Microwave assisted synthesis of CuInGaSe2 quantum dots and spray deposition of their composites with graphene oxide derivatives

In this contribution, we explore a spray deposition technique to prepare thin films based on nanocomposites of graphene oxide (GO) or reduced graphene oxide (rGO) with CuInGaSe2 quantum dots (QD) synthesized by a microwave-assisted method. Small nanocrystals in the tetragonal phase and emitting light at 650 nm were obtained. Water-based solutions of the nanocomposites were sprayed onto transparent conductive glass substrates using an automated ultrasonic spray system and the resulting thin films were evaluated with respect to their morphological and electrochemical properties. The distribution and organization of the graphene sheets in the composites were affected by the interaction between the nanocrystals and GO or rGO, which also interfered on the electronic properties. In addition, we demonstrated a possible application of the thin film based on the rGO-QD composite as a counter electrode in dye-sensitized solar cells.