56990-02-4Relevant articles and documents
Alkyl-thiophene Functionalized D-π-A Porphyrins for Mesoscopic Solar Cells
Lu, Jianfeng,Liu, Shuangshuang,Shen, Yan,Xu, Jie,Cheng, Yibing,Wang, Mingkui
, p. 187 - 196 (2015)
An alkyl-thiophene functionalized D-π-A porphyrin (LW16) is designed and synthesized for dye-sensitized solar cells (DSSCs). Two hexyl-thiophene groups are attached to the meta-position of each meso-phenyl with a motivation to increase the light-harvesting ability as well as retarding the aggregation of porphyrins dyes. For comparison, none-alkyl substituted (LW14) and octyloxy substituted (LW15) porphyrin dyes are also synthesized to fully investigate the influence of porphyrin chromophore modification. These porphyrins present similar spectrum while the oxidation potentials vary as the functionalized group changes from the meta-position to ortho-position. The DSSCs based on the alkyl-thiophene functionalized (LW16), none-alkyl substituted (LW14), and octyloxy substituted (LW15) porphyrins can be achieved a power conversion efficiency of 8.5%, 6.9%, and 8.2% using I-/I3-redox electrolyte under full sunlight irradiation (AM 1.5 G, 100 mW cm-2), respectively. It is found that by tailoring the porphyrin chromophore with hexyl-thiophenes, the photocurrent of the corresponding devices could be increased without sacrifice the photovoltage. Detailed investigation, including spectroscopy, electrochemical and transient photovoltage decay measurement, provides general influence of π-conjugation extension at the meso-position onto the optoelectronic features of porphyrins dyes.
Meso-substituted boron-dipyrromethene compounds: synthesis, tunable solid-state emission, and application in blue-driven LEDs
Liu, Hao,Su, Huan,Chen, Zhiyuan,Zhu, Senqiang,Liu, Rui,Zhu, Hongjun
, p. 1697 - 1705 (2021/07/10)
In this work, we depict the synthesis and characterization of a series of meso-substituted boron-dipyrromethene (BODIPY) compounds. Their optical and electrochemical properties were investigated systematically. All these compounds exhibited intense absorption bands in the ultraviolet (UV) and visible regions, which arise from the π–π* transitions based on their BODIPY core segments. By comparing electron-withdrawing substituents and electron-donating substituents, we found that these compounds exhibited some similar photophysical properties but exhibited different fluorescence in the solid state. All compounds were highly emissive in dichloromethane at room temperature (λem = 512–523 nm, ΦPL > 0.9). When these compounds were applied in blue-driven light-emitting diodes (LEDs) as light-emitting materials, the devices showed luminescence efficiency ranging from 1.09 to 34.13 lm/W. Their luminescence and electrochemical properties could be used for understanding the structure–property relationship of BODIPY compounds and developing functional fluorescent materials.
Stable and efficient phosphorescent organic light-emitting device utilizing a δ-carboline-containing host displaying thermally activated delayed fluorescence
Liu, Shihao,Wang, Hui,Xie, Wenfa,Zang, Chunxiu,Zhang, Letian,Zhao, Hongyu
, p. 3800 - 3806 (2020/03/31)
Materials displaying thermally activated delayed fluorescence (TADF) can when used as hosts alleviate the serious efficiency roll-off of phosphorescent organic light-emitting devices (PHOLEDs). However, the stability of the device remains challenging due to the unstable moiety in the TADF molecule. Here, a stable and efficient yellow PHOLED based on a δ-carboline-containing TADF host and bis(4-phenyl-thieno[3,2-c]pyridinato-C2′) (acetylacetonato) iridium(iii) (PO-01) guest was demonstrated. Compared to the lifetime of the PHOLED with a 4,4′-bis(N-carbazolyl)-2,2′-biphenyl host, a greater than twenty times enhancement of the lifetime of the PO-01-based device was achieved. The LT50 lifetime (time to 50% of initial luminance of 1000 cd m-2) of an unpackaged DCb-BPP-based PHOLED reached 424 h, and was accompanied by a maximum external quantum efficiency of 21.5% and an impressive low efficiency roll-off of 17.7% at a high luminance of 10 000 cd m-2. These values are among the best of those reported for PO-01-based yellow PHOLEDs.
