Tejerina Lara, Rapidis Alexandros G, Rickhaus Michel, Murto Petri, Genene Zewdneh, Wang Ergang, Minotto Alessandro, Anderson Harry L, Cacialli Franco
Chemistry Research Laboratory, Department of Chemistry, University of Oxford Oxford OX1 3TA UK
Department Physics and Astronomy and London Centre for Nanotechnology, University College London London WC1E 6BT UK
J Mater Chem C Mater. 2022 Mar 14;10(15):5929-5933. doi: 10.1039/d1tc05951c. eCollection 2022 Apr 14.
The luminescence and electroluminescence of an ethyne-linked zinc(ii) porphyrin pentamer have been investigated, by testing blends in two different conjugated polymer matrices, at a range of concentrations. The best results were obtained for blends with the conjugated polymer PIDT-2TPD, at a porphyrin loading of 1 wt%. This host matrix was selected because the excellent overlap between its emission spectrum and the low-energy region of the absorption spectrum of the porphyrin oligomer leads to efficient energy transfer. Thin films of this blend exhibit intense fluorescence in the near-infrared (NIR), with a peak emission wavelength of 886 nm and a photoluminescent quantum yield (PLQY) of 27% in the solid state. Light-emitting diodes (LEDs) fabricated with this blend as the emissive layer achieve average external quantum efficiencies (EQE) of 2.0% with peak emission at 830 nm and a turn-on voltage of 1.6 V. This performance is remarkable for a singlet NIR-emitter; 93% of the photons are emitted in the NIR ( > 700 nm), indicating that conjugated porphyrin oligomers are promising emitters for non-toxic NIR OLEDs.
通过在两种不同的共轭聚合物基质中测试一系列浓度的混合物，对乙炔连接的锌（II）卟啉五聚体的发光和电致发光进行了研究。对于卟啉负载量为1 wt%的与共轭聚合物PIDT-2TPD的混合物，获得了最佳结果。选择这种主体基质是因为其发射光谱与卟啉低聚物吸收光谱的低能量区域之间有出色的重叠，从而导致有效的能量转移。这种混合物的薄膜在近红外（NIR）区域表现出强烈的荧光，固态下的峰值发射波长为886 nm，光致发光量子产率（PLQY）为27%。以这种混合物作为发光层制造的发光二极管（LED），平均外部量子效率（EQE）为2.0%，峰值发射波长为830 nm，开启电压为1.6 V。对于单重态近红外发射体来说，这种性能非常出色；93%的光子在近红外区域（>700 nm）发射，这表明共轭卟啉低聚物是无毒近红外有机发光二极管有前景的发射体。
