Preparation and Optical Properties Research on Graphene Quantum Dots

摘要

In this work, graphene quantum dots were simply and rapidly prepared by thermal decomposition of citric acid. The resulting graphene quantum dots shows good dispersion and high crystallinity, the sizes can be effectively adjusted by controlling the temperature of decomposition, The results indicate that with the increase of temperature, the size of GQDs increased from 2 nm to 12 nm. The effect of the size of graphene quantum dots on the optical properties were carefully studied. Based on the optical properties and electrochemical results, the HOMO and LUMO value of GQDs with different sizes were obtained and the band gap becomes smaller from 3.36 eV to 2.87 eV with the increase of size of GQDs, which provides a potential application in the field of optoelectronic devices.