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dc.contributor.advisorScolfaro, Luisa M.
dc.contributor.authorShook, James A. ( Orcid Icon 0000-0003-4147-7537 )
dc.date.accessioned2018-08-06T15:11:14Z
dc.date.available2018-08-06T15:11:14Z
dc.date.issued2018-07-19
dc.identifier.urihttps://digital.library.txstate.edu/handle/10877/7371
dc.description.abstractThe need for well understood, commercially available p-type transparent conducting oxides for incorporation into basic transparent semiconducting devices alongside their already well understood and available n-type counterparts for application in technologies such as solar cells and capacitive touchscreens motivates this first principles study on the effects of Cu and O vacancies and Mg doping on the intrinsically poor p-type character of CuAlO2, AgAlO2, CuCrO2, and AgCrO2. Density functional theory based calculations using the projector augmented-wave functions along with the generalized gradient approximation to the exchange and correlation energy as implemented by the Vienna Ab Initio Simulation Package are used to study the total crystal energy of the three known polymorphs of CuAlO2 and AgAlO2 in order to determine the most stable polymorph in the ground state. Additionally, three simple magnetic configurations are considered for CuCrO2 and AgCrO2 in the context of total energy of the ground state for the purpose of choosing a specific polymorph and magnetic configuration to be the framework within which the doped and defect systems will be studied. Different functional approaches to the exchange and correlation energies are also considered in order to accurately reproduce the structural properties and the band gap. The 2H delafossite polymorph is determined to be one of the most stable polymorphs and is the focus of this work as it is the least studied of the delafossites. The simple antiferromagnetic configuration is chosen to model magnetic effects in CuCrO2 and AgCrO2 due to it having one of the lowest ground state total energies and also containing the most semiconductor like behavior of the magnetic configurations considered. A 2x2x2 supercell scheme is employed to model 6.25% Cu and Ag vacancies, 3.13% O vacancies, and 6.25% Mg-doping replacing Al and Cr, from which structural properties, electronic properties, hole effective masses, and optical properties are obtained and compared to the pristine crystal in order to offer predictions on the effectiveness of the mentioned native defects and dopant on increasing the conductivity and maintaining transparency in all transparent conducting oxides studied in this work. Comparisons between the results obtained in this work and previous experimental and other theoretical results are made, when available. Many of the properties predicted here are immediately testable via experimentation.
dc.formatText
dc.format.extent151 pages
dc.format.medium1 file (.pdf)
dc.language.isoen_US
dc.subjectTransparent Conducting Oxides
dc.subjectPhysics
dc.subjectDensity Functional Theory
dc.subjectCrystal Structure
dc.subjectElectronic Structure
dc.subjectHole Effective Masses
dc.subjectOptical Properties
dc.subjectDefects
dc.subjectDopants
dc.subject.lcshNanostructured materialsen_US
dc.subject.lcshMetal oxide semiconductorsen_US
dc.subject.lcshOxide coatingen_US
dc.titleFirst Principles Study on the Effects of Vacancies and Mg Doping on the Physical Properties of CuAlO2, AgAlO2, CuCrO2, and AgCrO2 Transparent Conductor Oxides
txstate.documenttypeThesis
dc.contributor.committeeMemberTheodoropoulou, Nikoleta
dc.contributor.committeeMemberZakhidov, Alex
thesis.degree.departmentPhysics
thesis.degree.disciplinePhysics
thesis.degree.grantorTexas State University
thesis.degree.levelMasters
thesis.degree.nameMaster of Science
txstate.departmentPhysics


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