title: Origin of Excitation Dependent Fluorescence in Carbon Nanodots.
abstract: The fascinating aspect of excitation dependent fluorescence in carbon nanodots has led to several hypotheses, starting from particle size distribution to the presence of different emissive states and even to sluggish solvent relaxation around nanodot. In this contribution we provide definitive evidence for the involvement of discrete multiple electronic states for the excitation dependent emission in carbon nanodots. The presence of different types of aggregates even at very dilute solutions used in ensemble fluorescence spectroscopy, where fluorescence intensity shows linear dependence with absorbance, is the origin of these multiple electronic states. Inhomogeneous broadening due to slow solvent relaxation leading to excitation dependent spectral shift has negligible influence in conventional solvents.
authors: Radiation & Photochemistry Division, ‡Bio-organic Division, and §Molecular Biology Division, Bhabha Atomic Research Center , Mumbai 400085, India.
authors: Arjun
authors: A
authors: Sharma
authors: Radiation & Photochemistry Division, ‡Bio-organic Division, and §Molecular Biology Division, Bhabha Atomic Research Center , Mumbai 400085, India.
authors: Trilochan
authors: T
authors: Gadly
authors: Radiation & Photochemistry Division, ‡Bio-organic Division, and §Molecular Biology Division, Bhabha Atomic Research Center , Mumbai 400085, India.
authors: Alka
authors: A
authors: Gupta
authors: Radiation & Photochemistry Division, ‡Bio-organic Division, and §Molecular Biology Division, Bhabha Atomic Research Center , Mumbai 400085, India.
authors: Anand
authors: A
authors: Ballal
authors: Radiation & Photochemistry Division, ‡Bio-organic Division, and §Molecular Biology Division, Bhabha Atomic Research Center , Mumbai 400085, India.
authors: Sunil Kumar
authors: SK
authors: Ghosh
authors: Radiation & Photochemistry Division, ‡Bio-organic Division, and §Molecular Biology Division, Bhabha Atomic Research Center , Mumbai 400085, India.
authors: Manoj
authors: M
authors: Kumbhakar