Role of the Metal/Dielectric Interface in Dielectric Degradation and Breakdown
Abstract
A fundamental understanding of the role of interfaces, defects, microstructure, and thecharge transport phenomena is critical to developing a mechanistic understanding of degradationand breakdown processes in dielectric capacitors used in extreme environments. With thisunderstanding, the life-time of dielectric capacitors may be prolonged through mitigation ofundesirable voltage-induced resistance changes. The main objective of this research program is todevelop a fundamental understanding of the roles that interfaces and the attendant interaction ofpoint defects play in dielectric degradation and breakdown in extreme environments. Toaccomplish this, we will develop and implement a hierarchical multi-scale simulation framework.This framework integrates quantitative predictions from density functional theory (DFT) usingstate-of-the-art hybrid exchange correlation functionals with two approaches that capture differentlength and time scales. The first tool couples DFT together with solutions of the Poisson-Schrödinger equation (PSE). The PSE has been widely used in device simulations to capture theinfluence of field, interfaces, contacts, surfaces and dopants. Here we will integrate with the abovemethods the defect formation energy data set and solutions to charge balance equations to betterunderstand the space charge development near metal dielectric interfaces. DFT calculations willalso be implemented to understand the migration of charged point defects within the bulk and nearhighly symmetric grain boundaries. These results will be used to understand experiment and toinform phase-field methods implemented by Chen. We will improve the mesoscale dielectricdegradation model by refining the charge injection description.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 09, 2018
- Source ID
- FA95501710318
Entities
People
- Douglas L Irving
Organizations
- Air Force Office of Scientific Research
- North Carolina State University
- United States Air Force