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In vivo fluorescent imaging in the second near‐infrared window (NIR‐II) provides an excellent approach for understanding the biological processes in substantially scattered tissue environments with reasonable temporal‐spatial resolution. In spite of an enormous amount of organic and inorganic NIR‐II fluorophores developed, there are no reported NIR‐II fluorescent protein. Here, the first NIR‐II fluorescent protein is presented, IRFP1032, which exhibits strong exciton absorption and emission in the NIR‐II region, with exciton extinction coefficient about 4.1 × 106 M−1cm−1 at the excitation maximum 1008 nm, emission maximum of 1032 nm, and emission quantum yield about 0.84%. The IRFP1032 is found to be one of the brightest NIR‐II fluorophores ever reported (brightness of 3.4×104 M−1cm−1 in PBS), thousands‐fold brighter than IR26 in DCM. Furthermore, the IRFP1032 exhibits an ultra‐photostability in comparison to small organic fluorophore. Taking the advantage of the excellent photophysical properties of the NIR‐II fluorescent protein, high‐quality in vivo imaging is realized, for instance, real time observation of blood flow dynamics, dual‐channel imaging of the lymphatic/blood vessel network, and the trajectories of single bacterial cell travelling in blood vessels. The promising NIR‐II in vivo imaging properties demonstrated here with IRPF1032 can open a new scene in fluorescent protein‐based imaging. [ABSTRACT FROM AUTHOR]

Poor operational stability is a crucial factor limiting the further application of perovskite solar cells (PSCs). Organic semiconductor layers can be a powerful means for reinforcing interfaces and inhibiting ion migration. Herein, two hole‐transporting molecules, pDPA‐SFX and mDPA‐SFX, are synthesized with tuned substituent connection sites. The meta‐substituted mDPA‐SFX results in a larger dipole moment, more ordered packing, and better charge mobility than pDPA‐SFX, accompanying with strong interface bonding on perovskite surfaces and suppressed ion motion as well. Importantly, mDPA‐SFX‐based PSCs exhibit an efficiency that has significantly increased from 22.5 % to 24.8 % and a module‐based efficiency of 19.26 % with an active area of 12.95 cm2. The corresponding cell retain 94.8 % of its initial efficiency at maximum power point tracking (MPPT) after 1,000 h (T95=1,000 h). The MPPT T80 lifetime is as long as 2,238 h. This work illustrates that a small degree of structural variation in organic compounds leaves considerable room for developing new HTMs for light stable PSCs. [ABSTRACT FROM AUTHOR]

In recent years, self‐assembled monolayers (SAMs) have been proven to work efficiently as hole‐selective materials in both organic solar cells (OSCs) and perovskite solar cells. Although competitive performances are reported with these materials, a mechanistic understanding on device stability remains elusive. This study reveals that while various SAM molecules can increase the indium tin oxide (ITO) work function versus vacuum, they may not consistently result in monolayers that ensure simultaneous improvement in performance and operational stability of devices. Energetically, achieving alignment between the work function of the SAM‐modified electrode and the ionization energy (IE) of the donor is shown to be crucial for a low hole injection barrier, irrespective of the SAM's IE. Light‐induced degradation in the widely used SAM, (2‐(9H‐carbazol‐9‐yl)ethyl) phosphonic acid (2PACz), is identified through diverse aging tests and comprehensive chemical and electronic characterizations. This degradation involves SAM molecule decomposition and chemical reactions with the photoactive layer, contributing further to device degradation. Addressing these challenges, sputtered nickel oxide/SAM bilayers are proposed as hole‐selective contact with tailored interface energetics for both efficient and photostable OSCs, offering a promising alternative to commonly used hygroscopic PEDOT:PSS in OSCs. [ABSTRACT FROM AUTHOR]

As family members of polycyclic aromatic hydrocarbons, compound anthracene (Ant) and phenanthrene (Phe) as isomers are widely used in organic optical materials and electronic materials. But their photochemical and physical properties are very different. In this work, the room temperature phosphorescence (RTP) properties of PVA−B‐Ant and PVA−B‐Phe are discussed carefully which are prepared by B−O click reaction through polyvinyl alcohol (PVA) with 9‐anthraceneboronic acid (B‐Ant) and 9‐phenanthrenylboronic acid (B‐Phe), respectively. PVA−B‐Phe 1 % film exhibits excellent fluorescence (FL) emission at 374 nm and RTP emission at 523 nm with green afterglow and around 1.9 s phosphorescence lifetime. However, PVA−B‐Ant 1 % film only shows strong blue FL emission at 414 nm, and the emission intensity decreases seriously with the extension of irradiation time. Experimental and theoretical calculations results suggest that the photodimer of Ant which is formed in PVA matrix under the UV light irradiation would be competitive with the process of RTP emission. This work demonstrates that the RTP properties of organic molecules might be probably affected by the photostability of the organic phosphor under UV irradiation. [ABSTRACT FROM AUTHOR]

Lanthanide‐based upconversion molecular complexes have potential application in diverse fields and attracted considerable research interest in recent years. However, the similar coordination reactivity of lanthanide ions has constrained the designability of target molecule with well‐defined structure, and many attempts obtained statistical mixtures. Herein, an ion‐paired Yb−Eu heteronuclear complex [Eu(TpPy)2][Yb(ND)4] (TpPy=tris[3‐(2‐pyridyl)pyrazolyl]hydroborate, ND=3‐cyano‐2‐methyl‐1,5‐naphthyridin‐4‐olate) was designed and synthesized. Thanks to the radius difference between Eu3+ (1.07 Å) and Yb3+ (0.98 Å) ions, the hexadentate TpPy ligand was selected to coordinate with Eu3+ and the Yb3+ with a smaller radius was chelated by bidentate ND ligand. As a result, the sites of Eu3+ and Yb3+ in the complex can be clarified by high‐resolution mass spectrometry and single‐crystal structure analysis. Upon the excitation of Yb3+ at 980 nm, the upconversion emission of Eu3+ was realized through a cooperative sensitization process. Furthermore, [Eu(TpPy)2][Yb(ND)4] demonstrated excellent photostability during continuous high‐power density 980 nm laser irradiation, with a LT95 (the time to 95 % of the initial emission intensity) of 420 minutes. This work provides the first example of a pure ion‐paired Yb−Eu heteronuclear complex upconversion system and may bring insights into rational design of lanthanide‐based upconversion molecular complexes. [ABSTRACT FROM AUTHOR]

This research aims to develop the inclusion complex of 2, 4‐diamino‐6‐hydroxypyrimidine (DHP) with β‐cyclodextrin (β‐CD) using an inclusion process, and to investigate the effect of inclusion on the photo stability and bioactivity of DHP. The formation of DHP‐β‐CD inclusion complex has been examined by means of physicochemical as well as spectroscopic techniques (1H NMR, FT‐IR, PXRD and SEM) suggesting the successful inclusion of the DHP molecule into the β‐CD cavity. The 1 : 1 stoichiometry of the inclusion complex was validated through Job's plot. β‐CD displayed a fairly strong affinity (Ka =889.67 M−1) for DHP, indicating that the binding process is thermodynamically feasible. A molecular docking study speculated the most preferred orientation of DHP molecule within the binding pocket of β‐CD cavity. The photostability of DHP was found to improve on complexation with β‐CD. In vitro antibacterial activity test demonstrated that the DHP‐β‐CD inclusion complex displayed better activity than pure DHP. DHP‐β‐CD inclusion complex (IC50 =240.04 μM) also exhibited relatively significant in vitro cytotoxic activity than pure DHP towards the human kidney cancer cell line (ACHN). These results reveals that the inclusion of DHP using β‐CD could lead to stabilization of DHP and efficient display of its bioactivity. [ABSTRACT FROM AUTHOR]

