Subsequent Thermal Annealing Research Articles

Printing High‐Quality Formanidinum Lead Triiodide Films: Understanding the Critical Role of α‐Phase Nucleation Before Thermal Annealing

AbstractUpscaling the coating of formamidinium lead triiodide (FAPbI3) thin film is essential to realizing full printing and thereby roll‐to‐roll production of perovskite photovoltaics. However, thin‐film FAPbI3 processed from antisolvent‐free, printing methods suffer from undesirable degradation to the non‐photoactive phase, particularly in ambient processing conditions. Here, the most critical stage in thin‐film processing is identified as the gas‐quenching treatment of the as‐cast wet film. It is crucial to achieve both the nucleation of α‐phase nanocrystals and their sufficient growth at room temperature, which are indispensable for templating the growth of a highly crystalline and stable α‐FAPbI3 film during subsequent thermal annealing. The gas‐quenching‐treated film without these α‐phase nanocrystals can only be converted to meta‐stable α‐FAPbI3 by thermal annealing. By precisely identifying the spontaneous doping of cesium ion (Cs+) as a key factor in triggering α‐FAPbI3 nucleation and the role of chloride ion (Cl−) in enhancing nanocrystal growth, a generalized mechanism for additive engineering for the precursor ink is theorized. The identified mechanism translates to a power conversion efficiency of 19.36% for fully printed carbon‐electrode solar cells, 16.23% for carbon‐electrode minimodules, and excellent operational stability, showing the promising potential of this proposed fabrication route in the upscaling of perovskite photovoltaics.

Influence of in-situ hydrogenation on photoelectrical properties of amorphous and nanocrystalline GeSn deposited by magnetron sputtering

This study investigates the fabrication of short-wavelength infrared (SWIR) photosensitive amorphous and nanocrystalline Ge1-xSnx:H thin films by magnetron sputtering from separate Ge and Sn targets using different Ar:H mixing ratios as working gas. Amorphous Ge1-xSnx:H films have been obtained on both c-Si and fused quartz substrates at ambient temperature, while dynamic nanocrystallization occurs in-situ when the substrate temperature during deposition is raised to 200 °C. Fourier-transform infrared spectroscopy has shown the hydrogen incorporation by detecting an absorption line at 1873 cm-1, close to the value corresponding to Ge-H bonding, only in the room temperature amorphous films. Based on that, we infer that the hydrogen concentration is very low in the films deposited at high temperature. The higher concentration of hydrogen in the amorphous samples is associated with an increase of the absorption gap to 0.5eV compared to 0.3eV in the 200oC samples. In-situ (during deposition) and ex-situ (by subsequent rapid thermal annealing) nanocrystallization have been analyzed by high-resolution transmission electron microscopy, X-ray diffraction and micro-Raman spectroscopy. SWIR spectral photosensitivity up to 2.4µm was found to be more than two orders of magnitude improved in hydrogenated amorphous films with high hydrogen content, compared to the nanocrystalline ones that are weakly hydrogenated. These findings demonstrate the potential of hydrogenation to enhance the photoelectric properties of GeSn sputtering films for optoelectronic SWIR infrared applications.

Ultralight M5 aerogels with superior thermal stability and inherent flame retardancy.

Ultra-lightweight materials often face the formidable challenge of balancing their low density, high porosity, high mechanical stiffness, high thermal and environmental stability, and low thermal conductivity. This study introduces an innovative method for synthesizing high-performance polymer aerogels to address the challenge. Specifically, we detail the production of poly (2,5-dihydroxy-1,4-phenylene pyridine diimidazole) (PIPD or M5) aerogels. This process involves chemically stripping M5 "super" fibers into nanofibers, undergoing a Sol-Gel transition, followed by freeze-drying and subsequent thermal annealing. The M5 aerogels excel beyond existing polymer aerogels, boasting an ultralight density of 6.03 mg cm-3, superior thermal insulation with thermal conductivity at 32 mW m-1 K-1, inherent flame retardancy (LOI = 50.3%), 80% compression resilience, a high specific surface area of 462.1 m2 g-1, and outstanding thermal stability up to 463 °C. These multi-faceted properties position the M5 aerogel as a front-runner in lightweight insulation materials, demonstrating the strategic use of high-performance polymer assembly units in aerogel design.

