Rational design of phenanthroimidazole derivatives with hybridized local and charge-transfer characteristics to achieve efficient blue emission in non-doped OLEDs

Abstract

In this work, two new blue D‒π‒A emitters 4-(2-(3,5-di(9H-carbazol-9-yl) phenyl)-1H-phenanthro[9,10-d] imidazol-1-yl) benzonitrile (DCCPPI) and 4-(2-(3',5'-di(9H-carbazol-9-yl)-[1,1'-biphenyl]-4-yl)-1H-phenanthro[9,10-d] imidazol-1-yl) benzonitrile (DCBCPPI) were designed and synthesized by regulating the distance between phenanthroimidazole and 1,3-di(9H-carbazol-9-yl)benzene....

Oxygen heterocyclic coumarin-based hybridized local and charge-transfer deep-blue emitters for solution-processed organic light-emitting diodes

“…The LE state dominates in the low-polarity solvents ( f < 0.20), while the CT state dominates in the high-polarity solvents ( f > 0.20). 29,57 The μ e values for BCz-6P , p Ph-6P , and o Ph-6P in solvents of low polarity are determined as 13.12, 10.37, and 13.81 Debye, respectively, showing a minimal influence of solvent polarity on the Stokes shift. Conversely, in solvents of high polarity, the μ e values are found to be 25.37, 21.62, and 22.45 Debye, respectively, highlighting a significant effect of solvent polarity on the excited state.…”

“…11,[17][18][19][20][21][22] However, most of them are developed from nitrogen heterocyclic acceptors, particularly imidazoles, such as benzoimidazole, naphthimidazole, and phenanthro [9,10d]imidazole. [23][24][25][26][27][28][29][30] Consequently, developing additional superior acceptors is crucial for broadening HLCT material systems and achieving high-efficiency OLEDs.…”

Efficiency boost in non-doped blue organic light-emitting diodes: Harnessing aggregation-induced emission – a comprehensive review

“…The efficient combination of LE and CT state components in HLCT molecules can not only address the issue of low luminescence quickly caused by the separation of hole and electron wave functions in the CT state, but also inhibit the phenomenon of spectral red-shift and widening, making it suitable for producing high-efficiency blue-light emitters that follow the CIE coordinates (0.15, 0.06). 96,97 The moderate electron-donating and accepting capacities of the PI unit enable the synthesis of efficient HLCT molecules. Meanwhile, the addition of suitable substituents to C2 and N1 of the imidazole skeleton significantly affects the characteristics of materials.…”

Rational design of hybridized local and charge transfer emitters towards deep blue emission by incorporating extra cyano-based acceptor moieties

“…These results favor the development of blue light systems and address current limitations in blue emitters. [20][21][22][23] In this study, leveraging the traditional host material CzTP, 24 we synthesized molecules by selectively eliminating fragments and modulated the excited state by introducing electron-withdrawing cyano groups. Consequently, we designed and synthesized two molecules, 3phCN-phCz and 2(3phCN)-phCz, characterized by HLCT properties.…”

“…These results favor the development of blue light systems and address current limitations in blue emitters. 20–23…”