Morphological Evolution of Nickel-Fullerene Thin Film Mixtures

TL;DR

This study explores how external stimuli influence the morphological and electrical evolution of nickel-fullerene thin films, revealing phase separation and structural changes relevant for electronic and energy applications.

Contribution

It provides new insights into the effects of external treatments on hybrid nickel-fullerene thin films, especially regarding phase separation and property modulation.

Findings

Annealing causes strong phase separation in films.

Structural changes lead to increased electrical resistance.

Morphology depends on composition and external stimuli.

Abstract

Hybrid systems consisting of metal-fullerene composites exhibit intriguing properties but often suffer from thermal instability. With proper control, such instability can be harnessed to enable the formation of sophisticated nanostructures with nanometric precision. These self-organization phenomena are not limited to thermal stimulation alone but can also be triggered by other external stimuli. In this work, we investigate the morphological evolution of thin films composed of evaporated C60 and sputtered nickel mixtures, focusing on how external stimuli influence both their structural and electrical properties. Thin films were prepared under controlled deposition conditions, and their surface morphology was analyzed using advanced characterization techniques. Progressive changes in film morphology were observed as a function of composition and external treatment, highlighting the interplay between metallic and molecular components. In particular, it was observed that, due to the annealing treatment, the sample undergoes strong phase separation, with the formation of structures tens of microns in diameter and an increase in electrical resistance, exhibiting insulating behavior. These findings provide insights into the mechanisms governing hybrid thin film formation and suggest potential applications in electronic, optoelectronic, and energy-related devices.