Thesis
Electronic transport across perovskite-based heterojunctions
Master of Science (M.S.), Drexel University
01 Jun 2015
DOI:
https://doi.org/10.17918/etd-6533
Abstract
The ever-growing processing power of electronic devices is limited by the speed of miniaturization, increasing in leaps and bounds as technology allows. Researchers have been investigating novel electronic materials that offer multiple switching properties that may enable additional processing paths. One such material group with the potential to achieve this goal is perovskite oxides. However, limited understanding of electronic transport across perovskite junctions remain an obstacle to device integration. In this thesis, the electronic behavior of metal/oxide and oxide/oxide heterojunctions was systematically studied as a function of oxide composition and temperature. The behavior of Ag/L_[1-x]S_xFO (x = 0.75, 0.45, 0.20) junctions were explored, and determined to have rectifying properties rather than a simple Ohmic character. This thesis revealed evidence of a difference in specific contact resistivity for the Ag / L_[1-x]S_xFO heterojunction based on bias and composition (x). Different resistances were measured under positive and negative bias when contact area varied and direction of current flow switched. When L_[1-x]S_xFO was epitaxially grown on niobium-doped SrTiO₃ substrates, a p-n junction was created. These devices consisted of silver paint contacts on either side of an STNO / L_[1-x]S_xFO (x = 0.75, 0.50, 0.25) wafer. In the full devices, slight directional preference was observed in all samples. The x = 0.50 device showed better conduction than either of the other two samples. When the contact resistances were extrapolated and removed from the total resistance of each device, behavior of the p-n heterojunction was isolated, allowing for the conduction to be analyzed within the context of existing heterojunction transport models. This thesis concluded that rectifying behavior was present at both heterojunctions, metal / oxide and oxide / oxide, providing direction for future studies of these devices.
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Details
- Title
- Electronic transport across perovskite-based heterojunctions
- Creators
- James F. Devine - DU
- Contributors
- Steven J. May (Advisor) - Drexel University (1970-)
- Awarding Institution
- Drexel University
- Degree Awarded
- Master of Science (M.S.)
- Publisher
- Drexel University; Philadelphia, Pennsylvania
- Resource Type
- Thesis
- Language
- English
- Academic Unit
- Materials (Science and) Engineering (Metallurgical Engineering) (1970-2026); College of Engineering (1970-2026); Drexel University
- Other Identifier
- 6533; 991014632553804721