Investigation of optical properties of mixed ligand directed ZnO luminescent nanoparticles for application in light emitting diodes

Developing the heavy metal free QD-LEDs is required to curtail the risks to human beings and environment. Nanoparticles that are ecofriendly, chemically stable, easy to synthesize, nontoxic, biocompatible too are the preferred one. ZnO are biocompatible and low cost semiconductor nanoparticles with tunable band gap and large excitonic binding energy, which make them suitable for LED applications. To achieve the same purpose, this research work is focused on the synthesis of surface modified ZnO nanoparticles for their application in light emitting diodes. The condensation reaction is used to synthesize the ligand and wet chemical precipitation method is used to synthesize surface modified ZnO nanoparticles. The optical properties are evaluated using UV–Vis absorption and fluorescence studies. The optical properties are also investigated in the presence of metal ions and an increased band gap is achieved when Fe³⁺ ion is added to organic receptor coated ZnO nanoparticles. The stability of ZnO coupled receptor is confirmed theoretically using density functional theory.