Metal filament growth in electrically conductive polymers for nonvolatile memory application

Area of Science:

• Materials Science
• Electrical Engineering
• Polymer Chemistry

Background:

• Nonvolatile memory applications require reliable metal filament formation.
• Previous research predominantly used vacuum deposition methods.
• Understanding the materials science behind reproducible filament formation is limited.

Purpose of the Study:

• Investigate solution-processable polymers for metal filament formation in nonvolatile memory.
• Identify key polymer properties essential for reproducible filament behavior.
• Evaluate polymer performance in terms of device switching endurance.

Main Methods:

• Screened various polymers for their ability to form metal filaments under electrical stimulus.
• Analyzed polymer structures for specific functional groups (heteroatoms like S or N) and electrical conductivity.
• Fabricated and tested memory devices using promising polymer candidates.

Main Results:

• Identified that polymers with strongly coordinating heteroatoms (sulfur or nitrogen) and electrical conductivity enable reproducible filament formation.
• Regiorandom poly(3-hexylthiophene) exhibited superior performance among screened polymers.
• Demonstrated over 30,000 write-read-erase-read cycles with no switching failures for poly(3-hexylthiophene).

Conclusions:

• Solution-processable polymers with specific functionalities are viable for nonvolatile memory fabrication.
• Regiorandom poly(3-hexylthiophene) is a highly promising material for robust resistive switching memory.
• This work advances the understanding of materials for solution-processed electronic devices.