Pre-deformation assisted fabrication of bulk Nd2Fe14B/α-Fe nanocomposites with high energy density

For Nd2Fe14B/α-Fe nanocomposite magnets, which exhibit great superiority in theoretical energy products, it is a great challenge to obtain controlled nano-scale microstructural features while eliminating the harmful metastable phases due to the general metastable fabrication methods. Here, we report a strategy to control the nano-scale features and simultaneously eliminate metastable phases for Nd2Fe14B/α-Fe nanocomposites through low-temperature pre-deformation of amorphous alloys combined with subsequent thermal annealing. The resultant bulk Nd2Fe14B/α-Fe nanostructure exhibits desired ultrafine grain sizes, ∼20 nm for soft-magnetic α-Fe phase with a high fraction of Vα-Fe ≈ 30 wt% and ∼33 nm for hard-magnetic Nd2Fe14B phase. The desired microstructure results in a larger coercivity (Hci = 4.1 kOe) and higher saturation magnetization (Ms = 1.51 T) compared to those (Hci = 3.3 kOe and Ms = 1.35 T) of the counterpart without pre-deformation, contributing to a high energy density of 26.3 MGOe. This energy density is 200% larger than that of the counterpart without pre-deformation and far beyond that (around 20 MGOe) of previously reported bulk Nd2Fe14B/α-Fe nanocomposites with Vα-Fe ≥ 20 wt%. The superior property stems from the purposely introduced low-temperature pre-deformation that changed the structure and local chemistry of the amorphous alloy, facilitating the decomposition of harmful metastable phases and the formation of Nd2Fe14B phase during annealing processes, which lowers the temperature, from 750 to 700 °C for producing the Nd2Fe14B/α-Fe nanostructure and thus yields ultrafine nanograins. These results demonstrate an effective means to prepare high-performance bulk Nd2Fe14B/α-Fe nanocomposite magnets.

Structural evolution of zirconium diboride under gamma irradiation and thermal annealing

Understanding the thermal properties and enhancing the performance of zirconium diboride (ZrB2) under extreme conditions is crucial, especially given its role as a burnable absorber in nuclear fuel pellets and its potential applications in accident-tolerant fuels. This study explores the structural alterations of ZrB2 crystals induced by gamma irradiation and subsequent thermal annealing. ZrB2 crystals were exposed to absorption doses of 300 kGy, 1000 kGy, 1500 kGy, and 3000 kGy using a 60Co gamma source, followed by thermal treatment at 1173 K under vacuum conditions. Also, Monte Carlo simulations were utilized to analyze the energy deposition and distribution of gamma quanta within the material during irradiation, highlighting Compton effects up to 0.23 MeV. X-ray diffraction analysis elucidated the impact of gamma radiation on ZrB2 crystal lattice parameters, space group, and volume expansion coefficient. Post-irradiation analysis revealed a maximum degree of amorphization and investigated mechanisms governing lattice parameter expansion. Thermal annealing at 1173 K significantly enhanced crystallinity, reducing amorphization to 0.2 % at an absorption dose of 3000 kGy and facilitating the restoration of the crystal's columnar structure. This comprehensive investigation provides insights into the intricate interplay between gamma irradiation, thermal processing, and resulting structural changes in ZrB2 nanocrystals, essential for applications in radiation-exposed environments.

