Given the high-energy emission, the choice of host matrix with suitable high triplet energies is very limited. From the photophysical study TSPO1 was identified as the most suitable host matrix to be used in the OLED. The optimized device structure used was: ITO/ HAT-CN (5 nm)/ NPB (40 nm)/ TCTA (10 nm)/ CzSi (10 nm)/ NOBNacene (1.5-6.0 wt%) : TSPO1 (20 nm)/TSPO1 (10 nm)/ TmPyPB (20 nm)/LiF (0.8 nm)/Al (100 nm), where HAT-CH, NPB, TCTA, CzSi, TSPO1, TmPyPB, LiF are the hole injection, hole transporting, electron blocking, exciton blocking, hole blocking, electron transporting, and electron injection layers, respectively. The device structure and energy levels of each layer are illustrated in Figure . OLED devices were fabricated using cD of 1.5 wt%, 3.0 wt%, and 6.0 wt% to understand its effects on both carrier transport and color purity. and compared with literature devices.