Highly efficient air-stable colloidal quantum dot solar cells by improved surface trap passivation

Highly passivated PbS CQDs were developed using a novel iodide based ligand, 1-propyl-2,3-dimethylimidazolium iodide (PDMII). The effects of PDMII on the surface quality of PbS-CQDs were investigated. By using PDMII, improved surface passivation with reduced sub-bandgap trap-states was achieved. Solar cell devices using our PDMII based CQDs displayed state-of-the-art PCE (10.99%) and air stability with low energy loss (0.447 eV).202