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In this paper, two D–π–A structured self-assembly monolayers (SAMs: FNE29 and DT-1) are self-assembled onto the indium tin oxide (ITO) substrates as hole-transport layers (HTLs) for inverted perovskite solar cells (PSCs). Due to the presence of a terminal –COOH group, the SAMs can be adsorbed onto the surface of the ITO substrate through the covalent self-assembly. The employed FNE29 and DT-1 SAMs differ in the π bridge (linker); the FNE29 SAM has a hexyl-substituent terthiophene while the DT-1 SAM contains dithienopyrrolobenzotriazole as the linkers, respectively. Upon the self-assembly of ITO with the SAMs, the power conversion efficiency (PCE) is enhanced from 9.36% for the control device to 16.75% for the FNE29 modified device and further to 20.65% for the DT-1 modified PSCs. As the D–π–A structured SAMs with a large fused π bridge as a linker is beneficial for hole transfer, the self-assembly of DT-1 achieves a higher PCE with an improved fill factor. Moreover, due to the good hydrophobic characteristics of the SAMs, the inverted PSC devices self-assembled with these two molecules display good stability, maintaining over 80% of the original PCE after storage in air (relative humidity of 20–30%) for ∼1000 h without encapsulation. In addition, the FNE29 and DT-1 based devices also show good photostability after operating for 1000 h. These results indicate that the D–π–A structured SAMs with large conjugated fused π bridges as linkers have obvious advantages as the HTLs for inverted PSCs. [ABSTRACT FROM AUTHOR]

In this paper, the encapsulated insulated molecular wire (EIMW) and 2′,7′-bis(hexyloxy)spiro[cyclopenta[2,1-b:3,4-b′]dithiophene-4,9′-fluorene] (SPDF) were specifically designed as efficient anti-aggregation π-bridges for two novel D–A–π–A metal-free sensitizers (IBT1 and IBT2). Compared with the reference dye IBT3 with 3,3′-dihexyl-2,2′-bithiophene (DHBT) as an anti-aggregation π-bridge, both the dyes IBT1 with EIMW and IBT2 with SPDF as π-bridges can suppress intermolecular aggregation more efficiently. The π-bridge of SPDF shows the strongest anti-aggregation ability due to the rigid 'T' configuration among these dyes. Meanwhile, the π-bridge of EIMW shows better anti-aggregation ability than DHBT because of the larger steric hindrance of the former. Finally, when the dyes IBT1 and IBT2 are co-sensitized with IBT3, respectively, the new devices exhibit high efficiencies of 7.85% and 7.64%, respectively, which are comparable to that of N719 (7.85%). The results demonstrate that the dyes with EIMW and SPDF as anti-aggregation π-bridges are promising candidates for efficient DSSCs and dye aggregation can be effectively inhibited by structural engineering of the π-spacer. [ABSTRACT FROM AUTHOR]

Double branched donor acceptor compounds (D–π–A)2L, whose separate branches are linked by saturated chains or ring systems, are highly promising sensitizers for dye-sensitized solar cells (DSSCs). Their photovoltaic performance η (power conversion efficiency PCE) is higher than the η value of the corresponding single branched sensitizers D–π–A. This advantage can be attributed to the lower aggregation tendency and to the higher loading density of the chromophores on the semi-conductor surface (TiO2). Moreover, the intramolecular transfer of the excitation energy can enhance the contact time of the adsorbed dye molecules in the excited state S1 and thus reduce the unwanted charge recombination (dark current). [ABSTRACT FROM AUTHOR]

As an emerging photovoltaic technology, dye-sensitized solar cells (DSSCs) have attracted a great deal of academic and industrial interest due to their reasonably high power conversion efficiency, low material cost and facile fabrication process. Metal-free organic dyes, as one of the key components of DSSCs, play a pivotal role in light harvesting and electron injection. Among the various species of organic dyes, easily tunable 10H-phenothiazine-based dyes hold a large proportion. The electron-rich nitrogen and sulfur atoms render 10H-phenothiazine a stronger donor character than other amines, even better than triphenylamine, tetrahydroquinoline, carbazole and iminodibenzyl. On the other hand, the unique non-planar butterfly conformation of the 10H-phenothiazine ring can sufficiently suppress molecular aggregation and the formation of excimers. The positions N-10, C-3 and C-7 of the 10H-phenothiazine ring system can easily be furnished with electron-donating or electron-withdrawing groups. Thus, the structural features of 10H-phenothiazine-based dyes guarantee the fabrication of efficient DSSCs. Some 10H-phenothiazine-based dyes show high photovoltaic performance, even better than the commercial ruthenium complex (N719). This paper reviews the recent significant scientific progress in 10H-phenothiazine-based DSSCs and focuses especially on the relationship between the molecular structure and the photoelectric conversion properties. [ABSTRACT FROM AUTHOR]