Overexposure to blue light due to the excessive use of electronic devices has been implicated in premature skin aging and eye damage, among other injuries to health. This study aimed to synthesize two azo derivatives of the 2‐(amino‐2′‐hydroxyphenyl) benzoxazole and explore their potential as UV and blue light filters, proposing a new spectral profile. The synthesis of the heterocyclic compounds involved condensation reactions and diazotation. The derivatives 2‐(benzoxazol‐2‐yl)‐5‐[(2‐hydroxynaphthyl)diazenyl]phenol and 2‐(benzoxazol‐2‐yl)‐4‐[(2‐hydroxynaphthyl)diazenyl]phenol were synthesized with a yield greater than 70%. Solubility was evaluated in seven different solvents. The maximum absorption wavelengths (λmax) were determined using UV–Vis scanning spectrophotometry in the range of 200–600 nm. Photostability was assessed using a solar simulator and the Sun protection factor (SPF) was determined using in vitro methodology. Cytotoxicity was evaluated using the MTT assay in V79 cells. These compounds were able to absorb UVA, UVB, and blue light, with λmax ranging from 300 to 500 nm and demonstrated photostability after 3 h of exposure to solar simulator with an SPF higher than 45. The compounds exhibited solubility in all lipophilic solvents tested. Regarding cytotoxicity, IC50 values were comparable to other filters. These findings indicate that both compounds hold promise as potential organic filters. [ABSTRACT FROM AUTHOR]

Recently, giant quantum dots (g‐QDs) with a core/interface graded alloy shell/shell structure have shown promise in reducing photoluminescence (PL) intermittency and improving photostability. However, this approach has been mainly demonstrated with red and green emitting g‐QDs but the blue‐emitting graded alloy QDs has remained less explored. To tackle this challenge, a composition gradient method is employed to create three blue‐emitting CdZnS/CdxZn1–xS/ZnS core/interface graded alloy shell/shell (C/A/S) quantum dots (QDs) with different diameters. The sample with the largest diameter (gQD‐3) exhibits superior optical characteristics, with a photoluminescence quantum yield (PLQY) of approximately 62% and around 80% ON/radiative events at the single‐particle level. Conversely, the smallest diameter (gQD‐1) sample shows lower PLQY and only 30% radiative events with longer OFF/nonradiative events. Probability distribution analysis of PL trajectories, fitted with a truncated power law, reveals a significantly higher carrier de‐trapping rate in gQD‐3 compared to gQD‐1, attributed to its proximity to band edge trap states. Additionally, the largest diameter sample retains remarkable optical performance during 48 h of continuous UV irradiation in colloidal suspension and single‐particle levels. These findings show optimized core/shell structures, gradual alloy interfaces, and outer shell coatings can stabilize blue‐emitting quantum dots, advancing next‐gen optoelectronics. [ABSTRACT FROM AUTHOR]

Large voltage deficit and photoinduced halide segregation are the two primary challenges that hinder the advancement of wide‐bandgap (WBG) (Eg ≥ 1.65 eV) perovskite solar cells (PSCs). Herein, a cation engineering approach to enhance the optoelectronic properties of formamidine–cesium (FA‐Cs) WBG perovskites by incorporating methylamine (MA) as the third cation is presented. Three perovskite species with a bandgap of 1.68 eV, abbreviated as Cs0.05, Cs0.15, and Cs0.25, are systematically studied by optimizing the MA content. The incorporation of MA is found to effectively enhance the crystallinity and improve the carrier lifetimes of the three perovskite species. Moreover, the microstrain in the FA‐MA‐Cs perovskite films is significantly reduced due to the buffer effect of MA between the size‐mismatched FA and Cs, a benefit derived from the cascade cation design. The optimized compositions for the three species are Cs0.05MA0.2FA0.75PbI2.58Br0.42, Cs0.15MA0.1FA0.75PbI2.68Br0.32, and Cs0.25MA0.03FA0.72PbI2.73Br0.27, respectively. Among these, Cs0.25MA0.03FA0.72PbI2.73Br0.27 perovskite stands out due to its high crystallinity, low microstrain, and low trap density, giving rise to the highest efficiency of 20.64% with the lowest voltage loss. This perovskite also exhibits superior air, light, and thermal stability. These findings underscore the importance of rational cation design in achieving efficient and photostable WBG PSCs. [ABSTRACT FROM AUTHOR]

Perovskite solar cells (PSCs) have witnessed a meteoric rise in device performance. However, maintaining photostability, particularly under thermal stress, remains a challenge due to defect formation in the perovskite layer. This study introduces europium (III) trifluoromethanesulfonate [Eu(OTF)3] as a multifunctional additive in two‐step processed perovskite films, significantly improving the performance and high‐temperature photostability of n‐i‐p PSCs. Density function theory (DFT) calculations reveal that the OTF− anion strongly coordinates with Pb2+, effectively inhibiting iodine vacancy defect formation. The addition of Eu(OTF)3 promotes perovskite grain growth to ≈2 µm and enhances film crystallinity. PSCs with a structure of ITO/SnO2/perovskite/PDCBT/NiOx/Au achieve a champion power conversion efficiency (PCE) of 23.8%. Under 85 ± 5 °C and 1 sun illumination at an open circuit in ambient air, the PSCs with Eu(OTF)3 retain 82% of their initial PCE after aging for 1500 h. [ABSTRACT FROM AUTHOR]

Quantum dot (QD)‐based luminescent solar concentrators (LSCs) promise to revolutionize solar energy technology by replacing building materials with energy‐harvesting devices. However, QDs degrade under air, limiting the long‐term performance of QD‐LSCs. This study introduces an innovative approach to prevent QDs degradation by utilizing a photoactive polymer matrix (maleic anhydride‐grafted poly(styrene‐b‐ethylene‐co‐butylene‐b‐styrene, SEBS‐g‐MA). This strategy has been tested outdoors over a 2‐year period on five LSCs, followed by characterization of the weathered devices. The tested LSCs consist of three QD‐LSCs (CuInS2/ZnS, InP/ZnSe/ZnS, CdSe/CdS/ZnS core/shell QDs), alongside a Lumogen dye‐based LSC and a luminophore‐free LSC. The study yields several findings: 1) SEBS‐g‐MA undergoes photochemistry outdoors, 2) SEBS‐g‐MA accelerates the photodegradation of Lumogen, 3) the power conversion efficiency of CdSe‐based QD‐LSC drops by 80% due to reduction of the photoluminescence quantum yield, and 4) under illumination SEBS‐g‐MA protects CuInS2 and InP‐based QDs from degradation, ensuring a stable performance during the entire study. This work thus demonstrates for the first time that the interaction between the luminophores and the matrix is a critical determinant of the long‐term success of LSCs. Leveraging on the fact that this is the longest outdoor study to date, we propose design rules for highly efficient and stable QD‐LSCs. [ABSTRACT FROM AUTHOR]

