Nickel complexes with porphyrin-type ligands are the second most abundant in crude oil after vanadium complexes; in certain fossils, their relative concentration may be even higher. In this work, nickel(II) etioporphyrin-III, Ni-EtioP-III, a member of the etio-type family of oil porphyrins, was synthesized and investigated with a particular interest in its solid-state properties. A single-crystal X-ray analysis determined the molecular and crystal structure of Ni-EtioP-III. The electronic absorption spectra, morphology and photoelectrical parameters of vacuum-sublimed Ni-EtioP-III films were compared to those of kindred etioporphyrins compounds having a different positional isomery and central metal ions. Variations in the microscopic film morphology and crystal arrangement are poorly reflected in the absorption spectra. Archetypal thin-film photovoltaic cells with a planar donor/acceptor heterojunction where the Ni-EtioP-III donor is paired with the Cl 6 SubPc acceptor show a moderate photovoltage of 0.58 V and a short-circuit current density of 1.8 mA/cm 2 . This results in a low efficiency of no more than 1%, which is typical for planar metallo-etioporphyrins. The best photovoltaic performance with a 2.3% efficiency was measured in the cells with a non-planar vanadyl complex, VO-EtioP-III as the donor, along with a very high photosensitivity and rectification ratio of 8⋅10 5 .

Relative abundance of vanadyl etio-porphyrin-III, VO-EtioP-III, a typical geoporphyrin, reaches its maximum in solid fossil fuels (coals). This determines the interest in studying supramolecular structure and solid-state properties of this compound. Unlike planar etio-type porphyrins, the visible absorption spectra of VO-EtioP-III undergo significant transformation in transition from a solution to solid films, which is associated with formation of supramolecular aggregates. In this work, we compare the spectra of VO-EtioP-III films deposited by thermal evaporation of powder in vacuum (VTE) or by spin-coating of dissolved compound (SC) to prove that they are similar to those observed for binary solutions in which adding water to methanol also initiates aggregation. The absorption spectra of VTE-films are very sensitive to the film thickness and deposition conditions. The spectral studies are supplemented with analysis of the microscopic morphology and conducting properties of the films. While the photoconductivity of solution-processed VO-EtioP-III films suffers due to the inhomogeneity of their structure, the VTE-films behave as good photoconductors with a lateral current response to sunlight up to 105.

Absorption spectra and the structure of films of the organic pigment vanadyl phthalocyanine (PcVO) with a thickness less than 100 nm are studied before and after prolonged exposure to sunlight or LED sources in the near-UV, visible, and near-IR regions (368 nm, 535 nm and 866 nm, respectively). While the phase structure of the films is insensitive to sunlight, the spectral profiles are characteristically changed by narrow-band illumination whose integral intensity is one order of magnitude smaller but is applied in the regions close to the main optical maxima (Q-band and Soret band). The observed changes indicate a partial polymorphic transition in the layer. Direct structural methods (XRD, scanning electron microscopy, optical interference microscopy) are much less informative in the case of films with such thicknesses, which are most often used in organic optoelectronics devices.

В работе исследовались спектры поглощения и структура пленок органического пигмента фталоцианина ванадила (PcVO) толщиной менее 100 нм до и после длительного воздействия солнечного света или LED-источников в ближней УФ-, видимой и ближней ИК-области (368, 535 и 866 нм, соответственно). Хотя фазовая структура пленок оказалась нечувствительна к солнечному свету, узкополосное освещение на порядок меньшей интегральной мощности, но в областях близких к основным оптическим максимумам (Q-полоса и полоса Сорэ), характерным образом меняет профили спектров. По наблюдаемым изменениям можно судить о частичном полиморфном переходе в слое. При этом, прямые структурные методы (рентгеновская дифракция, сканирующая электронная и оптическая интерференционная микроскопия) оказываются гораздо менее информативными для пленок данных толщин, которые наиболее часто используются в устройствах органической оптоэлектроники.

A new complex of indium(III)chloride with etioporphyrin-I was synthesized and characterized. As with naturally occurring extraligated etioporphyrins, the InCl-EtioP-I spectrum in solution has a very strong B-band and a more than an order of magnitude weaker Q-band, but this difference diminishes in solid films of InCl-EtioP-I obtained by thermal evaporation in vacuum. In a solid, molecules have a tight convex-convex arrangement in a 2D double layered structure with interplane distance of 3.066 Å. The conductivity of films can easily be activated by the action of temperature or light. In the cells with symmetrical lateral contacts the photocurrent exceeds the dark current by about three orders of magnitude, with the contribution of photons in the Q-band range being greater than expected from the experimental or calculated absorption spectrum. The Q-bands contribute significantly to the photovoltaic effect in the ITO/InCl-EtioP-I/Al sandwich cells. Such cells show an untypically strong signal in the photodiode regime, which yields the spectral detectivity of 10^12 Jones.

In this review, we generalize the research results obtained by Russian scientists in the last 10-15 years for porphyrins, related compounds, and their metal complexes with a pronounced application potential. The main attention is paid to the analysis of relationships between the spectral, catalytic, and sensor properties of tetrapyrrole compounds and the structure of peripheral substituents and axial ligands and the nature of the coordinating metal atom.