Pentaerythritol-DOPA (PE-DOPA): A tetra-catechol derivative for versatile hydrophilic nanocoatings

Pentaerythritol (PE) was modified with 3,4-dihydroxy-L-phenylalanine (L-DOPA) to produce a tetra(catecholamine) tetra-ester derivative (PE-DOPA). Subsequently, PE-DOPA was used to dip-coat glass, stainless steel (SS) and various plastics under alkaline conditions and formed a poly(PE-DOPA) surface coating ranging in thickness between 1.0–3.0 nm on glass and 9.0–12.0 nm on SS, as estimated by X-ray photoelectron spectroscopy (XPS). The as-coated poly(PE-DOPA) showed increased hydrophilicity compared to the bare substrate, as demonstrated by water contact angle (WCA) measurements, whilst subsequent thermal annealing of poly(PE-DOPA) coatings on glass and SS at 120 °C for 6 h reversed the as-coated hydrophilicity through an indole ring formation reaction. The molecular structure of the poly(PE-DOPA) coating was investigated by adsorption studies, suggesting monolayer formation on glass and multilayer on SS. Surface modification of plastic substrates (e.g. Nylon, polyester, polyolefines, PTFE) was also confirmed at the molecular level by XPS and at bulk properties level by WCA. PTFE was the only plastic substrate that didn’t show any altering of its bulk hydrophilicity. Lastly, the fabrication of multilayer structures where poly(PE-DOPA) was coated by bovine serum albumin (BSA) allowed for a first assessment of poly(PE-DOPA) affinity for BSA and the associated possibility of tailoring poly(PE-DOPA) response.

Phase formation, structure and properties of quaternary MAX phase thin films in the Cr-V-C-Al system: A combinatorial study

Tailoring of individual atomic layers via alloying to synthesize quaternary MAX phases allows for expanding their chemical diversity and fine-tuning of their properties. In this study, Cr-V/C/Al multilayered precursors were deposited via combinatorial magnetron sputtering, creating nanostructured architectures with periodic stacking of nanolayers and varying Cr:V ratios. Their phase transformation and underlying reaction mechanisms during subsequent thermal annealing in argon towards the prospective quaternary solid solution (CrV)n+1AlCn MAX phases formation was systematically studied. Crystallization of (CrV)2AlC starts at approximately 500°C, while growth of higher-ordered (CrV)4AlC3 is observed from 960°C. Notably, intergrowth of (CrV)2AlC and (CrV)4AlC3 structures with coherent interface suggests that (CrV)2AlC acts as template for nucleation of (CrV)4AlC3. Thermal stability and high-temperature oxidation tests found that (CrV)2AlC exhibits higher thermal stability compared to (CrV)4AlC3 and films with Cr72.7V27.3 displayed good oxidation resistance at 1000°C, forming a protective bilayer oxide scale consisting of (Cr,Al)2O3 and Al2O3.

Repairing surface defects of carbon fibers: Electrostatic spraying nano-carbons on stabilized PAN-fibers and subsequent thermal annealing

The introducing of nanomaterials on the carbon fibers (CFs) surface is an effective method for repairing surface defects. Due to the chemical inertness of CFs surface, the bonding force between reinforcing material and CFs is weak. In this paper, nano-carbons (graphene oxide and graphene quantum dots) were assembled to defects on surface of stabilized fibers (SFs) through electrostatic spraying assisted by airflow and then thermally annealed to enhance bonding force between nano-carbons and fibers. The distribution of nano-carbons on fibers surface was explored and it was found that the nano-carbons were directionally covered on or filled in defects on fibers surface to reduce specific surface area and pore volume. The chemical structures on fiber surface were discussed by X-ray photoelectron spectroscopy and atomistic ReaxFF molecular dynamics simulation, and it suggested that covalent crosslinking occurred between CFs surface and nano-carbons. And further, the nano-scratch on fibers surface revealed a significant increase in the bonding force between nano-carbons and fiber after thermal annealing. The maximum tensile strength and Young´s modulus of CFs with nano-carbons increased 24.36% and 38.63%, respectively. Subsequently, the finite element simulation ABAQUS was adopted to demonstrate that the addition of nano-carbons alleviated stress concentration at defects on CFs surface. At the same time, the smaller stress and stress diffusion were found in CFs reinforced by graphene oxide than that with graphene quantum dots.

