Organic electronics, mainly due to advancements in OLED (Organic Light Emitting Diode) technology, is a fast developing research area having already revolutionised the displays market. This project will demonstrate the use of thermally activated delayed fluorescence (TADF) and Room Temperature Phosphorescence (RTP) emitters in high-efficiency OLEDs, that are stable and do not use scarce and expensive materials such as iridium. The proposed project deals with the comprehensive task of synthesis and analysis of novel ambipolar compounds containing carbazole, phenothiazine, phenoxazine, acridine etc. with different acceptor units based on phenazine, arylene bisimide, Diphenylphosphine and dibenzoselenophene Se, Se-dioxides groups, characterisation of these compounds and the construction and testing of warm white OLED devices.