Two novel double branched D-π-A organic dyes (DB dyes) are synthesized to investigate the influence of the linkage location in DB dyes on the performance of dye-sensitized solar cells (DSSCs), where phenothiazine is introduced as a donor, thiophene-benzotriazole unit as the π-bridge and cyanoacrylic acid as the electron-acceptor. The photophysical, electrochemical and photovoltaic properties of the dyes are systematically investigated. The results show that the location of the linkage unit has a small effect on the physical and electrochemical properties of the dyes. However, when the dyes are applied in DSSCs, an obvious decline of short-circuit current (Jsc) and open-circuit voltage (Voc) is found by moving the linkage unit from the donor part to the π-bridge part. The DSSC based on the dye DB-D with the linkage unit in the donor obtains an overall power conversion efficiency of 6.13%, which is about 68% higher than that (3.65%) of the DSSC based on the dye DB-B with the linkage unit in the π-bridge. The DB-B based device exhibits a lower efficiency due to its serious aggregation and short electron lifetime. The results indicate that the linkage location of the dyes has a big effect on the performance of the DSSCs. [ABSTRACT FROM AUTHOR]

Four novel D-π-A metal-free organic dyes DTP1-4 containing a dithienopyrrolobenzothiadiazole (DTPBT) unit were synthesized and applied in dye-sensitized solar cells, where DTPBT was employed as a π -spacer for the first time. The photophysical, electrochemical and photovoltaic properties of the dyes were systematically investigated. The dyes DTP1-4 showed broad absorption spectra and high molar extinction coefficient, resulting in high light harvesting efficiency. In addition, the impacts of donors and the thiophene unit as an additional π-spacer were also studied. The results showed that the dye DTP4 with triphenylamine as the donor exhibited better photovoltaic performance than DTP1-3 with phenothiazine as the donor. The linking position of the thiophene unit to the DTPBT unit significantly influenced the photovoltaic performance. A power conversion efficiency of 7.55% with 1 mM CDCA as the co-adsorbent under simulated AM 1.5 G illumination was reached by the DSSC sensitized by the dye DTP4. These results indicate that the DTPBT-based organic dye is a promising candidate for efficient DSSCs. [ABSTRACT FROM AUTHOR]

Natural soiling of photovoltaic (PV) panel is an increasing problem especially in arid and desert areas. Finding a strategy that can reduce dust adhesion on PV panels is highly desirable but remains challenging. In this paper, different wettability of transparent coatings including superhydrophilic, hydrophilic, hydrophobic and superhydrophobic coatings were prepared to investigate the importance of surface roughness and surface energy. Their anti-soiling effects were investigated under different airflow velocity and different tilt angles. Dust deposition density, reduced transmittance, the ratio of reduced transmittance between bare glass surfaces and coatings, and PV efficiency reduction were used to characterize dust resistance performances. It is found that dust adhesion on superhydrophilic coatings was eminently governed by their respective high surface energy, with surface roughness rendering lesser contribution towards resisting/adhering effects. However, for other three coatings, further reducing the surface energy had little influence on the improvement of dust-proof ability. A large airflow velocity is beneficial to resist dust adhesion for all four types of coatings. However, a large airflow velocity has a limited ability to improve the anti-soiling effect of superhydrophilic coating under different tilt angles compared with other three coatings. The anti-soiling coatings can be referred to hydrophilic and hydrophobic coatings, not limited to superhydrophobic coating only. The study provides an invaluable guiding significance for preparation of dust-resistant coatings. • The anti-soiling effects of different wettability of transparent coatings were investigated. • The anti-soiling effects were investigated under different airflow velocity and tilt angle. • Large airflow velocity was beneficial to resist dust adhesion for all four types of coatings. • The anti-soiling effect of superhydrophilic coating was the weakest under different tilt angles. • Surface roughness and surface energy both rendered contribution towards anti-soiling. [ABSTRACT FROM AUTHOR]

