Cesium Lead Halide perovskite nanocrystals (NCs) CsPbX3 (X=Cl, Br, I) have been prominent materials for the last few years due to their high photoluminescence quantum yield (PLQY) owing to light-emitting diodes (LEDs) and other significant applications in photovoltaics and optoelectronics. Meanwhile, there is still a challenge of maintaining its photo-stability and PLQY, which degrades because of ligand loss via proton transfer between oleic acid and oleylamine (commonly used surface capping ligands). In this presentation, I will discuss a facile and efficient completely amine-free synthesis of cesium lead bromide perovskite nanocrystals using a novel bromide source and n-trioctylphosphine (TOP) as a ligand in open atmospheric conditions. These completely amine-free CsPbBr3 perovskite NCs synthesized using bromine-rich conditions exhibit good stability and durability for more than three months in the form of colloidal solutions and films, respectively. These amine-free CsPbBr3 NCs films exhibiting high photoluminescence (PL) at open atmospheric conditions, which can be further used for optoelectronic device applications. Furthermore, surface passivation is an efficient way to enhance the optoelectronic properties and colloidal stability of perovskite materials. So far, oleic acid and oleylamine binary ligands have been used to prepare CsPbX3 NCs. I will share the results of the photostability of these nanocrystals with respect to various capping ligands for surface passivation to obtain high photostability and good in NCs dispersions. At the end of this presentation, I will discuss the impact of CsPbBr3 nanocrystal surface modification on the excited state interactions with the electron/hole acceptor molecules for efficient photocatalytic application.