Sustainable conversion of vine shoots and pig manure into high-performance anode materials for sodium-ion batteries

Sodium-ion batteries (SIBs) are considered promising candidates for future grid energy storage, with hard carbons emerging as key commercial anode materials. This study presents a novel approach to synthesize N-doped hard carbons via co-hydrothermal treatment of vine shoots and pig manure and subsequent thermal annealing of the resulting hydrochar. This method enhances the development of micro- and ultra-microporosity in the synthesized hard carbons, with nitrogen, and to a lesser extent phosphorus and sulfur, introduced as doping elements. Furthermore, the incorporation of hydrochloric acid during the hydrothermal step promotes biomass hydrolysis, leading to increased mesoporosity and the formation of microsphere clusters. In the realm of electrochemical performance, an investigation into various ester- and ether-based electrolytes has revealed NaPF6 in diglyme as the best formulation, thanks to its thinner and more stable solid electrolyte interface (SEI). Using this electrolyte, the best-performing electrode showed an initial Coulombic efficiency (ICE) of 73 %, with reversible capacities of 239, 180, 86, and 57 mAh g−1 at 0.1, 1, 5, and 10 A g−1, respectively. In addition, the electrode exhibited a remarkable capacity retention of 88 % after 250 cycles as well as a compatible behavior when paired with a NVPF-based cathode.

Effect of Bi2MoO6 Morphology on Adsorption and Visible-Light-Driven Degradation of 2,4-Dichlorophenoxyacetic Acid.

The development of highly efficient and stable visible-light-driven photocatalysts for the removal of herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) from water is still a challenge. In this work, Bi2MoO6 (BMO) materials with different morphology were successfully prepared via a simple hydrothermal method by altering the solvent. The morphology of the BMO material is mainly influenced by the solvent used in the synthesis (H2O, ethanol, and ethylene glycol or their mixtures) and to a lesser extent by subsequent thermal annealing. BMO with aggregated spheres and nanoplate-like structures hydrothermally synthesized in ethylene glycol (EG) and subsequently calcined at 400 °C (BMO-400 (EG)) showed the highest adsorption capacity and photocatalytic activity compared to other synthesized morphologies. Complete degradation of 2,4-D on BMO upon irradiation with a blue light-emitting diode (LED, λmax = 467 nm) was reached within 150 min, resulting in 2,4-dichlorophenol (2,4-DCP) as the main degradation product. Holes (h+) and superoxide radicals (⋅O2-) are assumed to be the reactive species observed for the rapid conversion of 2,4-D to 2,4-DCP. The addition of H2O2 to the reaction mixture not only accelerates the degradation of 2,4-DCP but also significantly reduces the total organic carbon (TOC) content, indicating that hydroxyl radicals are crucial for the rapid mineralization of 2,4-D. Under optimal conditions, the TOC value was reduced by 84.5% within 180 min using BMO-400 (EG) and H2O2. The improved degradation performance of BMO-400 (EG) can be attributed to its particular morphology leading to lower charge transfer resistance, higher electron-hole separation, and larger specific surface area.

Improving Hydrogen Release From Oxygen‐Functionalized LOHC Molecules by Ru Addition to Pt/C Catalysts

AbstractBimetallic PtRu/C catalysts have been prepared by depositing Ru onto a commercial Pt/C catalyst and subsequent thermal annealing. Different Pt : Ru ratios of 1 : 1, 2 : 1, 4 : 1, 8 : 1, and 16 : 1 have been investigated with annealing temperatures of 350 and 500 °C. Using X‐ray diffraction (XRD), synchrotron powder X‐ray diffraction (SPXRD) combined with pair distribution function (PDF) analysis and scanning transmission electron microscopy with energy dispersive X‐ray spectrum imaging (STEM‐EDXS), we show that diffusion of Ru into the fcc crystal structure of the Pt nanoparticles takes place during thermal annealing. Partial segregation and the formation of Pt nanoclusters on the bimetallic surface was observed depending on the Pt : Ru ratio. The annealing process does not only cause a high Pt dispersion but also affects the electronic structure of the Pt surface by broadening the d‐band thus facilitating the product's desorption from the surface of the bimetallic particle. These beneficial effects have been exemplified for the catalytic dehydrogenation of dicyclohexylmethanol, a promising hydrogen carrier compound with 7.2 wt% hydrogen capacity. The most active catalyst material among the tested supported alloys and monometallic reference materials was Pt4Ru1/C after annealing at 500 °C, which increased the hydrogen release productivity by 65 % compared to the unmodified Pt/C catalyst.