Stable subphthalocyanine-type dyes with a high electron affinity attract much attention as potential substitutes for traditional fullerenes in molecular electronics devices. One possible way to enhance the acceptor properties of the subphthalocyanine core is by replacing the peripheral benzene fragments (C6H4) with 1,2,5-thiadiazole fragments (C2N2S1). However, the resistance of these materials to light or atmospheric effect remains an open question, which limits their further application in device manufacturing. In this work, we compare vacuum-deposited films of three derivatives, SubPzS(3)H(0) (all peripheral fragments are 1,2,5-thiadiazoles), SubPzS(2)H(4) (two fragments are 1,2,5-thiadiazoles and one fragment is benzene), and SubPcS(0)H(12) (all benzenes, i.e., parent subphthalocyanine). Practically relevant substrates were used for deposition, namely, bare glass, glass/ITO or FTO, and PET/ITO. Photobleaching of films under continuous 1 sun illumination was studied in laboratory air, synthetic air, and ultrapure argon. It is shown that the exclusion of near-UV photons from the incident light spectrum, which corresponds to the absorption of subphthalocyanines in the Soret-band, strongly inhibits degradation. Absorption in the Q-band range initiates soft annealing rather than photobleaching of films. The stability of the films deposited on glass decreases as SubPzS(3)H(0) > SubPzS(2)H(4) > SubPcS(0)H(12) in air, and vice versa in argon. The substrate adds more complexity to this picture. In argon, the ITO coating reduces degradation of all of the compounds equally, in contrast to the glass samples, while in air, the SubPzS(3)H(0) films discolor completely. The latter reaction proceeds due to the indium-containing species migrating from the conductive coating.

Manganese (II) phthalocyanine MnPc is known for its interesting magnetic prop-erties and diverse coordination chemistry, but little is known about its conductivity. In our previous work, we observed how introduction of a permanent magnetic field during deposition modifies the microcrystalline structure of the growing MnPc films. In this paper, we have shown that the magnetic field, together with the substrate temperature, is responsible for the lateral current in the two-terminal MnPc-based cells with interdigital contacts to change, while the influence of atmospheric environment and illumination is much less noticeable.

В данном обзоре обобщены результаты исследований в области порфиринов, родственных соединений и их металлокомплексов с явно выраженным прикладным потенциалом, выполненных российскими учеными в последние 10-15 лет. Основное внимание сосредоточено на анализе взаимосвязи спектральных, каталитических и сенсорных свойств тетрапиррольных соединений со строением экваториального порфиринового и аксиальных лигандов и природой координирующего атома металла.

Complexes of etioporphyrin with transition metal ions are abundant in fossil fuels (hence the term petroporphyrins); their isolation from crude material or by laboratory synthesis are well-known procedures. Nonetheless, there are few examples of practical applications of these available and stable materials. We report an attempt to systematically introduce five synthetic etioporhyrin (EtioP) complexes with copper and nickel into archetypal thin-film photovoltaic cells fabricated entirely by vacuum thermal evaporation. It is shown that EtioPs act as effective donors in a planar heterojunction, where another porphyrinoid molecule, hexachloro-subphthalocyanine boron chloride Cl6SubPc, is used as an acceptor. The efficiency of the devices is limited due to the narrow-band absorption by the D/A pair and, hence, insufficient photon capturing from the sunlight spectrum. No clear correlation of the device parameters with the position isomerism or frontier molecular orbital energies of EtioPs is found. Best photovoltaic performance is shown by the Cu-EtioP-II based devices.

We report a study on two types of the model thin-film systems: a bilayer SubPc/C60 film and variously mixed (co-deposited) SubPc:C60 films, where SubPc is boron chloride subphthalocyanine, C60 is buckminsterfullerene, both materials are small molecule semiconductors widely known in photovoltaics. These systems were subjected to a full-day exposure (13 h) to a simulated sunlight in air, which was expected to cause either photodestruction or soft annealing of molecular materials, or both. The morphology of the films in the aged and pristine states was assessed and compared using four methods: ToF-SIMS, optical spectroscopy, surface relief analysis and XRD. Based on the findings, the following conclusions can be made: 1) Neither interlayer mixing in the bilayer nor any noticeable phase delamination occur in the mixed systems; 2) Ageing affects the film morphology rather than depth distribution of its components; 3) SubPc component gets strongly oxidized/destroyed with ageing; 4) In a gradient mixed film the concentration of the components tends to equalize through the ageing process; 5) Fullerene may demonstrate some features of ordering, whereas SubPc remains X-ray amorphous.

As a follow-up to our study on aggregation of metal-etioporphyrin complexes (Colloids Surf. A. Physicochem. Eng. Asp. 2022, 648, 129284), we considered thin films of three isomers of copper(II) etioporphyrin deposited on hot substrates. Despite the almost identical absorption spectra of isomers, their solid-state superstructures differ remarkably both in form and size. The lateral conductivity of films is much less sensitive to an isomer-type, regardless of the substrate temperature. However, the dark conductivity of cold-grown films is about two orders of magnitude higher than that of hot-grown films, whereas the photoconductivity of the latter is 100–1700 times greater, depending on the isomer.

