Synthesis and investigation of photonic properties of surface modified ZnO nanoparticles with imine linked receptor as coupling agent- for application in LEDs

Abstract

Wet chemical precipitation route is developed for the synthesis of ZnO nanoparticles using a dipodal receptor as capping agent to control the size and shape of ZnO nanoparticles and also to passivate the surface defects. The capping of ZnO nanoparticles with dipodal receptor is characterized with NMR and IR spectroscopy. EDX analyses also confirmed the presence of organic receptors together with ZnO nanoparticles. The morphology and size of surface modified ZnO nanoparticles is checked by SEM, TEM and DLS spectroscopic techniques. The surface decorated ZnO nanoparticles demonstrate emission peak at 333 nm. The emission peak at 333 nm in case of surface capped ZnO demonstrate fewer surface defects present in comparison to their bulk counterpart, where blue, red, green, yellowish green emission peaks are present. The photophysical studies of ZnO nanoparticles are further carried in presence of metal ions where it is observed that the binding with Mn(II) result in increase in fluorescence intensity. The three fold increase in fluorescence intensity of ZnO nanoparticles in presence of Mn(II) can be utilized in case of lighting devices, where high quantum yield is desirable. To the best of our knowledge, this manuscript represents the first surface decorated ZnO nanoparticles for their application in lighting devices.