For the use of polymeric electrochromic devices (ECDs) in architectural or automotive applications, the photostability of the electrochromic (EC) polymer is crucial for long‐term durability. In this study, the photostability of the side‐chain modified poly(3,4‐ethylenedioxythiophene) (PEDOT‐EthC6)thin films deposited by roll‐to‐roll slot‐die coating on indium tin oxide coated polyethylene terephtalate (PET‐ITO) is investigated and characterized by UV–vis and IR spectroscopy. Residual iron salt on the EC polymer layer, necessary for the in situ polymerization, and the variation of storage times between processing steps have no influence on the degradation rate during light exposure. The photostability of the thin films is 30% better in an inert atmosphere than in ambient conditions. Different long‐pass filters are applied to enhance the photostability in the colored and the bleached state. The position of the absorption edge strongly affects the photostability and visual appearance/color of the PEDOT‐EthC6 electrodes. The analysis of the CIE L*a*b* color coordinates reveals that a trade‐off between stability and a desirable color is necessary. To prevent UV degradation of the EC polymer in flexible ECDs, sputtered nickel oxide is chosen as the counter electrode material. The hybrid ECD shows no sign of degradation and loss of electrochromic performance after 350 h of light exposure. [ABSTRACT FROM AUTHOR]

The development and use of interface materials are essential to the continued advancement of organic solar cells (OSCs) performance. Self‐assembled monolayer (SAM) materials have drawn attention because of their simple structure and affordable price. Due to their unique properties, they may be used in inverted devices as a modification layer for modifying ZnO or as a hole transport layer (HTL) in place of typical poly(3,4‐ethylenedioxythiophene)‐poly(styrenesulfonate) (PEDOT:PSS) in conventional devices. In this work, zinc oxide (ZnO) is modified using five structurally similar SAM materials. This resulted in a smoother surface, a decrease in work function, a suppression of charge recombination, and an increase in device efficiency and photostability. In addition, they can introduced asfor hole extraction layer between the active layer and MoO3, enabling the use of the same material at several functional layers in the same device. Through systematic orthogonal evaluation, it is shown that some SAM/active layer/SAM combinations still offered device efficiencies comparable to ZnO/SAM, but with improved device' photostability. This study may provide recommendations for future SAM material's design and development as well as a strategy for boosting device performance by using the same material across both sides of the photoactive layer in OSCs. [ABSTRACT FROM AUTHOR]

Organic photovoltaics (OPVs) show great promise for both outdoor and indoor applications. However, there remains a lack of understanding around the stability of OPVs, particularly for indoor applications. In this work, the photostability of the poly[(thiophene)‐alt‐(6,7‐difluoro‐2‐(2‐hexyldecyloxy)quinoxaline)]:2,2′‐((2Z,2′Z)‐((4,4,9,9‐tetrahexyl‐4,9‐dihydro‐s‐indaceno[1,2‐b:5,6‐b′]dithiophene‐2,7‐diyl)bis(methanylylidene))bis(3‐oxo‐2,3‐dihydro‐1H‐indene‐2,1‐diylidene))dimalononitrile blend is investigated for both outdoor and indoor applications. Photostability is found to vary drastically with illumination intensity. Devices under high‐intensity white light‐emitting diode (LED) illumination, with their short‐circuit current density (JSC) matching JSC–EQE for AM1.5 G illumination, lose 42% of their initial performance after 30 days of illumination. Contrastingly, after almost 47 days of illumination devices under 1000 lux white LED illumination show no loss in performance. The poor photostability under 1 sun illumination is linked to the poor photostability of IDIC. Through Raman spectroscopy and mass spectrometry, IDIC is found to suffer from photoisomerization, which detrimentally impacts light absorption and carrier extraction. In this work, it is highlighted that under low light levels, the requirement of intrinsic material photostability may be less stringent. [ABSTRACT FROM AUTHOR]

Single‐molecule localization microscopy has proved promising to unravel the dynamics and molecular architecture of thin biological samples down to nanoscales. For applications in complex, thick biological tissues shifting single‐particle emission wavelengths to the shortwave infrared (SWIR also called NIR II) region between 900 to 2100 nm, where biological tissues are more transparent is key. To date, mainly single‐walled carbon nanotubes (SWCNTs) enable such applications, but they are inherently 1D objects. Here, 0D ultra‐small luminescent gold nanoclusters (AuNCs, <3 nm) and ≈25 nm AuNC‐loaded‐polymeric particles that can be detected at the single‐particle level in the SWIR are presented. Thanks to high brightness and excellent photostability, it is shown that the dynamics of the spherical polymeric particles can be followed at the single‐particle level in solution at video rates for minutes. We compared single particle tracking of AuNC‐loaded‐polymeric particles with that of SWCNT diffusing in agarose gels demonstrating the specificity and complementarity of diffusion properties of these SWIR‐emitting nano‐objects when exploring a complex environment. This extends the library of photostable SWIR emitting nanomaterials to 0D nano‐objects of variable size for single‐molecule localization microscopy in the second biological window, opening unprecedented possibilities for mapping the structure and dynamics of complex biological systems. [ABSTRACT FROM AUTHOR]

Designing plasmonic nanoparticles for biomedical photoacoustic (PA) imaging involves tailoring material properties at the nanometer scale. A key in developing plasmonic PA contrast nanoagents is to engineer their enhanced optical responses in the near‐infrared wavelength range, as well as heat transfer properties and photostability. This study introduces anisotropic plasmonic nanosphere aggregates with close interparticle proximity as photostable and efficient contrast agents for PA imaging. Silver (Ag) is particularly attractive because it has the strongest optical response and highest heat conductivity among plasmonic metals. The results demonstrate that close interparticle proximity in silver nanoaggregates (AgNAs), spatially confined within a polymer shell layer, leads to blackbody‐like optical absorption, resulting in robust PA signals through efficient pulsed heat generation and transfer. Additionally, the AgNAs exhibit a high photodamage threshold highlighting their potential to outperform conventional plasmonic contrast agents for high‐contrast PA imaging over multiple imaging sessions. Furthermore, the capability of the AgNAs are demonstrated for molecular PA cancer imaging in vivo by incorporating a tumor‐targeting peptide moiety. [ABSTRACT FROM AUTHOR]

We report a family of donor‐acceptor thermally activated delayed fluorescent (TADF) compounds based on derivatives of DMAC‐TRZ, that are strongly photoreducing. Both Eox and thus E*ox could be tuned via substitution of the DMAC donor with a Hammett series of p‐substituted phenyl moieties while Ered remained effectively constant. These compounds were assessed in the photoinduced dehalogenation of aryl halides, and analogues bearing electron withdrawing groups were found to produce the highest yields. Substrates of up to Ered=−2.72 V could be dehalogenated at low PC loading (1 mol %) and under air, conditions much milder than previously reported for this reaction. Spectroscopic and chemical studies demonstrate that all PCs, including literature reference PCs, photodegrade, and that it is these photodegradation products that are responsible for the reactivity. [ABSTRACT FROM AUTHOR]

