Co-doping Perovskite Dielectrics for Higher Reliability under Extreme Voltage and Temperature Conditions
Abstract
The research program addresses compositional design strategies for improving the lifetime and breakdown strength of perovskite dielectrics by simultaneously limiting electronic conductivity and electromigration of oxygen vacancies. The strategy to improve dielectric reliability is to use a co-doping strategy with transition-metal and rare earth cations to control the Fermi level over broad oxygen activity ranges, overcoming the background trace impurities that are a consequence of the purification limits of metal-oxide materials used in capacitor manufacturing. Over the course of the program, we explored co-doping strategies to control the electronic and ionic conductivity of BaTiO3. A range of compositions have been fabricated, evaluating the Mn:Y or V:Y ratio as well as the Ba:Ti ratio, which can be utilized to push the amphoteric Y dopant onto either the Ba or Ti sublattice. The conductivities are measured as a function of temperature via impedance spectroscopy, and these data are utilized to guide the development of canonical defect chemistry measurements. Another effort is focused on understanding the conductivity of grain boundaries in these co-doped systems. The specific grain boundary resistances are extracted from impedance spectroscopy measurements and indicate the presence of a grain boundary potential barrier. In parallel, we are using transmission electron microscopy to measure the electric fields (and hence potential) at the grain boundaries to compare to the impedance-based measurements. These experimental studies are intended to provide fundamental information about doping strategies in dielectric materials.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 03, 2024
- Accession Number
- AD1231160
Entities
People
- Douglas L Irving
- Elizabeth C Dickey
Organizations
- North Carolina State University