Energy transfer studies between organic fluorophores are often manipulated by regulating the binding affinity between acceptor and donor moieties. However, understanding of energy transfer process involving nanocrystal and organic molecules is at a very early stage. Recently, it has been suggested that pendant groups of acceptor molecules can also regulate their binding affinity toward perovskite nanocrystals. An obvious question thus arises-how does electronegative atom (e.g. iodine, chlorine) of acceptor molecule influence its binding affinity to perovskite nanocrystal? The role of crystal facets in doped-PNCs cannot be ignored as it has also been shown that facet {100} FAPbI3 strongly interacts with highly polar water molecules. 9