Project title: Theory and simulation of charge injection at metal-polymer interfaces
Supervisors: Prof Arash Mostofi and Dr Mikael Unge
High voltage direct current (HVDC) technology is widely used in long-distance power transmission. One of the key scientific and technological challenges associated with insulation material for HVDC components such as capacitors and transformers is their insulating behaviour degrading over time. The dielectric degradation is closely related to the charge transfer process from the metal electrode to the insulation material. Hence, to better understand this issue, a microscopic understanding of the electrical properties of the insulation material and, in particular, charge injection at the interface between the insulation material and the HV electrode should be developed.
The aim of this project is to develop a better understanding of charge injection at the interface between a conductor and a polymer insulator from first‐principles. To begin with, the electronic properties of perfect crystalline metal/polymer systems will be studied based on Density Functional Theory (DFT). Then, structural disorders such as amorphous regions and chemical infections such as O-containing groups and C-halogen bonds which can usually exist in polymers will be considered for realistic interface systems. Interface unit cells containing thousands of atoms will be constructed using Molecular Dynamics method and the electronic properties will then be studied using the state-of-art linear-scaling DFT method. Based on our systematic investigations, our aim is to discover the factors that have the most significant influence on charge injection to help design new insulation materials.