A novel carbazol derivative as blue emitting material and UV absorber for organic/inorganic hybrid WLED with high Ra and R9 index

Color rendering index (Ra, refers to the average color rendering capacity of 8 colors as defined by Commission Internationale de l'Eclairage) and R9 index (refers to the color rendering capability of red specified by Commission Internationale de l'Eclairage) are important color quality parameters in organic/inorganic hybrid white light emitting diodes (WLEDs). Herein, the novel organic blue emitting material (E)-2-(4-(4-(9H-carbazol-9-yl)styryl)phenyl)-1-phenyl-1H-phenanthro[9,10-d]imidazole (CzSt-PPI) was synthesized. The basic photophysical properties of the CzSt-PPI were studied. An organic/inorganic hybrid WLED using the CzSt-PPI with commercial green and red phosphors was prepared. The Commission Internationale de l'Eclairage chromaticity coordinate of the hybrid WLED is (0.3206, 0.3229) at 34.90 mA. What's more, the Ra and R9 index of the organic/inorganic hybrid WLED reached 90.2 and 87 at 34.90 mA, respectively. It is first time to achieve high Ra and R9 of hybrid WLEDs simultaneously. •A novel blue emitting material CzSt-PPI was synthesized.•The organic/inorganic hybrid WLED MDW-W2 shows Ra of 90.2 and R9 of 87.•This is first report for organic/inorganic hybrid WLED has a high R9 index.