This shift prevails also in thin films and electroluminescence experiments as well as for other perovskite nanocrystals, such as CsPbBr3 (Fig. ), indicating that it is specific to the presence of DCzGPC and not, for instance, a solvent effect or a change in halide composition. By X-ray photoelectron spectroscopy (XPS), we exclude the presence of a chloride contamination in pure DCzGPC as a potential reason for the hypsochromic shift (Fig. ). We note that a concentrationdependent hypsochromic shift after addition of different bidendate ligands was also observed by other groups. However, in those cases the NC size shrunk during ligand exchange, such that the shift was explained in terms of increased quantum confinement. In the present case, we observe the opposite, i.e., a slight increase in the NC size, which rules out increased quantum confinement as an explanation for the blue shift.