Temperature Dependent Electrical Resistance of Proton Irradiated and Non-irradiated C60 Micro-rods

Self-assembled fullerene C60 micro-rods on borosilicate substrates were synthesized via liquid-liquid interfacial precipitate method (LLIP) and subsequently irradiated with 2 MeV H+ with fluencies ranging from 5.0 × 1013 - 9.0 ×1015 H+cm-2. The resistance measurements were conducted under light illumination of white, red, yellow and blue colors and the results were compared to zero illumination. After H+ irradiation, the fullerene C60 micro-rods became chemically inert due to weakened C–C bonds within C60 molecules that generated polymeric yields that are insoluble in toluene. Alteration in optical band-gap triggering color transformation from black to yellowish was observed, signifying the existence of loosely bound pi-electrons being excited by visible light. Resistivity measurements revealed wavelength and temperature dependent hysteresis with first order transition behavior at 337 K. These behaviors qualify fullerene C60 micro-rods for optoelectronic switches and optical sensors applications.