Emission characteristics of carbon films in comparison with solvatochromic effects of carbon nanoparticles.

Carbon nanoparticles (CNPs) are getting wide attention due to their fluorescence and low level of toxicity compared to other semiconducting photoluminescent materials. CNPs show strong 'solvatochromism', and the emission mechanism is still under discussion. Florescent carbon in the form of films would tremendously increase its potential for applications. In this work, we report for the first time the fluorescent emission characteristics of carbon films formed by aggregation of CNPs. Films of carbon were grown on glass substrates by using a novelCold Vapour Deposition System. We have performed a detailed comparative study of the emission spectra of film and CNPs (prepared using the microwave synthesis method) in various solvents. A qualitative model based on solvatochromism of CNPs is used to understand the emission pathways in the film.