Oxidative molecular layer deposition of redox-active thin-film polymers
Abstract
Thin film materials research for a more sustainable future is growing rapidly and new techniques for depositing these films are beginning to surface. One such technique is highlight in this body of work using gaseous precursors to grow bottom-up molecularly controlled polymers, Oxidative molecular layer deposition (oMLD). oMLD promises to enable molecular-level control of polymer structure through monomer-by-monomer growth via sequential, self-limiting, gas-phase surface reactions of monomer(s) and oxidant(s). However, only a few oMLD growth chemistry's have been demonstrated to date and limited mechanistic understanding is impairing progress in this field. Here, we establish key insights into the surface reaction mechanisms underlying oMLD growth. We identify the importance of a two-electron chemical oxidant with sufficient oxidation strength to oxidize both a surface and a gas-phase monomer to enable oMLD growth. The mechanistic insights we report will support rational molecular assembly of co-polymer structures to starkly improve the electrochemical capacity. This work is foundational to unlock molecular-level control of redox-active polymer structure and will enable the study of previously intractable questions regarding the molecular origins of polymer properties, allowing us to control and optimize polymer properties for energy storage, water desalination, and sensors.
Degree
Ph. D.