A novel white natural sources light-emitting diode (WOLED) was invented by incorporating a new blue through heat triggered delayed fluorescent substance, 4,6-di(9H-carbazol-9-yl)- isophthalonitrile (DCzIPN), as a dual blue emitter and a host for a yellow phosphorescent the point of emission. This hybrid WOLED achieved an impressive exterior quantum efficacy exceeding 20%. DCzIPN exhibited a significant quantum effectiveness of 16.4% as a blue emitter and 24.9% as a host for a yellow phosphorescent emitter. The WOLEDs, which combine DCzIPN host and the source layers, demonstrated a remarkable external quantum efficiency of 22.9%. These devices achieved a warm white colour coordinate of (0.39, 0.43) and a quantum effectiveness of 21.0% for cool white colour coordinates (0.31, 0.33). These impressive results were achieved by carefully controlling the thickness of the yellow emitting layers