Improvement in Performance and Stability of PbS QD/IGZO Phototransistors Through the Introduction of Ga2O3 Film for Broadband Sensor Applications.

The development of broadband photosensors has become crucial in various fields. Indium-gallium-zinc oxide (IGZO, In:Ga:Zn = 1:1:1) phototransistors with PbS quantum dots (QDs) have shown promising features for such sensors, such as reasonable mobility, low leakage current, good photosensitivity, and low-cost fabrication. However, the instability of PbS QD/IGZO phototransistors under an air atmosphere and prolonged storage remain serious concerns. In this article, two concepts to improve the reliability of PbS QD/IGZO phototransistors were implemented. P-type doping in the PbS QD layer through oxidation allows increasing the built-in potential between IGZO and PbS QDs, leading to enhancement in photoinduced electron-hole pair creation. Second, agglomeration and fusion of a PbS QDs layer were controlled via thermal annealing, which facilitated the transport of photocreated carriers. The p-type doping and interconnection of a PbS QD layer can be achieved by deposition and subsequent thermal annealing of gallium oxide (Ga2O3) on PbS QD/IGZO stacks. The resulting Ga2O3/PbS QD/IGZO phototransistors exhibited high-performance switching characteristics under dark conditions. Notably, they showed a remarkable photoresponsivity of 196.69 ± 4.05 A/W and a detectivity of (5.47 ± 1.4) × 1012 Jones even at a long-wavelength illumination of 1550 nm. While the unpassivated PbS/IGZO phototransistor suffered serious degradation in optical performance after 2 weeks of storage, the Ga2O3/PbS QD/IGZO phototransistor demonstrated enhanced stability, maintaining high performance for over 5 weeks. These findings suggest that Ga2O3/PbS QD/IGZO phototransistors offer a feasible approach for the fabrication of large-scale active matrix broadband photosensor arrays, potentially revolutionizing optical sensing in various cutting-edge applications.

Thermally stable photoluminescence centers at 1240 nm in silicon obtained by irradiation of the SiO2/Si system

The study of light-emitting defects in silicon created by ion implantation has gained renewed interest with the development of quantum optical devices. Improving techniques for creating and optimizing these defects remains a major focus. This work presents a comprehensive analysis of a photoluminescence line at a wavelength of 1240 nm (1 eV) caused by defects arising from the ion irradiation of the SiO2/Si system and subsequent thermal annealing. It is assumed that this emission is due to the formation of defect complexes WM with trigonal symmetry similar to the well-known W-centers. A distinctive feature of these defects is their thermal resistance up to temperatures of 800 °C and less pronounced temperature quenching compared to the W-line. The difference in the properties of these defect centers and W-centers can be explained by their different defect environments, resulting from the larger spatial separation between vacancies and interstitial atoms diffusing from the irradiated layer. This, in turn, is associated with the difference in the distribution of primary radiation defects during irradiation of the SiO2/Si system and silicon not covered with a SiO2 film. The patterns of changes in the WM line depending on various factors, such as the thickness of the SiO2 film, type of conductivity and impurity concentration in the original silicon, irradiation parameters, and annealing regimes, is studied and explained in detail. These findings demonstrate the benefits of this new approach when compared to previous methods.

