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Diammonium Porphyrin-induced CsPbBr3 Nanocrystals to Stabilize Perovskite Film for Efficient and Stable Solar Cells
摘要： Employing all-inorganic perovskite quantum dots (QDs) to treat the organic-inorganic perovskite film has well-documented as a serviceable tactics to improve the performance of perovskite solar cells (PSCs). Whereas the inert molecules-coated QDs with zero dimension (0D) structure would limit further enhancement of the efficiency and stability of PSCs. Here we employ a conductive diammonium porphyrin (ZnPy-NH3Br) to treat CsPbBr3 QDs coated on 3D perovskite film, thus constructing a stable 0D-2D perovskite capping layer. The generation of large-scale nanocube crystals by treating CsPbBr3 nanocrystallites with ZnPy-NH3Br in solution demonstrates such an assembly strategy. The formed capping layer can achieve efficient charge transport and separation. As a consequence, the best efficiency of optimized device is up to 20.0%, which is superior to the control PSCs fabricated without modification (19.1%) and with pure CsPbBr3 QDs modification (19.5%). More importantly, the porphyrin-treated CsPbBr3 QDs based devices retain over 65% or 85% of their initial efficiency when placed at 85 °C or 45% humidity tracking for 1000 h, respectively. And also, with the QDs-Por incorporated, the device retained 85% of the original efficiency when illuminated at the AM 1.5 G for 450 h. Therefore, this work offered a facile avenue to modify perovskite film for fabricating the highly efficient and stable PSCs.
关键词： Perovskite solar cells,CsPbBr3 quantum dots,Protective layer,Ligand exchange,Porphyrins
更新于2025-09-23 15:19:57
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Performance of Localized Coupled Cluster Methods in a Moderately Strong Correlation Regime: H??ckel-M??bius Interconversions in Expanded Porphyrins
摘要： Localized orbital coupled cluster theory has recently emerged as a nonempirical alternative to DFT for large systems. Intuitively, one might expect such methods to perform less well for highly delocalized systems. In the present work, we apply both canonical CCSD(T) and a variety of localized approximations thereto to a set of flexible expanded porphyrins — macrocycles that can switch between Hückel, figure-eight, and M?bius topologies under external stimuli. Both minima and isomerization transition states are considered. We find that M?bius(-like) structures have much stronger static correlation character than the remaining structures, and this causes significant errors in DLPNO-CCSD(T) and even DLPNO-CCSD(T1) approaches, unless TightPNO cutoffs are employed. If sub-kcal mol-1 accuracy with respect to canonical relative energies is required even for M?bius-type systems (or other systems plagued by strong static correlation), then Nagy and Kallay’s LNO-CCSD(T) method with “tight” settings is the suitable localized approach. We propose the present POLYPYR21 dataset as a benchmark for localized orbital methods, or more broadly, for the ability of lower-level methods to handle energetics with strongly varying degrees of static correlation.
关键词： topology interconversions,nondynamical correlation,expanded porphyrins,localized coupled cluster,canonical coupled cluster
更新于2025-09-23 15:19:57
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Synthesis and electronic properties of A <sub/>3</sub> B-thienyl porphyrins: experimental and computational investigations
摘要： A convenient reaction protocol has been explored for the synthesis of A3B-type meso substituted porphyrins containing three thien-2-yl groups and one substituted phenyl group. 100–150 mg of pure A3B thienyl porphyrins was obtained from a single reaction in the case of 4-hydroxyphenyl, 3-nitrophenyl, 3,4,5-trimethoxyphenyl, 3,4-dimethoxyphenyl and 4-pyridyl substituents. NMR, UV-vis, fluorescence and electrochemical studies were conducted using pure products to understand the effect of the nature of the meso phenyl group on the electronic properties. X-ray structural analysis of thienyl porphyrins containing 4-hydroxyphenyl and 3,4,5-trimethoxyphenyl residues confirmed the substituent regiochemistry and the conformations of the thienyl groups in the solid state. The UV-vis and fluorescence bands experienced modest blue shifts when compared to meso-tetrathien-2-yl porphyrin (H2T-2-TP). The redox potentials showed cathodic shifts with respect to H2T-2-TP and revealed variation of frontier orbital energy levels depending upon the phenyl substituent. Computational DFT and TD-DFT studies on all the phenyl derivatives confirmed the role of the phenyl substituent in modulating the HOMO and LUMO energy levels and agree well with the observed effects of the optical bands and the redox potentials.
