Swift Heavy Ion Induced Modification Studies of C60 Thin Films

TL;DR

This study investigates how swift heavy ion irradiation affects C60 thin films, revealing molecular modifications at low fluences and amorphization at high fluences through spectroscopy analyses.

Contribution

It provides detailed insights into the structural and electronic changes in C60 films caused by swift heavy ion irradiation, highlighting the formation of nanocrystalline carbon structures.

Findings

Low fluences induce molecular formations like dimers and polymers.

High fluences cause amorphous carbon and sub-molecular nanocrystalline structures.

Raman and optical data confirm the transition from molecular to amorphous states.

Abstract

Modification induced by 110 MeV Ni ion irradiated thin film samples of C60 on Si and quartz substrates were studied at various fluences. The pristine and irradiated samples were investigated using Raman spectroscopy, electrical conductivity and optical absorption spectroscopy. The Raman data and band gap measurements indicate that swift ions at low fluences result in formations that involve multiple molecular units like dimer or polymer. High fluence irradiation resulted in sub-molecular formations and amorphous semiconducting carbon, indicating overall damage of the fullerene molecules. These sub-molecular units have been identified with nanocrystalline diamond and nanocrystalline graphite like formations.