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Boron subphthalocyanine (SubPc) is a small molecule active material that absorbs visible light efficiently at wavelengths ranging from 500 to 600 nm. Recent studies have demonstrated that blending SubPc and C60 (fullerene) as the active layer in organic photodetectors (OPDs) results in a high dark current and decreases detectivity. Moreover, N,N′-bis(naphthalen-1-yl)-N,N′-bis(phenyl)benzidine (NPB) can be employed as a blocking layer and as a donor on the active layer. In this study, the performance of OPDs is investigated using non-fullerene (NPB : SubPc) and fullerene (SubPc : C60) active layers. The OPD utilizing a non-fullerene-based device (NPB : SubPc) with a ratio of 1 : 3 exhibits high performance across various parameters. It demonstrated a low dark current density of 1.32 × 10−9 A cm−2, an external quantum efficiency (EQE) of 51.85%, a responsivity of 0.22 A W−1, and a high detectivity of 1.07 × 1013 Jones at a wavelength of 530 nm. Moreover, the device showed a linear dynamic range (LDR) of 109.29 dB, a frequency cut-off of 263.04 kHz, and a transient photovoltage in formed rise and fall times of 2.74 μs and 1.51 μs, respectively. These findings suggest that the developed device could be suitable for future fingerprint recognition, owing to its ability to detect visible green light. [ABSTRACT FROM AUTHOR]

The luminescent characteristics of liquid crystalline molecules based on 4-alkyl-4′-cyanobiphenyl, such as 4′-pentyl-4-cyanobiphenyl (5CB), have been less explored due to the fluorescence quenching arising from intermolecular dipole–dipole interactions and free intramolecular motion. Herein, we reported three 4-alkyl-4′-cyanobiphenyl-based molecules, i.e., 2CB-NC2O, 2CB-NC3O and 2CB-NC4O, with aggregation-induced emission (AIE) properties. Notably, 2CB-NC2O and 2CB-NC3O demonstrate a liquid crystalline smectic A phase at room temperature in addition to their AIE properties. The AIE properties of these molecules are caused by the intermolecular hydrogen bonding between –OH and –NH groups on the alkyl chain, which restricted the intermolecular motion to facilitate the radiative decay in their state of aggregation. Furthermore, in contrast to 5CB which exhibits an anti-parallel alignment, the 4-alkyl-4′-cyanobiphenyl-based molecules exhibited a parallel alignment induced by intermolecular hydrogen bonding, resulting in the inhibition of dipole–dipole quenching of their fluorescence. This study not only introduces a novel design concept for luminescent LCs, but also offers a strategic approach to enhance the fluorescence of dipolar molecules through intermolecular hydrogen bonding. [ABSTRACT FROM AUTHOR]

This study utilized a two-dimensional numerical viscous wave tank to simulate the run-up and run-down processes of non-breaking solitary waves on a steep seawall. The research aimed to investigate the transformation between wave potential energy and kinetic energy, the evolution mechanisms of the wave and flow fields, and the correlation between the dynamic pressure gradient and the reverse flow near the sloping bed. The numerical model results were consistent with laboratory measurements of free surface elevations and flow velocity profiles, demonstrating the accuracy of the numerical model. This study focused on a solitary wave with a wave-height-to-water-depth ratio of 0.15, propagating on a representative seawall with a steep slope of 1:3 along the western coast of Taiwan. The simulation results indicate that the maximum run-up height occurs when the potential energy is at its highest. Undertow is caused by the adverse pressure gradient within the flow field, and the dynamic pressure on the sloping bed is directly proportional to the free surface elevation. Therefore, by observing the spatial changes in the free surface elevation, we can indirectly determine the occurrence time of undertow. [ABSTRACT FROM AUTHOR]

Phycotoxins or marine toxins cause massive harm to humans, livestock, and pets. Current strategies based on ordinary methods are long time-wise and require expert operators, and are not reliable for on-site and real-time use. Therefore, it is urgent to exploit new detection methods for marine toxins with high sensitivity and specificity, low detection limits, convenience, and high efficiency. Conversely, biosensors can distinguish poisons with less response time and higher selectivity than the common strategies. Aptamer-based biosensors (aptasensors) are potent for environmental monitoring, especially for on-site and real-time determination of marine toxins and freshwater microorganisms, and with a degree of superiority over other biosensors, making them worth considering. This article reviews the designed aptasensors based on the different strategies for detecting the various phycotoxins. [ABSTRACT FROM AUTHOR]