Investigating the Effect of Substrate on Optical Properties of Undoped and Chlorine Doped Graphene Quantum Dots

The influence of substrate on the graphene is an important subject to study as it may alter the properties of graphene. Herein we report the effect/ involvement of substrate on optical properties of un-doped and doped GQDs. Cl doped GQDs was selected for the study wherein Cl doping was done using hydrochloric acid as Cl source. Furthermore, silicon (Si), SiC (SiC) and graphene/SiC (G/SiC) was selected as three different substrates for the study. The graphene/SiC used was grown via thermal decomposition of SiC (SiC) substrates. With the intention to observe the effect of substrate on the optical properties of GQDs, the undoped and Cl-GQDs was drop casted on each substrate. The surface morphology, thickness, structure and optical properties of GQD have been assessed by atomic force microscopy (AFM), scanning electron microscopy (SEM), photoluminescence (PL) and time resolved PL (TRPL). The photoluminescence (PL) measurements of undoped and Cl-GQDs showed no change in emission peaks which demonstrated that substrate have no effect on luminescence of GQDs. Further on, TRPL measurements of undoped and Cl-GQDs revealed the bi-exponential behavior with no observable effect on the short and long lifetime component on each substrate Received date: 12/09/2017 Accepted date: 27/09/2017 Published date: 03/10/2017