关键词： TD-DFT,DFT,A3B-thienyl porphyrins,electronic properties,synthesis
更新于2025-09-19 17:15:36
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Photoredox Arylation of Enol Acetates via Porphyrin Catalysis
摘要： Photoredox Arylation of Enol Acetates via Porphyrin Catalysis
关键词： diazonium salts,porphyrins,photoredox arylation
更新于2025-09-19 17:15:36
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The in vitro Photoinactivation of Helicobacter pylori by a Novel LED-Based Device
摘要： The rise of antibiotic resistance is the main cause for the failure of conventional antibiotic therapy of Helicobacter pylori infection, which is often associated with severe gastric diseases, including gastric cancer. In the last years, alternative non-pharmacological approaches have been considered in the treatment of H. pylori infection. Among these, antimicrobial PhotoDynamic Therapy (aPDT), a light-based treatment able to photoinactivate a wide range of bacteria, viruses, fungal and protozoan parasites, could represent a promising therapeutic strategy. In the case of H. pylori, aPDT can exploit photoactive endogenous porphyrins, such as protoporphyrin IX and coproporphyrin I and III, to induce photokilling, without any other exogenous photosensitizers. With the aim of developing an ingestible LED-based robotic pill for minimally invasive intragastric treatment of H. pylori infection, it is crucial to determine the best illumination parameters to activate the endogenous photosensitizers. In this study the photokilling effect on H. pylori has been evaluated by using a novel LED-based device, designed for testing the appropriate LEDs for the pill and suitable to perform in vitro irradiation experiments. Exposure to visible light induced bacterial photokilling most effectively at 405 nm and 460 nm. Sub-lethal light dose at 405 nm caused morphological changes on bacterial surface indicating the cell wall as one of the main targets of photodamage. For the first time endogenous photosensitizing molecules other than porphyrins, such as flavins, have been suggested to be involved in the 460 nm H. pylori photoinactivation.
关键词： flavins,porphyrins,LEDs,antimicrobial PDT,Helicobacter pylori
更新于2025-09-19 17:13:59
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Design of New n-Type Porphyrin Acceptors with Subtle Side-Chain Engineering for Efficient Nonfullerene Solar Cells with Low Energy Loss and Optoelectronic Response Covering the Near-Infrared Region
摘要： A series of tailor-made highly efficient and near-infrared porphyrin-based acceptors is designed and synthesized for fullerene-free bulk-heterojunction (BHJ) organic solar cells (OSCs). Constructing BHJ active layers using a PTB7-Th donor and porphyrin acceptors (P-x), which have complementary absorption, accomplish panchromatic photon-to-current conversion from 300 to 950 nm. Our study shows that side-chains of the porphyrin acceptors fairly influences the molecular ordering and nanomorphology of the BHJ active layers. Significantly, porphyrin acceptor with four dodecoxyl side-chains (P-2) achieves an open-circuit voltage (VOC) of 0.80 V, a short-circuit current density (JSC) of 13.94 mA cm-2, a fill factor (FF) of 64.8%, and overall power conversion efficiency (PCE) of 7.23%. This great performance is attributable to the ascendant light-harvesting capability in the visible and NIR region, a high-lying LUMO energy level, a relatively high and more balanced carrier mobilities, and more ordered face-on molecular packing, which is beneficial for obtaining high VOC and JSC.
关键词： near-infrared absorption,porphyrins,organic solar cells,nonfullerene acceptors,n-type porphyrins
更新于2025-09-12 10:27:22
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A new type of multibenzyloxy-wrapped porphyrin sensitizers for developing efficient dye-sensitized solar cells
摘要： Porphyrin dyes have been widely used for the fabrication of efficient dye-sensitized solar cells (DSSCs). However, dye aggregation and charge recombination still exert negative effects on photovoltaic performance, resulting in unsatisfactory power conversion efficiencies (PCE). Herein, we report a new class of porphyrin sensitizers XW52 and XW53 employing four benzyloxy groups to wrap the porphyrin cores. As a result, an efficiency of 7.6% was obtained for XW52, with Voc and Jsc of 668 mV and 16.63 mA cm-2, respectively. Compared with XW52, an additional 2,6-dialkoxyphenyl group has been introduced to the N-atom of the phenothiazine donor to furnish XW53 with the aim to further improve the anti-aggregation character and the solubility, and thus the Voc was improved to 674 mV, and a higher efficiency of 7.9% was achieved for XW53. Upon cosensitization with PT-C6, the Voc and Jsc were synergistically enhanced to 727 mV and 18.67 mA cm-2, respectively. As a result, a high efficiency of 9.6% was successfully achieved for the cosensitization system of XW53 + PT-C6. These results provide an effective novel strategy for designing efficient porphyrin dyes by introducing multiple benzyloxy groups to the meso-phenyl groups.
