edgepassivation

Edge passivation is the process of stabilizing or neutralizing reactive edge sites in a material by attaching or forming a protective layer at its boundaries. The goal is to reduce electronic defect states and dangling bonds at edges that can trap charge carriers, catalyze degradation, or cause leakage currents, thereby improving stability, optical performance, and device efficiency.

Common approaches include chemical termination with hydrogen, sulfur, oxygen, or other groups; formation of thin insulating or passivating layers such as oxides, nitrides, or organic-functionalized coatings; deposition of self-assembled monolayers or organic ligands; and precise control of edge termination during synthesis to favor specific edge configurations. Techniques such as selective chemical treatments, plasma processing, and atomic layer deposition are often employed to achieve conformal edge coverage.

Edge passivation is particularly important in nanoscale and two-dimensional materials, where a large fraction of atoms reside at or near edges. In 2D materials like graphene, MoS2, and phosphorene, edge states can strongly influence electronic, optical, and catalytic properties. Proper passivation can reduce nonradiative recombination, stabilize edge chemistry against oxidation, and tailor catalytic activity or charge transport along the edges.

Applications span semiconductor devices, solar cells, nanoribbons, and sensors, where improved edge stability translates to higher performance and longer device lifetimes. Challenges include achieving selective, durable passivation without compromising edge functionality, as well as scalability and compatibility with device fabrication processes.