Suppression of helium migration in arc-melted and 3D-printed CoCrFeMnNi high entropy alloy

We compare the evolution and migration of helium cavities in 3D-printed and arc-melted CoCrFeMnNi high entropy alloys (HEAs), and 304 stainless steel (SS), using transmission electron microscopy (TEM). The materials are subjected to Ni and He sequential implantation as well as subsequent thermal annealing. After irradiation at room temperature, all samples initially display similar He cavity sizes. Annealing up to 673 K has a minimal impact on cavity size. However, annealing at 873 K leads to significant cavity growth. Both HEA materials exhibit larger average cavity sizes compared to 304 SS, while a higher proportion of small cavities is found in the 304 SS. This indicates that Ostwald Ripening is more prevalent in 304 SS, confirmed by in-situ thermal annealing in TEM. Depth distribution analysis reveals distinct cavity belts after annealing: from the narrowest in 3D printed HEA to the broadest belts in 304 SS. These results indicate that the He concentration at the peak of irradiation damage decreases in the same order. We suggest that the long-range migration of He atoms is limited in both the Cantor and 3D-printed Cantor HEAs, potentially due to the complex diffusion paths of the He atoms.

P-type Gallium nitride creation through O+ implantation

P-type GaN was successfully achieved by vertically implanting positive monovalent cations of oxygen (O[Formula: see text]) into undoped (native n-type with an electron concentration of [Formula: see text][Formula: see text]cm[Formula: see text]) (0001) monocrystalline GaN. This implantation was carried out with an energy of 200[Formula: see text]keV and a dose of [Formula: see text] ions/cm2. In the absence of subsequent rapid thermal annealing (RTA) or when exposed to RTA at 950°C for 10[Formula: see text]s in a nitrogen ambient environment, temperature-dependent Hall measurements in a vacuum consistently indicated stable p-type conductivity. For the sample that underwent subsequent RTA, the room-temperature Hall hole concentration measured [Formula: see text][Formula: see text]cm[Formula: see text], the Hall resistivity was 0.44[Formula: see text][Formula: see text][Formula: see text]⋅[Formula: see text]cm, the Hall hole mobility reached 17.81[Formula: see text]cm2[Formula: see text]⋅[Formula: see text]V[Formula: see text][Formula: see text]⋅[Formula: see text]s[Formula: see text], and the acceptor ionization energy was determined to be 0.08[Formula: see text]eV. The doping efficiency was calculated at 5.5%. O[Formula: see text] ions effectively serve as acceptors, whether annealed or not. The p-type conductivity induced by O[Formula: see text] implantation in GaN is notably advantageous and holds practical significance for the ongoing development of future device technology.

Tellurization of Pd(111) revisited: Formation of a TePd[formula omitted] surface alloy but no PdTe[formula omitted] monolayer

In a recent publication [2D Materials, 8, 045033 (2021)], it was reported that the growth of a monolayer PdTe2 in ultra-high vacuum could be achieved by deposition of tellurium on a palladium (111) crystal surface and subsequent thermal annealing. By means of low-energy electron diffraction intensity (LEED-IV) structural analysis, we show that the obtained 3×3R30° superstructure is in fact a TePd2 surface alloy. Attempts to produce a PdTe2 layer in ultra-high vacuum by increasing the Te content on the surface were not successful.

Electrochemical Etching of Nitrogen Ion‐Implanted Gallium Nitride – A Route to 3D Nanoporous Patterning

Dopant‐selective electrochemical etching (ECE) of gallium nitride (GaN) results in well‐defined porous layers with tunable refractive index, which is extremely interesting for integrating photonic components into nitride technology. Herein, the impact of nitrogen implantation with and without subsequent rapid thermal annealing (RTA) on the porosification process of highly n‐doped GaN ([Si] 3 × 1019 cm−3) is investigated. Implantation is expected to compensate the donors of the n‐GaN layer to spatially suppress porosification during ECE. Optical transmission, electrochemical capacitance–voltage, and X‐Ray diffractometry of as‐grown and as‐implanted GaN suggest successful compensation of n‐dopants. Cross‐sectional scanning electron microscopy reveals the presence of mesopores (diameter 2–50 nm) after ECE of the as‐grown n‐GaN. In the case of implanted n‐GaN, it is found that ECE results in macropores (diameter > 50 nm), which can be suppressed by an intermediate RTA step. The implanted and annealed n‐GaN layers solely exhibit mesopores at the top and bottom, while the intermediate region remains unimpaired. Chronoamperometry and gravimetry provide additional insight and confirm the presence of macro‐ and mesopores in samples without and with RTA, respectively. The results demonstrate a successful implementation of etch‐resisting subsurface layers, which are required for 3D refractive index engineering in porous GaN.