Although organic solar cells (OSCs) have received increasing attention because of their high device efficiencies, the fundamental mechanism governing their photostability remains elusive. Herein, the effect of the luminescence stability of the acceptor components on the burn‐in voltage loss of binary and ternary OSCs is demonstrated. A systematic characterization reveals that the acceptor component experiences an abnormal decrease in luminescence under photoaging—specifically, photoinduced luminescence quenching—because of a photoinduced conformational change. This phenomenon increases nonradiative recombination in blends and thus causes a substantial nonradiative voltage loss of OSCs. Moreover, an introduction of a third component with high luminescence stability can effectively reduce the burn‐in voltage loss of OSCs. A composition‐dependent photostability study of the resultant ternary OSCs reveals that the reduction in the burn‐in voltage loss of OSCs is mainly driven by the third component distributed in the mixed phase; high luminescence stability of this component effectively prevents the increase in nonradiative voltage loss by photoaging. The results suggest that improving the luminescence stability of the acceptor components can be an effective method for highly stable photovoltaics with greatly reduced burn‐in voltage loss. [ABSTRACT FROM AUTHOR]

High‐resolution spatio‐temporal monitoring of the cell membrane lipid order provides visual insights into the complex and sophisticated systems that control cellular physiological functions. Solvatochromic fluorescent probes are highly promising noninvasive visualization tools for identifying the ordering of the microenvironment of plasma membrane microdomains. However, conventional probes, although capable of structural analysis, lack the necessary long‐term photostability required for live imaging at the cellular level. Here, an ultra‐high‐light‐resistant solvatochromic fluorescence probe, 2‐N,N‐diethylamino‐7‐(4‐methoxycarbonylphenyl)‐9,9‐dimethylfluorene (FπCM) is reported, which enables live lipid order imaging of cell division. This probe and its derivatives exhibit sufficient fluorescence wavelengths, brightness, polarity responsiveness, low phototoxicity, and remarkable photostability under physiological conditions compared to conventional solvatochromic probes. Therefore, these probes have the potential to overcome the limitations of fluorescence microscopy, particularly those associated with photobleaching. FπCM probes can serve as valuable tools for elucidating mechanisms of cellular processes at the bio‐membrane level. [ABSTRACT FROM AUTHOR]

Achieving environmentally friendly solvent-processed high-performance organic photovoltaic cells (OPVs) is a crucial step toward their commercialization. Currently, OPVs with competitive efficiencies rely heavily on harmful halogenated solvent additives. Herein, the green and low-cost 9-fluorenone (9-FL) is employed as a solid additive. By using the o-xylene/9-FL solvent system, the PM6:BTP-eC9-based devices deliver power-conversion efficiencies of 18.6% and 17.9% via spin-coating and blade-coating respectively, outperforming all PM6:Y-series binary devices with green solvents. It is found that the addition of 9-FL can regulate the molecular assembly of both PM6 and BTP-eC9 in film-formation (molecule-level mixing) and post-annealing (thermal-assisted molecular reorganization with additive volatilization) stages, so as to optimize the blend morphology. As a result, the charge transport ability of donor and acceptor phases are simultaneously enhanced, and the trap-assisted recombination is reduced, which contributes to the higher short-circuit current density and fill factor. Moreover, the generation of photo-induced traps is significantly suppressed, resulting in improved stability under illumination. It is further demonstrated the excellent universality of 9-FL in various photoactive systems, making it a promising strategy to advance the development of eco-friendly OPVs. [ABSTRACT FROM AUTHOR]

The perovskite/silicon tandem solar cell (TSC) has attracted tremendous attention due to its potential to breakthrough the theoretical efficiency set for single‐junction solar cells. However, the perovskite solar cell (PSC) designed as its top component cell suffers from severe photo‐induced halide segregation owing to its mixed‐halide strategy for achieving desirable wide‐bandgap (1.68 eV). Developing pure‐iodide wide‐bandgap perovskites is a promising route to fabricate photostable perovskite/silicon TSCs. Here, we report efficient and photostable pure‐iodide wide‐bandgap PSCs made from an anti‐solvent‐free (ASF) technique. The ASF process is achieved by mixing two precursor solutions, both of which are capable of depositing corresponding perovskite films without involving anti‐solvent. The mixed solution finally forms Cs0.3DMA0.2MA0.5PbI3 perovskite film with a bandgap of 1.68 eV. Furthermore, methylammonium chloride additive is applied to enhance the crystallinity and reduce the trap density of perovskite films. As a result, the pure‐iodide wide‐bandgap PSC delivers efficiency as high as 21.30 % with excellent photostability, the highest for this type of solar cells. The ASF method significantly improves the device reproducibility as compared with devices made from other anti‐solvent methods. Our findings provide a novel recipe to prepare efficient and photostable wide‐bandgap PSCs. [ABSTRACT FROM AUTHOR]

Electron shuttles are pivotal in enhancing the conversion efficiency at the biotic‐abiotic interface within microbial photoelectrochemical systems. Nevertheless, the potentially toxic effects of electron shuttles on microbial cells and their instability when exposed to light are often overlooked. This concept highlights the attention paid to electron shuttles in microbial photoelectrochemical systems, such as the cytotoxicity, the photoexcited state, and the photostability. Furthermore, it offers theoretical guidance for selecting electron shuttles to optimize sustainable energy production and environmental remediation. [ABSTRACT FROM AUTHOR]

Introduction: Sennosides are the main active constituents of the dried leaves and/or pods of Senna alexandrina Mill. that are used as laxatives. A hypothesis is that aglycones are formed during the degradation of sennosides. However, it is unknown, whether this happens under visible light exposure and how photosensitive sennosides behave in solution. Objectives: Pure anthraquinone glycosides were tested on their behaviour during sample preparation in the lab under visible light exposure in dependence on the instability of the solvent. Materials and methods: Samples before and after exposure were analysed using UHPLC with UV/Vis and MS detection. Results: Under visible light protection, the solutions were stable for 14 days at room temperature whereas a loss of 20%–60% was measured after 1 day of light exposure. The loss of sennosides due to degradation can be as fast as up to 2%–2.5% per hour, which might have a tremendous impact on phytochemical analysis results during the course of an analysis. The formation of aglycones was not observed in the degradation of sennosides and rhein‐8‐O‐glucoside. Conclusion: Aglycones could not be found as a result of the forced degradation. The solutions of sennosides clearly need to be protected from light to obtain reliable analytical results, and light protection is a major point for the stability of liquid preparations. Sennosides are the main active constituents of leaves and pods of Senna alexandrina Mill., used as laxatives. Light‐induced degradation of sennoside references during analysis is yet unknown. Samples before and after exposure were analysed using UHPLC‐UV/Vis/MS. Under light protection, the solutions were stable for 14 days, whereas a loss of 20%−60% after 1 day of visible light exposure was observed. The degradation rate ranged between 2% and 2.5%/h. Formation of aglycones was not observed during degradation of sennosides and rhein‐8‐O‐glucoside. [ABSTRACT FROM AUTHOR]

The pulmonary vascular system plays a crucial role in maintaining normal physiological functions, and perturbations in this network often serve as indicators for various fatal diseases. Thus, accurate mapping and assessment of the intricate anatomical details of pulmonary vasculature is essential for the investigation of the underlying mechanism of these diseases. Yet it is considered a tough challenge as traditional imaging techniques offer limited representations of the vasculature network in the lung, while optical imaging methods face limitations from tissue depth. To overcome these obstacles, in this study, an AIENP‐reinforced DISCO method, for whole‐tissue 3D reconstruction of pulmonary capillaries is presented. Combining AIENPs, hydrogel‐enhanced scaffolds, and solvent‐based DISCO procedures, the method successfully visualizes the entire network of mouse pulmonary capillaries with a significantly shortened timeframe and cost. The whole process including labeling and clearing takes 6 days and it costs ≈ 5 USD to stain the lung vasculature of an adult mouse. Moreover, the study provides valuable insights for detecting pulmonary vascular abnormalities. This fast and cost‐effective technique opens new avenues for developing better fluorophores compatible with tissue optical clearing and offers insights for in‐depth research on pulmonary pathophysiology. [ABSTRACT FROM AUTHOR]