关键词： cosensitization,porphyrins,dye aggregation,dye-sensitized solar cells,wrapped structures
更新于2025-09-12 10:27:22
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Tuning of structural and optical properties of 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphine thin films as a promising photovoltaic absorber material
摘要： Thin films of 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphine (H2TPyP) dye have been prepared using thermal evaporation technique. The crystal structure has been studied using the field emission scanning electron microscopy and X-ray diffraction pattern. The structure investigation of H2TPyP exhibited a polycrystalline nature in the form of powder while the thin films revealed a nanocrystalline structure. The optical features of H2TPyP thin films have been examined using spectroscopic measurements of the absorbance, the transmittance, and the reflectance of those films within spectral range of 200–2500 nm. From such measurements, the optical constants, the dispersion parameters, and the related optical variables were calculated and interpreted. The absorbance spectra of the films revealed the four quasi-electronic states named Q-bands and more intense Soret (B) band located at UV–visible spectral region. In addition to other weaker bands labeled M, N, and L observed at UV spectrum. The electronic inter-band transition for the H2TPyP thin films revealed an indirect allowed transition with the onset optical band gap Eg of 1.78 eV. Urbach tail energy EU was observed beyond the Eg and was found to be 0.36 eV. Furthermore, the energy loss functions, dielectric constants and optical conductivities were also studied.
关键词： Thin films,Structure analysis,Optical properties,Energy loss functions,Porphyrins
更新于2025-09-11 14:15:04
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Triplet‐Triplet Annihilation Upconversion in a MOF with Acceptor‐filled Channels
摘要： Photon upconversion enjoys an increasing interest in the last years due to its high potential for solar energy harvesting and in bio-imaging. A challenge for triplet-triplet annihilation upconversion (TTA-UC) processes is to realize these features in solid materials without undesired phase segregation and detrimental dye aggregation. To achieve this, we combine a palladium porphyrin sensitizer and a 9,10-diphenylanthracene annihilator within a crystalline mesoporous metal-organic framework using an inverted design. In this modular TTA system, the framework walls constitute the fixed sensitizer, while caprylic acid coats the channels providing a solvent-like environment for the mobile annihilator in the channel. The resulting solid material shows green-to-blue delayed upconverted emission with a luminescence lifetime of 373±5 μs, a threshold value of 329 mW cm–2 and a triplet-triplet energy transfer efficiency of 82%. The versatile design allows straightforward changing the acceptor amount and type.
关键词： triplet-triplet annihilation,porphyrins,metal-organic frameworks,upconversion,hybrid materials
更新于2025-09-11 14:15:04
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Exploration of Interfacial Porphine Coupling Schemes and Hybrid Systems by Bond-Resolved Scanning Probe Microscopy
摘要： The templated synthesis of porphyrin-based oligomers and heterosystems is of considerable interest for materials with tunable electronic gaps, photovoltaics, or sensing device elements. In this work, temperature-induced dehydrogenative coupling between unsubstituted free-base porphine units and their attachment to graphene nanoribbons on a well-defined Ag(111) support are scrutinized by bond-resolved scanning probe microscopy techniques. The detailed inspection of covalently fused porphine dimers obtained by in vacuo on-surface synthesis clearly reveals atomistic details of coupling motifs, whereby also putative reaction intermediates are identified. Moreover, the covalent attachment of porphines at preferred locations of atomically precise armchair-type graphene nanoribbons is demonstrated.
关键词： porphyrins,graphene nanoribbons,scanning probe microscopy,surface chemistry,C–C coupling
更新于2025-09-10 09:29:36