Directed Self-Assembly of Block Copolymers for High Breakdown Strength Polymer Film Capacitors

Area of Science:

• Materials Science
• Polymer Science
• Nanotechnology
• Electrical Engineering

Background:

• High-power, lightweight, and flexible electronics demand solid-state capacitors with high energy densities and fast charge/discharge rates.
• Current polymer film capacitors have energy densities insufficient for emerging electronic applications.
• Enhancing breakdown strength (EBD) and dielectric permittivity (εr) are key to improving capacitor performance.

Purpose of the Study:

• To develop novel multilayer, multicomponent block copolymer dielectric films (BCDF) for high energy density capacitors.
• To investigate the effect of self-assembly and nanostructure on the dielectric properties of block copolymers.
• To explore a new nanomaterial paradigm for designing advanced dielectric materials.

Main Methods:

• Fabrication of multilayer, multicomponent block copolymer dielectric films (BCDF) using directed self-assembly.
• Utilized soft-shear driven highly oriented self-assembled lamellar diblock copolymers (BCP).
• Characterized the breakdown strength (EBD) of self-assembled films compared to unordered films.

Main Results:

• Achieved approximately 50% enhancement in breakdown strength (EBD) for self-assembled multilayer lamellar BCP films compared to as-cast films.
• Demonstrated that dielectric breakdown is highly sensitive to the nanostructure of the block copolymer.
• Attributed EBD enhancement to the 'barrier effect' of multiple lamellar interfaces, leading to more than double the energy storage capacity.

Conclusions:

• Directed self-assembly of block copolymers is a viable strategy for creating high energy density dielectric materials.
• The developed BCDF exhibit superior dielectric breakdown strength, crucial for advanced capacitor applications.
• This approach offers a new pathway for designing next-generation dielectric materials for flexible and high-power electronics.