Deep‐blue fluorescent compounds are particularly important in organic light‐emitting devices (OLEDs). A donor–accepotor (DA)‐type blue‐emitting compound, 1‐(10‐(4‐methoxyphenyl)anthracen‐9‐yl)‐4‐(10‐(4‐cyanophenyl)anthracen‐9‐yl)benzene (BD3), is synthesized, and for comparison, a nonDA‐type compound, 1,4‐bis(10‐phenylanthracene‐9‐yl)benzene (BD1) and a weak DA‐type compound, 1‐(10‐phenylanthracen‐9‐yl)‐4‐(10‐(4‐cyanophenyl)anthracen‐9‐yl)‐benzene (BD2), are also synthesized. The twisted conformations of the two anthracene units in the compounds, confirmed by single crystal X‐ray analysis, effectively prevent π‐conjugation, and the compound shows deep‐blue photoluminescence (PL) with a high PL quantum efficiency, almost independent of the solvent polarity, resulting from the absence of an intramolecular charge transfer state. The DA‐type molecule BD3 in a non‐doped device exhibits a maximum external quantum efficiency (EQE) of 4.2% with a slight roll‐off, indicating good charge balance due to the DA‐type molecular design. In the doped device with 4,4′‐bis(N‐carbazolyl)‐1,1′‐biphenyl (CBP) host, the BD3 exhibits higher EQE than 10% with Commission International de L'Eclairge (CIE) coordinates of (0.15, 0.06) and a narrow full‐width at half‐maximum of 45 nm, which is close to the CIE of the high definition television standard blue.

This article is written to provide an up-to-date review of porphyrin-based materials used in organic solar cells (OSCs).

Novel butterfly-shaped, highly fluorescent stable monomers of the type 7-tert-butyl-1,3,5,9-tetrakisarylpyrene were synthesized by the Suzuki-Miyaura coupling reaction of the new bromopyrene derivative 7-tert-butyl-1,3, 5,9-tetrabromopyrene with the corresponding arylboronic acids.

A new series of pyrene-based, pure-blue, fluorescent, stable monomers, namely 2,7-di-tert-butyl-4,5,9,10-tetrakis(p-Rphenylethynyl)pyrenes, have been successfully synthesised by Pd/Cu-catalysed Sonogashira coupling in excellent yield. The cruciform-shaped, π-conjugated structures were fully characterised by 1 H/ 13 C NMR and IR spectroscopy, mass spectrometry and elemental analysis. As revealed from single-crystal X-ray analysis, there is a herringbone pattern be-

A series of pyrene-based Y-shaped blue emitters, namely, 7-tert-butyl-1,3-diarylpyrenes 4 were synthesized by the Suzuki cross-coupling reaction of 7-tert-butyl-1,3-dibromopyrene with a variety of p-substituted phenylboronic acids in good to excellent yields. These compounds were fully characterized by X-ray crystallography, UV/Vis absorption and fluorescence spectroscopy, DFT calculations, thermogravimetric analysis, and differential scanning calorimetry. Single-crystal X-ray analysis revealed that the Y-shaped arylpyrenes exhibited a low degree of π stacking owing to the steric effect of the bulky tert-butyl group in the pyrene ring at the 7-position, and thus, the intermolecular π-π interactions were effectively suppressed in the solid state. Despite the significantly twisted nonplanar structures, these molecules still displayed efficient intramolecular charge-transfer emissions with clear solvatochromic shifts on increasing solvent polarity. An intriguing fact is that all of these molecules show highly blue emissions with excellent quantum yields in the solid state. Additionally, the two compounds containing the strongest electron-accepting groups, CN (4 d) and CHO (4 f), possess high thermal stability, which, together with their excellent solid-state fluorescence efficiency, makes them promising potential blue emitters in organic light-emitting device applications.

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A pyrene-containing single-molecule excimer-emitting compound, 1,8-bis(pyren-2-yl)naphthalene (BPyN), was synthesized. With BPyN as a host emitter, C545T-based green OLEDs were fabricated, exhibiting high efficiencies of 22 lm W(-1), 22 cd A(-1) and 6.2% external quantum efficiency (EQE) at 100 cd m(-2), and 19 lm W(-1), 22 cd A(-1) and 6.2% EQE at 1000 cd m(-2).

light absorption, [3,4] long diffusion length, [5] and low trapping densities. [6] The certified power conversion efficiency of perovskite solar cells has arrived at 22.1%. [7] Meanwhile, the newly developed photodetectors based on large size single-crystals also attained high performances. [8][9][10][11][12][13][14][15][16] So far, large-size singlecrystals have presented much longer charge carrier diffusion lengths and significantly lower trap-state densities, [5] but one of the key benefits of the thin-films is that it combines flexibility with the prospect of further improvements toward continuous, high throughput roll-to-roll (R-2-R) processing.The relative poor photophysical properties of perovskite thin-films are attributed to the inhibition of charge transport by the trap states due to random macroscopic alignment and crystal orientation that are rooted from poor crystal packing. For example, polycrystalline grains, which are always observed in spin-cast films, [17][18][19] exhibit large number of associated grain boundaries in which traps deteriorate quantum efficiency and photocarrier lifetime. [20] To narrow down the gap in photophysical property between the thin-films and single-crystals, it has become imperative to understand and to eventually achieve optimized crystal packing. Unfortunately, obtaining controlled packing through solution coating remains challenging, partly due to fast solvent evaporation, stochastic nucleation, and fluid flow instabilities. [21,22] There have been attempts to address above challenges. For example, 1D nanowires have been developed with fewer grain boundaries, traps, and longer photocarrier lifetime than their nanograin counterparts. [23][24][25] However, fabrication of uniformly coated large-area device appears to be challenging. [26] Bakr and co-workers developed a thermal-gradient-assisted directional crystallization to produce fully covered periodic microarrays with high crystal orientation and anisotropic charge transport properties. [27] However the thermal-gradient-assisted directional crystallization can be readily interrupted by airflow; and the crystal formation often takes hours to complete, making it unfavorable for high-throughput large-scale fabrication. Other approaches such as microgravure printing, slip-coating, and blade-coating were also reported to fabricate macroscopic aligned crystals, [16,26,28] however there were no information Solution coating of organohalide lead perovskites offers great potential for achieving low-cost manufacturing of large-area flexible optoelectronics. However, the rapid coating speed needed for industrial-scale production poses challenges to the control of crystal packing. Herein, this study reports using solution shearing to confine crystal nucleation and growth in large-area printed MAPbI 3 thin films. Near single-crystalline perovskite microarrays are demonstrated with a high degree of controlled macroscopic alignment and crystal orientation, which exhibit significant improvements in optical and optoelectronic propert...