Wide‐bandgap (WBG) perovskite solar cells (PSCs) have been widely used as the top cell of tandem solar cells. However, photoinduced phase segregation and high open‐circuit voltage loss pose significant obstacles to the development of WBG PSCs. Here, a two‐step small‐size A‐site and large‐size X‐site incorporation strategy is reported to modulate the lattice distortion and improve the film quality of WBG formamidinium‐methylammonium (FAMA) perovskite films for photostable PSCs based on two‐step deposition method. First, CsI with content of 0–20% is introduced to tune the lattice distortion and film quality of FAMA perovskite with a bandgap of 1.70 eV. Then, 4% RbI is incorporated to further modulate the perovskite growth and lattice distortion, leading to the suppression of photoinduced phase segregation in the resultant RbCsFAMA quadruple cation perovskites. As a result, the 20%CsI/4%RbI‐doped device obtains a promising efficiency of 20.6%, and the corresponding perovskite film shows good photothermal stability. Even without encapsulation, the device can maintain 92% of its initial efficiency after 1000 h of continuous operation under 1 sun equivalent white light‐emitting diode illumination. [ABSTRACT FROM AUTHOR]

Prolonged ultraviolet exposure results in the formation of cyclobutane pyrimidine dimers (CPDs) in RNA. Consequently, prebiotic photolesion repair mechanisms should have played an important role in the maintenance of the structural integrity of primitive nucleic acids. 2,6‐Diaminopurine is a prebiotic nucleobase that repairs CPDs with high efficiency when incorporated into polymers. We investigate the electronic deactivation pathways of 2,6‐diaminopurine‐2′‐deoxyribose and 9‐methyl‐2,6‐diaminopurine in acetonitrile and aqueous solution to shed light on the photophysical and excited state properties of the 2,6‐diaminopurine chromophore. Evidence is presented that both are photostable compounds exhibiting similar deactivation mechanisms upon the population of the S1(ππ* La) state at 290 nm. The mechanism involves deactivation through the C2‐ and C6‐reaction coordinates and >99% of the excited state population decays through nonradiative pathways involving two conical intersections with the ground state. The radiative and nonradiative lifetimes are longer in aqueous solution compared to acetonitrile. While τ1 is similar in both derivatives, τ2 is ca. 1.5‐fold longer in 2,6‐diaminopurine‐2′‐deoxyribose due to a more efficient trapping in the S1(ππ* La) minimum. Therefore, 2,6‐diaminopurine could have accumulated in significant quantities during prebiotic times to be incorporated into non‐canonical RNA and play a significant role in its photoprotection. [ABSTRACT FROM AUTHOR]

A new approach to the synthesis of derivatives of the perchlorinated tritryl radical is described. It relies on the fact that, under the conditions required to fully chlorinate the ortho positions of a triarylmethane, there is only minimal substitution of aryl fluorine by chlorine and then on the fact that, in the mixed Cl/F substituted triarylmethanes obtained, it is possible to selectively substitute the fluorine‐bearing positions using the sodium salt of n‐hexanol in n‐hexanol/dimethylsulfoxide. The meta‐hexyloxy derivatives obtained are much more soluble and photostable than the parent perchlorotrityl radical. For example, the introduction of four meta‐hexyloxy substituents gives a radical where, under white light illumination, the lifetime is improved by a factor of almost 104. The photostability of the radical, the lifetime of the excited state and the fluorescence all decrease as the number of meta‐hexyloxy substituents is increased. The improvements in solubility and in photostability observed should help in creating a more diverse range of perchlorotrityl radical derivatives and in the development of new applications. [ABSTRACT FROM AUTHOR]

With the rapid increase in power conversion efficiency of organic photovoltaics due to the development of non‐fullerene acceptors (NFAs), prolonging the operational lifetime of devices becomes one of the critical prerequisites for commercial application. In this work, the degradation pathways of a wide range of state‐of‐the‐art NFA molecules via multiple spectroscopic techniques combined with density functional theory and molecular dynamics simulation are revealed. The structural confinement and molecular ordering are responsible for molecular conformational stability under illumination. More importantly, a very general trend is revealed that the origin of increased nonradiative decay under illumination is predominately in the aggregated states with strong intermolecular interactions while the intramolecular exciton dynamics are stable. The increased nonradiative decay correlates with reduced exciton diffusion length. This work provides vital information toward the design of intrinsically photo‐stable NFAs at the molecular level and the importance of aggregation control toward long‐term stable organic solar cells. [ABSTRACT FROM AUTHOR]

Photo‐induced halide segregation in wide‐bandgap (WBG) perovskite leads to poor stability and limits its application in high‐efficiency tandem solar cells. Here, a simple solution strategy to achieve photostable WBG perovskite solar cells (PSCs) with bandgap of ≈1.67 eV by ionic coupling potassium sorbate with defects at the buried perovskite interface is reported. Moreover, the ionic coupled potassium sorbate (ICPS) enables to control the formation of N‐methyl formamidinium ions that can selectively passivate the perovskite defects at grain boundaries. As a result, the photo‐induced halide segregation in the target perovskite films is frozen under intense light. The target single‐junction WBG PSC achieves a record efficiency of 22.00% with an open‐circuit voltage (VOC) of 1.272 V and photostability of less than 2% decay over 2000 h of operation. Perovskite/Silicon tandem solar cells are also fabricated that achieve an efficiency of 30.72% (certified 30.09% @1.087 cm2), which is the highest efficiency reported to date with a tunneling oxide passivating contact (TOPCon) c‐Si substrate. The encapsulated tandem device can maintain 97% of its initial efficiency after 1000 h of operation. [ABSTRACT FROM AUTHOR]

Nickel oxide (NiOX) is a desirable hole‐transporting material for perovskite solar cells owing to their merits of low‐cost, stable, and readily scalable. However, the NiOX|perovskite interface suffers from serious recombination and poor photostability because of the interfacial redox reactions. Herein, NiOX nanoparticles with tunable size have been synthesized at low temperatures by controlling the reactivity of the hydrolysis reaction. A self‐assembled monolayer composed of a ruthenium complex, i.e., C106, is then introduced to optimize the interfacial properties. The C106 molecule chemically bonds to NiOX via carboxyl acid group, which passivates the surface defects of NiOX and suppresses the negative redox reaction at the interface. The modification leads to an improvement in perovskite film morphology, crystallization, and band alignment. As a result, the efficiency of solar cells has been improved from 18.1% to 20.5%. More importantly, the modified solar cells retain >80% of their initial performance after continuous operation under 100 mW cm−2 irradiation for 800 h, which is much enhanced than the unmodified devices. [ABSTRACT FROM AUTHOR]

