Executive Summary : | As about one-fourth of world electricity consumption is used for display and lighting purposes. The highly energy-efficient Organic Light-Emitting Diodes (OLED) displays/lights contribute to saving the Earth’s resources up to 40% compared to the existing technology. Nevertheless, the OLED technology is confined to limited colors or poor brightness. The combination of different colors emitters is used to generate the required color for the OLEDs. In general green, red, and blue are combined to generate the white light as the direct white light-emitting materials are extremely limited. However, the only fluorescent compounds are employed at present for blue emitters due to a dearth of phosphorescent complexes which can meet the criteria for deep blue emissions. Among the known phosphorescent complexes, Ir(III)-N-heterocyclic carbene complexes have attracted the widest attention in 2017 as emitters in electroluminescent devices due to their high quantum yield, and short phosphorescence lifetimes and facile color tunability due to the choice of ligands around the metal center. However, the isolation of highly efficient pure blue phosphorescent metal complexes remains an ambitious target to achieve. Indeed, the thermally stable, long operational lifetime, high-performance color-tunable (without compromising the quantum yield) materials through the organometallics route can overcome the existing limitations to achieve the current technological requirements. Thus the aim of the proposed work is to: (i) synthesize the suitable NHC (N-heterocyclic carbene’s) or N-heterocyclic carbene analogs of N-heterocyclic thione or N-heterocyclic phosphine (NHE’s), supported metal complexes, (ii) tune the color of NHC/NHE-M complexes through aggregation-induced emission, (iii) improve the quantum efficiency and lifetime of molecules, (iv) target the high-performance emitters, (v) understand the photophysical properties through theoretical calculations. |