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Abstract: For highly luminescent solid-state applications, the twisted or spiro-configured conjugated molecules are mostly considered as the proper choices because the coplanar ones usually have intensively intermolecular π–π interactions, which lead to fluorescence quenching and red-shift. In this study, the two prepared parallel H-shaped phenylenevinylenes with coplanar configuration show the special case. Due to their characteristics of multi-branches, these coplanar multi-branched molecules prefer to form stable amorphous morphology in thin films were verified by the XRDs and AFM. The amorphous thin films show very weak intermolecular actions, with intrinsic differences on both steady and transient optical properties from the crystalline states. The non-doped electroluminescent devices based on them show highly luminescent blue emissions. Both their luminance (20490cdm−2) and efficiency (2.8cdA−1/2.6lmW−1) are comparable with the performances of the cross dimeric OPVs which have similar constructing blocks to the H-shaped molecules and with the same EL device configurations. [Copyright &y& Elsevier]

Abstract: We reported an asymmetric phenylenevinylene with a cis double bond 2-(4-(p-tolyl)styryl)-1,4-dip-tolylbenzene (cis-TSDTB) and its use as efficient deep-blue emitter for organic light-emitting diodes (OLEDs) applications. The crystal structure of cis-TSDTB showed torsion configuration and asymmetric geometry, which make it packing in a reduced intermolecular interaction arrangement. And its single crystals showed excellent fluorescence owing to this unique molecular configuration. Typical OLEDs using cis-TSDTB as non-doped emitters exhibited saturated blue light with the CIE 1931 coordinates of (0.15,0.10), which is quite close to the National Television Standards Committee (NTSC) blue standard. High luminescence efficiency (3.4cdA−1) and high brightness (9855cdm−2) have been realized in the device. All of these outstanding results indicated that cis-phenylenevinylene will be a promising candidate as blue light-emitting materials. [Copyright &y& Elsevier]