Correction for ‘Phenothiazine-based dyes for efficient dye-sensitized solar cells’ by Zu-Sheng Huang et al., J. Mater. Chem. C, 2016, 4, 2404–2426. [ABSTRACT FROM AUTHOR]

• A new near-infrared probe DBT for H 2 S detection was developed. • DBT can detect H 2 S with high selectivity and good sensitivity. • The detection limit of DBT for H 2 S was 6.74 nM. • DBT can be applied in endogenous H 2 S imaging in HCT116 cell with turn-on emission. Hydrogen sulfide (H 2 S) plays a significant role in many pathological and physiological processes in living system. It is of great importance to develop effective fluorescent probes for H 2 S detection with good sensitivity and high selectivity. In this work, we developed a new near-infrared (NIR) fluorescent probe DBT for H 2 S detection with fluorescence turn-on performance. For probe DBT , triphenylamine combined with BODIPY is used as the fluorophore and 2, 4-dinitrophenylsulfonyl group is acted as the reaction site. The results show that DBT exhibits excellent sensing characters toward H 2 S with rapid response (within 150 s), excellent sensitivity (detection limit of 6.74 nM) and good selectivity. Importantly, this probe is also successfully applied in the fluorescent imaging of endogenous H 2 S in HCT116 cells. The outcomes indicate that the probe DBT is a valuable tool for H 2 S detection in solution and living cells. [ABSTRACT FROM AUTHOR]

Bacterial infections are closely correlated with the genesis and progression of cancer, and the elimination of cancer-related bacteria may improve the efficacy of cancer treatment. However, the combinatorial therapy that utilizes two or more chemodrugs will increase potential adverse effects. Image-guided photodynamic therapy is a highly precise and potential therapy to treat tumor and microbial infections. Herein, four donor-acceptor-π-bridge-acceptor (D-A-π-A) featured near-infrared (NIR) aggregation-induced emission luminogens (AIEgens) (TQTPy, TPQTPy, TQTC, and TPQTC) with type I and type II reaction oxygen species (ROS) generation capabilities are synthesized. Notably, TQTPy shows mitochondria targeted capacity, the best ROS production efficiency, long-term tumor retention capacity, and more importantly, the three-in-one fluorescence imaging guided therapy against both tumor and microbial infections. Both in vitro and in vivo results validate that TQTPy performs well in practical biomedical application in terms of NIR-fluorescence imaging-guided photodynamic cancer diagnosis and treatment. Moreover, the amphiphilic and positively charged TQTPy is able to specific and ultrafast discrimination and elimination of Gram-positive (G+) Staphylococcus aureus from Gram-negative (G-) Escherichia coli and normal cells. This investigation provides an instructive way for the construction of three-in-one treatment for image-guided photodynamic cancer therapy and bacteria elimination., (© 2024 Wiley‐VCH GmbH.)

The first example of copper-catalyzed four-component coupling reaction of aryl iodides, Se powder, secondary amines, and maleimides is developed. This reaction provides an efficient and concise route to access aminoarylselenated maleimides via double C-Se bonds and C-N bond formation. The appealing features of this transformation are the use of Se powder as a selenating reagent, a green catalytic system, a wide range of substrate scope, and late-stage selenation of bioactive compounds.

Five novel metal-free organic dyes DQ1-5 containing a dipentyldithieno[3,2-f:2',3'-h]quinoxaline (DPQ) unit were synthesized and applied in dye-sensitized solar cells (DSSCs), where DPQ was employed as a π-spacer for the first time. Their photophysical, electrochemical, and theoretical calculations and photovoltaic properties were systematically investigated. All the five dyes show broad photoresponse. Especially the absorption edges of DQ3-5 extend to 800 nm on the TiO2 films. The inserted electron-rich unit 3,4-ethylenedioxythiophene or electron-withdrawing group benzothiadiazole (BTD) in DPQ-based dyes can greatly influence the optoelectronic properties of the dyes. In addition, the different electron donors also significantly affect the performance of the DSSCs. Under standard global AM 1.5 solar light conditions, the DQ5 sensitized solar cell obtained a power conversion efficiency of 7.12%. The result indicates that the rigid DPQ-based organic dye is a promising candidate for efficient DSSCs.