Effects of ion implantation with arsenic and boron in germanium-tin layers

Ion implantation is widely used in the complementary metal–oxide–semiconductor process, which stimulates to study its role for doping control in rapidly emerging group IV Ge1−xSnx materials. We tested the impact of As and B implantation and of subsequent rapid thermal annealing (RTA) on the damage formation and healing of the Ge1−xSnx lattice. Ion implantation was done at 30, 40, and 150 keV and with various doses. The implantation profiles were confirmed using secondary ion mass spectrometry. X-ray diffraction in combination with Raman and photoluminescence spectroscopies indicated notable crystal damage with the increase of the implantation dose and energy. Significant damage recovery was confirmed after RTA treatment at 300 °C and to a larger extent at 400 °C for a Ge1−xSnx sample with Sn content less than 11%. A GeSn NP diode was fabricated after ion implantation. The device showed rectifying current-voltage characteristics with maximum responsivity and detectivity of 1.29 × 10−3 A/W and 3.0 × 106 cm (Hz)1/2/W at 77 K, respectively.

Vanadyl Sulfate Based Hole‐Transporting Layer Enables Efficient Organic Solar Cells

Comprehensive SummaryIt remains an urgent task to develop alternative hole‐transporting layer (HTL) materials beyond commonly used PEDOT:PSS to increase the shelf‐life of organic solar cells (OSCs). Inorganic metal oxide type materials, such as NiOx, CoOx and VOx, with suitable work functions have attracted numerous research attention recently. In this work, more abundant and easily accessible oxygenated salt, vanadyl sulfate (VOSO4) has been demonstrated to be excellent choice as HTL for OSCs. The VOSO4‐based HTL can be readily processed by spin‐coating from the precursor solution with subsequent thermal annealing and UVO treatment. As a consequence, a high power conversion efficiency (PCE) of 18.72% can be achieved for PM8:L8‐BO based OSCs with the VOSO4‐based HTL. High transmittance, smooth film surface, suitable energy level and high conductivity were revealed to contribute to the high OSC performance. More importantly, compared to device with PEDOT:PSS, VOSO4‐based OSCs exhibit improved stability when stored in the N2 filled glove box. After being stored for 600 h, VOSO4‐based device can retain 89% of its initial efficiency. Notably, VOSO4 can be used as general HTL in PM6:BTP‐BO‐4Cl and PM6:IT‐4F based OSCs, yielding high PCEs of 17.87% and 13.85%, respectively.

The effect of microstructure on recovery and recrystallization after annealing of two neutron irradiated ITER specification tungsten

The study of the recrystallization resistance of engineering grade tungsten (W) prior to and after neutron irradiation as well as subsequent thermal annealing provides valuable insight into neutron induced defect interactions and their kinetics as well as their correlation with recrystallization mechanisms. The outcome of such investigations would be of assistance for appropriate grade selection for a fusion reactor and the design of healing processes enabling the lifetime extension of fusion reactor components. Within this framework, samples from ITER specification W, forged bar and cold-rolled plate, were neutron irradiated to a dose of 0.18 dpa at 600 °C in the Material Test Reactor BR2, Mol, Belgium, and subsequently isochronally annealed from 700 to 1550 °C for 24 h with a 50 °C step with two non–irradiated counterparts. X-ray diffraction, optical microscopy and positron annihilation lifetime spectroscopy, combined with Vickers Hardness are used to correlate the recrystallization process and recovery mechanisms. It is found that the non-irradiated plate has a higher recrystallization resistance compared to that of the bar, with the former requiring 100 °C higher temperature for 24 h annealing time to recrystallize. Despite the irradiation induced dislocation loops and voids being of similar sizes and densities for both grades, the different initial microstructure affects the recrystallization process upon annealing, delaying it by 50 °C on the plate. Further in the plate a complete void dissolution is observed before recrystallization, which is not the case for the bar, for which the two effects occur at the same temperature.