Communication: Band bending at the interface in polyethylene-MgO nanocomposite dielectric.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Electrical Engineering

Background:

• Polymer nanocomposite dielectrics are crucial for high voltage electrical insulation.
• The underlying physics governing their performance requires further elucidation.
• Understanding interfacial electronic properties is key to optimizing these materials.

Purpose of the Study:

• To investigate the electronic properties at the interface of magnesium oxide-polyethylene nanocomposites.
• To explore the influence of surface treatments on magnesium oxide.
• To develop an improved model for charge trapping mechanisms.

Main Methods:

• Utilizing density functional theory (DFT) simulations.
• Analyzing the electronic band structure at the MgO-polyethylene interface.
• Assessing the impact of silicon surface treatment on MgO.

Main Results:

• Demonstrated matching of polyethylene and magnesium oxide conduction bands.
• Observed significant band bending, creating deep potential wells (up to 2.6 eV).
• Reported a reduction in surface-induced states upon silicon treatment of MgO.

Conclusions:

• The electronic structure at the interface significantly influences dielectric performance.
• Silicon treatment modifies surface properties, potentially enhancing dielectric behavior.
• A new model for charge trapping in nanocomposite dielectrics is proposed based on simulation insights.