Lanthanides have unique photoluminescence (PL) emission properties, including very long PL lifetimes. This makes them ideal for biological imaging applications, especially using PL lifetime imaging microscopy (PLIM). PLIM is an inherently multidimensional technique with exceptional advantages for quantitative biological imaging. Unfortunately, due to the required prolonged acquisitions times, photobleaching of lanthanide PL emission currently constitutes one of the main drawbacks of PLIM. In this study, we report a small aqueous‐soluble, lanthanide antenna, 8‐methoxy‐2‐oxo‐1,2,4,5‐tetrahydrocyclopenta[de]quinoline‐3‐phosphonic acid, PAnt, specifically designed to dynamically interact with lanthanide ions, serving as exchangeable dye aimed at mitigating photobleaching in PLIM microscopy in cellulo. Thus, self‐assembled lanthanide complexes that may be photobleached during image acquisition are continuously replenished by intact lanthanide antennas from a large reservoir. Remarkably, our self‐assembled lanthanide complex clearly demonstrated a significant reduction of PL photobleaching when compared to well‐established lanthanide cryptates, used for bioimaging. This concept of exchangeable lanthanide antennas opens new possibilities for quantitative PLIM bioimaging. [ABSTRACT FROM AUTHOR]

The photooxidative stability of a series of doubly bridged anthracenes was evaluated after their preparation via twofold macrocyclization of a bis(resorcinyl)anthracene. Lightfastness correlates with the energy levels of the highest occupied molecular orbital (HOMO), resulting in superior stability of the tetraesters compared to the tetraethers. The lengths and steric demand of the linker only plays a minor role for the ester‐based compounds, which can be prepared in reasonable yields and thus tested in proof‐of‐concept organic light‐emitting diodes. Double ester‐bridging allows deep blue electro‐luminescence, highlighting the importance of the choice of the functional groups used for macrocyclization. [ABSTRACT FROM AUTHOR]

This research delvedinto the BrilliantBlue FCF (BB) dye encapsulation within the nano hydrophobic cavity of β‐cyclodextrin (β‐CD) utilizing various spectroscopic and physicochemical techniques. Job's plot using UV‐visible and Fluorescence spectroscopy, surface tension, and conductance study confirmed 1 : 1 stoichiometry of theinclusion complex (BBIC).1H NMR and FT‐IR studies demonstrated the possible binding mode of BB into the β‐CD cavity, which wasin good agreement withthe DFT study. The degree of affinity of β‐CD for BB in the ground state and excited state were estimatedfromUV‐visible andFluorescence spectroscopy(binding constant=8113.9451 M−1and10199.563 M−1), andthe negative free binding energyshowedthe encapsulation process to bethermodynamically feasible. PXRD analysis and SEM image studies revealed the formation of the BBIC. After complexation with β‐CD, the photostability of BB was found to be enhanced. The interaction study of BB and BBIC with CT‐DNA revealed the sustained release of BB from the complex. Furthermore, neither BBICnor free BB exhibited a significant cytotoxic effect on the normal cell line HEK‐293. However, BBIC complex (IC50=6.15 μM) showed significant in vitrocytotoxic activity compared to pure BB (IC50=8.90 μM) towards cancer cell line A549. [ABSTRACT FROM AUTHOR]

Fluorescent probes are essential for single‐molecule imaging. However, their application in biological systems is often limited by the short photobleaching lifetime. To overcome this, we developed a novel thiolation strategy for squaraine dyes. By introducing thiolation of the central cyclobutene of squaraine (thio‐squaraine), we observed a ≈5‐fold increase in photobleaching lifetime. Our single‐molecule data analysis attributes this improvement to improved photostability resulting from thiolation. Interestingly, bulk measurements show rapid oxidation of thio‐squaraine to its oxo‐analogue under irradiation, giving the perception of inferior photostability. This discrepancy between bulk and single‐molecule environments can be ascribed to the factors in the latter, including larger intermolecular distances and restricted mobility, which reduce the interactions between a fluorophore and reactive oxygen species produced by other fluorophores, ultimately impacting photobleaching and photoconversion rate. We demonstrate the remarkable performance of thio‐squaraine probes in various imaging buffers, such as glucose oxidase with catalase (GLOX) and GLOX+trolox. We successfully employed these photostable probes for single‐molecule tracking of CD56 membrane protein and monitoring mitochondria movements in live neurons. CD56 tracking revealed distinct motion states and the corresponding protein fractions. This investigation is expected to propel the development of single‐molecule imaging probes, particularly in scenarios where bulk measurements show suboptimal performance. [ABSTRACT FROM AUTHOR]

Theoretical study of the photophysical/photochemical properties of 1H‐benzimidazole and its derivatives was carried out using APFD, B3LYP, CAM‐B3LYP and PBE0 density functionals with 6‐311+G(2d,p) basis set. The effects of ethanol, 1,4‐dioxane, acetonitrile and water was investigated by means of Integral Equation Formalism of the Polarizable Continuum Model (IEPCM) in the framework of Self‐Consistent Reaction Field (SCRF). The results obtained show that S2 state of the 1H‐benzimidazole molecule is more acidic than the S0 state as the N5−H11 bond length increased to ~ 1.01 Å. At B3LYP/6‐311+G(2d,p) level of theory, the excitation energy of 1H‐bensimidazole molecule in ethanol from S0 to the S2 state was calculated to be 273 nm (4.54 eV). The electronic energy for this transition was calculated to be 0.131 a.u. and observed to occur between π→π* orbitals. Calculations with the PBE0, APFD and B3LYP functionals reproduced the experimental dipole moment in 1,4‐dioxane, with values of 4.09, 4.09 and 4.07 Debye respectively. However, the dipole moments of the 2‐ethyl‐7‐nitro‐5‐substituted‐1H‐benzimidazoles were calculated to be higher for electron donating groups (EDGs) than those bearing electron withdrawing groups (EWGs). In addition, the molecular polarizability was observed to increase with decreasing energy gap. Local excitation (LE) and charge‐transfer (CT) were observed to mediate the mechanisms of electronic excitation in 2‐ethyl‐7‐nitro‐5‐substituted‐1H‐benzimidazoles. [ABSTRACT FROM AUTHOR]

Microcavity resonance is an effective technique for making promising semitransparent organic photovoltaics (ST‐OPVs) even more aesthetically attractive with high color saturation, by tailoring the visible transmittance spectrum to narrow the transmission peak. In this study, a distinctive microcavity resonance color filter (CF) structure of silver/ bismuth(III) fluoride /silver (Ag/BiF3/Ag) is integrated upon the rear transparent electrode, which simultaneously achieves high color purity and high power conversion efficiency (PCE) for colorful OPVs. By precisely regulating the thickness of the BiF3 layer, colorful OPVs with a wide color gamut and high color purity are achieved, including the colors of indigo, blue, bluish‐green, green, orange, and red, as well as compound color devices with dual or multiple transmission peaks in the visible region. A recorded PCE of 16.27% is obtained for the indigo OPV, with the Commission Internationale de l´Eclairage 1931 coordinates of (0.164 and 0.087) and a maximum transmittance of 18.7% at the transmission peak wavelength of 393 nm. Furthermore, colorful OPVs as color reflectors are systematically investigated under different light incident surfaces. The improved stability of colorful OPVs is attributed to the excellent moisture resistance of BiF3. The colorful OPVs with desired transmitted/reflected colors, and wide color gamut show great potential for future energy harvesting solutions. [ABSTRACT FROM AUTHOR]

Quenching singlet oxygen is the key to improve photostability of fluorescent dyes. We have systematically studied the capability of a new singlet oxygen quencher, DABCOnium (an alkylated derivative of 1,4‐diazabicyclo[2.2.2] octane) on removing singlet oxygen. Results showed that DABCOnium can significantly enhancing photostability of fluorescent thin films for more than 4.3 times compared with that without DABCOnium. After 2 hours of continuous irradiation, fluorescent film doped with DABCOnium retained 90 % of its original fluorescence intensity, which paves a new way in designing high performance singlet oxygen quenchers. [ABSTRACT FROM AUTHOR]