The heat transfer in an archetypal system solar cell/environment was analyzed, in which the solar cell was a thin-film multilayer structure with a hybrid lead-iodide perovskite photoabsorber. The temperature field was mathematically modeled and heat maps of the cell at various irradiation intensities were calculated. It was found that the heating by a diffuse insolation does not exceed the threshold critical for the stability of the perovskite phase owing to dissipation into the environment, with the temperature maximum close to half of the overall thickness of the structure. Keywords: perovskite, thin film, heat transfer, solar cells, diffuse insolation.

In this paper, we investigate the applicability of a vacuum-deposited layer of porphyrazine [series] pigment, the tris(1,2,5-thiadiazolo)subporphyrazinatoboron(III) chloride (SubPzS3), as optical filter for inverted perovskite solar cells. Thin films formed from this material are characterized by a narrow, high-intensity absorption band in the visible range, with a maximum at ~ 545 nm. The operation stability of the device was assessed by the dynamic J–V characteristics. The efficiency of solar cells equipped with such optical filter is lower due to a decrease in the total number of photons absorbed by the perovskite layer. However, their stability to photolysis by the impact of sunlight is higher and, what is more, the filtered radiation has a stabilizing effect on the performance of cells under long-term illumination. Transformation of the perovskite material in the solar cells is determined by a trade-off between destructive and healing photons that penetrate into the perovskite photoabsorber depending on whether or not it has a filtering layer.

The heat transfer in an archetypal system ‘solar cell/environment’ was analyzed, in which the solar cell was a thin-film multilayer structure with a hybrid lead-iodide perovskite photoabsorber. The temperature field was mathematically modeled and heat maps of the cell at various irradiation intensities were calculated. It was found that the heating of the structure by a diffuse insolation has a maximum at about half of the overall thickness, but it does not exceed the threshold critical for the stability of the perovskite phase owing to dissipation into the environment.

Manganese phthalocyanine, Mn(II)Pc, is a disc-like paramagnetic molecule whose unusual electronic structure have been studied for decades. However, no credible results on the direct impact of intrinsic molecular magnetism on the solid state properties of Mn(II)Pc are known. In this work, the Mn(II)Pc films were deposited by thermal vacuum evaporation with and without applying an external static magnetic field with a strength of a few tenths of a Tesla to the growth zone. Evolution of the microstructure of the thus formed films was documented using XRD, SEM, AFM and optical methods. In the field-free conditions, the Mn(II)Pc films deposited on the hot substrate are rather smooth, continuous and strongly textured. Large needle-like crystals (whiskers) grow when magnetic field is turned on, without noticeable correlation with the direction of field lines. However, the density of whiskers per unit area increases with increasing field strength. Possible explanations of the growth mechanism include molecular surface diffusion, adsorption energy lowering and Lorentz force but none of them is yet internally consistent.

Self-assembly and electrical properties of chlorophyll-type dyes are reviewed with emphasis on their potential applications in thin-film solar cells.

The template synthesis of novel bis-tetrabenzoporphyrin complexes of gadolinium, erbium and lutetium is described. The structure of these sandwich-type complexes was confirmed by the elemental analysis, MALDI-TOF mass spectrometry and optical spectroscopy in the visible, near and middle infrared range. The electrochemical behavior was studied by the cyclic voltammetry and compared to that of the structurally similar bis-phthalocyanine lanthanides. The conductivity of thin films of bis-tetrabenzoporphyrin complexes was measured both in the dark and under illumination. Thin films of erbium complex showed the highest photosensitivity, while the films of the gadolinium complex have the lowest resistivity.

The thin film properties of the new hexachloro-pyrazinosubporphyrazine compound, Cl6-pSubPz, were studied in comparison with those of an effective molecular acceptor, hexachloro-substituted subphthalocyanine, Cl6-SubPc. The latter compound is widely used in organic photovoltaics as electron acceptor (n-type layer). It was shown that with high-vacuum sublimation Cl6-pSubPz forms stable, smooth and highly textured films on many functional inorganic surfaces. The position of the main electronic absorption band (Q-band) of this compound in the visible range coincides with the maximum of the solar spectrum. Specific conductivity of the sublimed films of both studied compounds lies in the same range, but its thermal activation energy for Cl6-pSubPz is two times higher than for Cl6-SubPc.

The J-V characteristics of perovskite-based solar cells were measured under selective irradiation in three different domains of the solar spectrum: blue, red and near infrared (NIR). It was found out that even in the inert atmosphere a long-term exposure to both blue and red sources leads to formation of PbI2, but in the former case the degradation of hybrid perovskite is greater due to further photolysis of PbI2. Consequently, the cell performance under illumination with the red light decreases insignificantly. The NIR irradiance improves the perovskite stoichiometry so that the photovoltaic parameters of the cells increase with the exposure time. These features are undistinguishable under continuous sunlight. Therefore, the wavelength-selective J-V measurements piece together the jigsaw of light-induced degradation of hybrid perovskites and open new strategies for the improvement of the device stability.