced by the active layer thickness and anode/surface roughness while temperature dependence is limited. The electrical characteristics of these devices are consistent with metal diffusion or filament phenomena found in metal-insulator-metal structures, suggesting a possible mechanism by which the states are stored.Electroluminescent devices employing several new organic-inorganic lumophore-functionalized macromolecules are presented. In this study, macromolecules incorporating several lumophores covalently bonded to the vertices of a cubical core structure based on Polyhedral Oligomeric Silsesquioxane (POSS) in multiple configurations are implemented as light-emitting centers. The hole-transporting polymer poly(N-vinylcarbazole) (PVK) and electron-transporting additive 2-(4-biphenylyl)-5-(4-tert-butylphenyl)1,3,4-oxadiazole (PBD) are used as a two-part host to enhance the carrier transport in these simple solution-processed single-layer devices. A study of energy transfer in several systems is carried out to understand the requirements needed to create white-light emission from a single macromolecule. A single macromolecule incorporating twenty-one blue and one yellow lumophore is shown to exhibit field-independent stable white-light electroluminescence with Commission Internationale de l'Eclairage (CIE) coordinates of (0.31, 0.37). An external quantum efficiency of 0.55 percent and a maximum brightness of 1600 cd/m2 are attained with simple solution-processed single-layer devices. High solubility and ease of purification give these macromolecule white-light emitters advantages over their small molecule and polymeric type counterparts.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectOrganic Light Emitting Diodeen_US
dc.subjectMemoryen_US
dc.subjectConductance Statesen_US
dc.subjectMIMen_US
dc.subjectMacromoleculeen_US
thesis.degree.namePhDen_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineOptical Sciencesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorSarid, Droren_US
dc.contributor.chairSarid, Droren_US
dc.contributor.committeememberJabbour, Ghassanen_US
dc.contributor.committeememberMilster, Thomasen_US
dc.identifier.proquest1899en_US
dc.identifier.oclc659746464en_US
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