Inorganic glasses doped with luminescent silver clusters are promising materials for photonic applications as white light generation, optical data storage, and spectral conversion. This work reports the photostability study of luminescent silver clusters dispersed in silica‐based glass under continuous ultraviolet irradiation. The photobleaching process model is proposed and the quantum yield of photobleaching is derived from the experimental data. The proposed mechanism of photobleaching is photoionization of silver clusters. Degradation of cluster luminescence is reversible and restores after the heat treatment, indicating the possibility to release trapped electrons and return the initial charge state of clusters. The effect of heat treatment temperature on the luminescence restoration is studied, the amount of restored luminescent clusters depends linearly on the heat treatment temperature. [ABSTRACT FROM AUTHOR]

Titanium dioxide (TiO2) has a strong oxidation effect when absorbing ultraviolet light. Therefore, when TiO2 is used as a light stabilizer in polyvinyl chloride (PVC), it will cause the photodegradation of PVC. Herein, carbon quantum dots (CQDs) coated TiO2 composite (TiO2@CQDs) was prepared by a one‐step hydrothermal method. The prepared TiO2@CQDs were characterized by transmission electron microscopy (TEM), UV–Vis spectroscopy, X‐ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and X‐ray diffraction (XRD). The photostability of PVC film containing TiO2@CQDs was investigated via photodegradation conductivity test, weight loss rate test, and ultraviolet aging test. Due to the down‐conversion effect of CQDs under ultraviolet light, its existence can alleviate the photoaging of PVC. In addition, the thermal stability of PVC containing TiO2@CQDs was studied by conductivity tests and oven thermal aging tests. The presence of CQDs significantly improved the thermal stability of PVC. Meanwhile, the HCl absorption capacity of CQDs could reach 30.8 mg/gcat. According to the DFT calculations, this high absorption capacity is attributed to the HCl immobilization effect via forming hydrogen bonds between HCl and the keto oxygen, carboxyl keto oxygen in CQDs. The hydroxyl group in CQDs could also combine ZnCl2 by forming a coordination bond. [ABSTRACT FROM AUTHOR]

BACKGROUND: Photostability is an important property in agrochemicals, impacting their biological efficacy, environmental fate and registrability. As such, it is a property that is routinely measured during the development of new active ingredients and their formulations. To make these measurements, compounds are typically exposed to simulated sunlight after application to a glass substrate. While useful, these measurements neglect key factors that influence photostability under true field conditions. Most importantly, they neglect the fact that compounds are applied to living plant tissue, and that uptake and movement within this tissue provides a mechanism to protect compounds from photodegradation. RESULTS: In this work, we introduce a new photostability assay incorporating leaf tissue as a substrate, designed to run at medium throughput under standardized laboratory conditions. Using three test cases, we demonstrate that our leaf‐disc‐based assays provides quantitatively different photochemical loss profiles to an assay employing a glass substrate. And we also demonstrate that these different loss profiles are intimately linked to the physical properties of the compounds, the effect that those properties have on foliar uptake and, thereby, the availability of the active ingredient on the leaf surface. CONCLUSIONS: The method presented provides a quick and simple measure of the interplay between abiotic loss processes and foliar uptake, supplying additional information to facilitate the interpretation of biological efficacy data. The comparison of loss between glass slides and leaves also provides a better understanding of when intrinsic photodegradation is likely to be a good model for a compound's behaviour under field conditions. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The purpose of this study was the preparation of layered double hydroxide (LDH) ‐based nanohybrids with improved photoluminescence emission and high photostability. The anion exchange‐based microwave method was applied for the intercalation of mordant orange 1 into MgAl‐LDH. The prepared organic‐inorganic nanohybrid was confirmed by X‐ray diffraction, thermal gravimetric analysis (TGA), inductively coupled plasma spectrometry (ICP), and infrared spectra (FT‐IR). Also, the morphology of the obtained sample was investigated using the field emission‐scanning electron microscopy (FE‐SEM) method. In the MgAl‐LDH interlayer space, a tilted orientation and bilayer arrangement were predicted for the mordant orange 1 anions. Compared with the pure mordant orange 1, the MgAl‐LDH/mordant orange 1‐MA (prepared using the microwave‐based anion exchange method) has improved photoluminescence emission with high Photostability. These findings supply a new approach for designing photoluminescence materials that potentially apply to optical devices with high Photostability. [ABSTRACT FROM AUTHOR]

Raman‐fluorescence dual‐mode enhanced nanoparticles have enormous potential for bioimaging with combined advantages of sensitivity and speed. This is primarily achieved through a trade‐off between fluorescence quenching and electromagnetic (EM) enhancement on the plasmonic metal surface, as demonstrated in previous research. A strategy that can minimize EM‐field attenuation and temporal photobleaching would be highly desirable. In this study, a novel approach using Raman‐fluorescence enhanced dual‐mode nanoparticles with the near‐infrared fluorescence reporter IR780 directly embedded in the ultra‐high EM fields between gold (Au) nanopetals of various morphology and a silver (Ag) coating without a spacer is presented. The results show these nanoparticles to be single‐nanoparticle Raman sensitive and that they can generate a fluorescence enhancement factor as high as 1113 experimentally and 2000 by numerical simulation. The random morphology of the nanopetals supports broadband resonances for both fluorescence excitation and emission, resulting in nanowatt detectability, the dual‐mode photostability of more than 30 min under continuous laser irradiation, and a long shelf life, making them promising for wide applications in bioimaging with ultra‐brightness, low laser power, and long‐duration monitoring. In summary, they represent a novel strategy for high‐performance Raman‐fluorescence enhancement dual‐mode nanotags. [ABSTRACT FROM AUTHOR]

Indocyanine green (ICG) is the only near‐infrared (NIR) dye approved for clinical use. Despite its versatility in photonic applications and potential for photothermal therapy, its photobleaching hinders its application. Here we discovered a nanostructure of dimeric ICG (Nano‐dICG) generated by using ICG to stabilize nanoemulsions, after which ICG enabled complete dimerization on the nanoemulsion shell, followed by J‐aggregation of ICG‐dimer, resulting in a narrow, red‐shifted (780 nm→894 nm) and intense (≈2‐fold) absorbance. Compared to ICG, Nano‐dICG demonstrated superior photothermal conversion (2‐fold higher), significantly reduced photodegradation (−9.6 % vs. −46.3 %), and undiminished photothermal effect (7 vs. 2 cycles) under repeated irradiations, in addition to excellent colloidal and structural stabilities. Following intravenous injection, Nano‐dICG enabled real‐time tracking of its delivery to mouse tumors within 24 h by photoacoustic imaging at NIR wavelength (890 nm) distinct from the endogenous signal to guide effective photothermal therapy. The unprecedented finding of nanostructure‐driven ICG dimerization leads to an ultra‐stable phototheranostic platform. [ABSTRACT FROM AUTHOR]

