Novel Fused Core Chromophore Incorporating Spirofluorene and Anthracene Groups for Sky-Blue Emission and Solution-Processed White Devices

Abstract

New blue-light-emitting materials, 2,7-Bis-[1,1′;3′,1″]terphenyl-spiro-fluorene[3,4]naphthalene (TP-AFF-TP) and spiro-fluorene[3,4]-5-terphenylnaphthalene (TP-ASF) were synthesized based on a fused core with anthracene and spirofluorene. The photoluminescence (PL) maximum values of TP-AFF-TP and TP-ASF in film states exhibited 477 nm and 467 nm within the blue region, respectively. Degradation temperature (Td) values for TP-AFF-TP and TP-ASF were very high at 481 °C and 407 °C, respectively. TP-AFF-TP and TP-ASF exhibited power efficiencies (PE) of 1.03 lm/W and 2.39 lm/W, respectively, along with luminance efficiencies (LE) of 2.55 cd/A and 5.17 cd/A, respectively, in nondoped organic light-emitting diode (OLED) devices in which the newly synthesized compounds were employed as emissive layers. The achieved CIE values were (0.25, 0.45) for TP-AFF-TP and (0.17, 0.31) for TP-ASF. Furthermore, when TP-ASF was utilized as one of the emissive materials in solution-processed white OLED devices, the resultant device showcased a notably high LE of 3.13 cd/A, a PE of 2.69 lm/W, and a white CIE value of (0.30, 0.34).

Keywords

• blue-light-emitting materials
• fused core moiety
• anthracene
• spirofluorene groups