Carbon Quantum Dots and their Possible Application in Perovskites Passivation

High-quality perovskite films are the key factor in manufacturing high performance devices along with outstanding optoelectronic properties. However, methylammonium Lead Iodide (MAPbI3) perovskites are prone to defect formation during the iodide and methylamine ion defect migration. To achieve stable passivation in the perovskite film, additive engineering with nanoparticles can be used as an effective method to passivate the crystal defects. The carboxylic, hydroxyl and amino groups of Carbon Quantum Dots (CQDs) can bond the uncoordinated Pb atoms of the perovskite film creating strong and stable interactions inducing a low trap-state density improving the optoelectronic properties of the perovskite film. Therefore, we study the different functional groups in CQDs by Raman, FTIR, absorbance and photoluminice spectra and propose the addition of CQDs in the perovskite film to reduce the crystal defects and passivate the grain boundaries.