X‐ray imaging technology has been widely used in the fields of environmental monitoring, safety inspection, nondestructive examination, space exploration, and medical diagnosis, among which scintillation materials play a vital role in indirectly converting X‐ray to visible photons. Here, a zero‐dimensional organic–inorganic hybrid halide C50H44P2SbCl5 crystal is prepared via a facile antisolvent precipitation method at room temperature. The single crystal of C50H44P2SbCl5 displays a strong yellow broadband emission centered at 592 nm with a near‐unity photoluminescence quantum yield of 98.42%. Importantly, C50H44P2SbCl5 crystals show great environmental stability and irradiation stability. Radioluminescence characterization indicates that C50H44P2SbCl5 crystals exhibit a good linear response to X‐ray dose rates along with an excellent light yield of 44 460 photons MeV−1, surpassing that of commercial inorganic LuAG:Ce scintillator. The spatial resolution of the C50H44P2SbCl5‐based scintillating screen is determined to be 8.2 lp mm−1. In conjunction with polymer thin film, the excellent scintillating feature of organic–inorganic hybrid halides offers exciting opportunities for achieving high‐quality flexible X‐ray imaging. [ABSTRACT FROM AUTHOR]

A series of NIR absorbing and emitting, naphthobipyrrole derived BODIPY dyes are reported. These dyes possess different functional groups viz. −CHO, −CN, −NO2, ‐Br and Ph at its α,α′‐positions. All the derivatives were characterized thoroughly via various spectroscopic means as well as single‐crystal X‐ray structural analyses. Impacts of functionalization on its photophysical properties as well as photostability were evaluated. For instance, incorporation of the phenyl moieties at the α, α′‐positions by Suzuki coupling of the dibromo‐derivative 4 with phenyl boronic acid led to substantial bathochromic shift in absorption (762 vs 727 nm) and emission (778 vs 744 nm) relative to the unsubstituted parent dye VI. Theoretical calculations have been performed by ground state optimization to evaluate the electronic transitions which supports experimental observation. [ABSTRACT FROM AUTHOR]

The severe photocorrosion of BiVO4 limits its application in solar energy conversion in the long‐term photoelectrochemical stability test. Herein, we synthesized a Fe@Ni‐MOFs/BiVO4 photoanode by a simple ultrasonic method and ultrafast deposition, which avoids the problems of damaging the surface structure of photoelectrode. The Fe@Ni‐MOFs/BiVO4 shows a photocurrent density of 4.89 mA cm−2 at 1.23 VRHE with an onset potential of 0.25 VRHE under one sun illumination. Importantly, a stability over 30 h at 0.7 VRHE can be obtained, which is so far the best stability character for MOFs‐based cocatalysts decorated on BiVO4. During operation, Fe@Ni‐MOFs transforms into a homogeneous and active hydroxide layer covering the surface, which exposes more active sites for OER reactions. This work demonstrates a simple strategy for MOFs co‐catalysts to obtain fast hole transfer capability and reduce carrier recombination, thereby improving PEC performance. [ABSTRACT FROM AUTHOR]

Herein, a new ternary strategy to fabricate efficient and photostable inverted organic photovoltaics (OPVs) is introduced by combining a bulk heterojunction (BHJ) blend and a fullerene self‐assembled monolayer (C60‐SAM). Time‐of‐flight secondary‐ion mass spectrometry ‐ analysis reveals that the ternary blend is vertically phase separated with the C60‐SAM at the bottom and the BHJ on top. The average power conversion efficiency ‐ of OPVs based on the ternary system is improved from 14.9% to 15.6% by C60‐SAM addition, mostly due to increased current density (Jsc) and fill factor ‐. It is found that the C60‐SAM encourages the BHJ to make more face‐on molecular orientation because grazing incidence wide‐angle X‐ray scattering ‐ data show an increased face‐on/edge‐on orientation ratio in the ternary blend. Light‐intensity dependent Jsc data and charge carrier lifetime analysis indicate suppressed bimolecular recombination and a longer charge carrier lifetime in the ternary system, resulting in the enhancement of OPV performance. Moreover, it is demonstrated that device photostability in the ternary blend is enhanced due to the vertically self‐assembled C60‐SAM that successfully passivates the ZnO surface and protects BHJ layer from the UV‐induced photocatalytic reactions of the ZnO. These results suggest a new perspective to improve both performance and photostability of OPVs using a facial ternary method. [ABSTRACT FROM AUTHOR]

Supramolecular self‐assembly is a promising strategy for stabilizing the photo‐sensitive components in photocatalysis. However, the underlying correlation between the enhanced photostability and supramolecular structure at the molecular level has not yet been fully understood. Herein, we develop a biomimetic vesicular membrane‐based polyporphyrin photocatalyst exhibiting excellent photocatalytic stability with at least activity time of 240 h in hydrogen generation. Time‐domain ab initio modelling together with transient absorption spectroscopy, visual frontier orbitals and Gibbs free energy calculation disclose that the ordered aggregation of porphyrin units in the vesicle membrane facilitates "hot" electron relaxation and the rapid dissipation of photo‐generated charges, thereby contributing to the longevity. This work deepens the molecular‐level understanding on photostability and photocatalytic mechanism of supramolecular photocatalysts. [ABSTRACT FROM AUTHOR]

Developing halogen‐functionalized fluorescent dyes with intriguing photophysical properties, including enhanced photostability, is particularly important for bioimaging. In this work, we synthesized two new halogen‐functionalized aggregation‐induced emission (AIE)‐active molecules, DQMF‐OH and DQMCl‐OH, based on the quinoline‐malononitrile chromophore. The halogen effect on the photophysical characteristics was detailedly studied by absorption and fluorescence spectroscopy, density functional theory calculations, and crystal structures. Compared with non‐halogen substituted AIE luminogen (AIEgen) DQM‐OH, the halogen substituted DQMF‐OH and DQMCl‐OH exhibited red‐shifted absorptions and emissions in the solution and solid state. In addition, DQMF‐OH and DQMCl‐OH also possessed enhanced fluorescence toward viscosity changes. These AIEgens served as remarkable imaging tools for cell tracking in a wash‐free manner. Furthermore, DQMF‐OH and DQMCl‐OH showed much more excellent photobleaching resistance than DQM‐OH. Our work sheds new light on developing fluorescent halogenated dyes with enhanced photophysical performances for biological applications. [ABSTRACT FROM AUTHOR]

Photostability of colloidal quantum dots (QDs) is one of the major criteria determining their long‐term applicability in energy and chemical technologies. Yet, photostability studies of QDs are extremely sensitive to experimental conditions, lack a detailed mechanistic understanding, and are time‐, material‐, and labor‐intensive. Herein, an automated microfluidic platform for accelerated photostability studies of colloidal QDs is introduced, 3.5× faster and 100× more material efficient than the conventional flask‐based studies. The developed microfluidic strategy provides real‐time in situ access to the optical properties of QDs throughout the photostability experiments. Specifically, the material‐efficient microfluidic platform is used to study the mechanism and kinetics of CdSe QDs' photodegradation. The studies suggest that a generation of singlet oxygen via triplet energy transfer from colloidal CdSe QDs can initiate photo‐oxidation of CdSe QDs. Furthermore, the presence of at least one additional photodegradation pathway of CdSe QDs parallel to the photo‐oxidation pathway is unveiled. The systematic photostability experiments reveal how the incident photon flux and the starting average diameters of CdSe QDs affect their photodegradation rates. This work sheds light on the complex and multifaceted photodegradation phenomena of colloidal CdSe QDs and illustrates the unique characteristics of microfluidic strategies to improve and accelerate photostability studies of QDs. [ABSTRACT FROM AUTHOR]