We report an ultrafast mechanochemical synthesis of Ni1_xCoxS (0 <= x <= 1) electrocatalysts via a mechanically induced self-propagating reaction (MSR). This solvent-free route produces catalysts directly from elemental precursors in just 30 s of high-energy ball milling, without any subsequent calcination or washing steps. Among the synthesized compositions, Ni0 & sdot;4Co0 & sdot;6S exhibited superior hydrogen evolution reaction (HER) performance in alkaline media, achieving a competitive overpotential of 237 mV at 10 mA cm_ 2 on an inert glassy carbon electrode and retaining 92% activity over 24 h. The enhanced performance is attributed to the formation of a highly interconnected heterointerface between Ni-incorporated cubic Co9S8 and hexagonal CoS phases. This unique configuration provides abundant active sites and promotes the 'electron hopping' mechanism, effectively balancing water dissociation and hydrogen adsorption steps to accelerate alkaline HER kinetics. The combination of scalable, eco-friendly synthesis and high intrinsic activity positions Ni0 & sdot;4Co0 & sdot;6S as a promising candidate for commercial anion exchange membrane (AEM) electrolyzers.

Pre-catalysts are gaining significant attention as highly tunable materials capable of generating abundant active sites during operation. In this work, we explore a series of transition metal nitroprussides containing Ni, Co, and/or Cu for the electrochemical urea oxidation reaction (UOR), as part of a hybrid water electrolysis strategy. The structural evolution of these pre-catalysts under electrochemical conditions is tracked using electrochemical analyses, in situ spectroscopy, and complementary ex situ characterization. Dynamic changes in the active sites are monitored through in situ X-ray absorption and Raman spectroscopy, while reaction intermediates are identified via in situ infrared spectroscopy. The intrinsic flexibility and structural lability of nitroprusside pre-catalysts enable systematic probing of how transition metals influence catalytic behaviour. The electro-converted catalyst exhibits remarkable stability, sustaining current densities exceeding 400 mA cm-2 for over 80 h of continuous operation in an anion exchange membrane (AEM) electrolyzer. The incorporation of suitable transition metals is found to tune the oxidizability and redox interconversion of Ni species, serving as a key descriptor for UOR activity. Overall, this work highlights nitroprusside pre-catalysts as versatile systems for elucidating structure-activity relationships in electrocatalytic reactions involving dynamically evolving active sites and for demonstrating the critical role of dopants.

Understanding electrocatalyst activation and degradation under realistic operating conditions requires operando spectroscopic techniques capable of probing solid-liquid interfaces with running electrochemistry. Here, we present the design and implementation of a versatile operando electrochemical X-ray Photoelectron Spectroscopy (XPS) platform compatible with aqueous environments and controlled current- or potential-driven operation. The modular cell architecture enables both conventional three-electrode half-cell measurements as well as a two-electrode setup for zero-gap proton-exchange membrane or anion-exchange membrane water electrolysis at high current densities. Key design considerations, including electrolyte management, membrane integration into the cell, gas handling, and X-ray access geometry, are discussed in detail. The platform allows investigation of catalyst oxidation, hydroxylation, reduction, and surface restructuring under realistic electrochemical conditions. Representative measurements demonstrate stable operation during high-current water electrolysis as well as flexibility for broader electrocatalytic studies. This protocol provides a practical framework for implementing operando XPS in electrochemical research laboratories and facilitates reproducible investigation of dynamic catalyst transformations at electrified interfaces.

Reducing the iridium content while preserving the activity and robustness of anode catalysts remains a central challenge for Proton Exchange Membrane Water Electrolysis (PEM-WE). In this work, we demonstrate that controlled lattice distortion – introduced during magnetron co-sputtering – can serve as a powerful materials-design parameter for Ir–Co catalysts. By adjusting the conditions of the plasma deposition process, we prepare a series of thin-film Ir–Co layers exhibiting systematically varied strain states and defect densities. The catalysts are evaluated through single-cell PEM-WE testing, complemented by ex-situ and operando characterization including X-ray photoelectron spectroscopy (XPS), wide-angle X-ray diffraction, and Scanning Photoelectron Microscopy (SPRES). The combined dataset reveals that increased lattice distortion changes the process of subsurface oxidation of Ir into IrOx, which leads to improved activity and stability both in the PEM-WE and half-cell measurements. Our results highlight strain modulation during magnetron sputtering as a scalable and tunable strategy for designing high-performance, low-Iridium catalysts. This approach provides a clear structure–property link and opens new opportunities for engineering thin-film PEM-WE anodes beyond composition alone.

Surface activation of transition metal chalcogenides (TMCs) is commonly attributed to electrochemical reduction and defect formation under applied bias. Herein, we demonstrate that for single-crystalline NiSeTe, a significant fraction of the surface transformation typically associated with electrochemical activation instead arises from purely chemical, sulfuric acid-driven (H2SO4) reconstruction occurring prior to any applied potential. Nearambient pressure X-ray photoelectron spectroscopy (NAP-XPS) is employed to monitor the evolution of pristine, acid-exposed, and washed surfaces. Acid treatment selectively removes native TeOx species and Ni-O(H) environments, while heterogeneous sulfate-derived species collapse into a transient S(VI)-rich adlayer. Subsequent washing eliminates weakly bound sulfates and yields a chemically simplified, oxide-free NiSeTe surface with a thin, stable sulfate termination. Notably, operando, bias-controlled NAP-XPS measurements with simultaneous chronoamperometric current monitoring reveal that cathodic polarization under HER-relevant conditions does not further reduce the acid-reconstructed surface, indicating that sulfuric acid exposure already generates an oxide-free NiSeTe termination prior to electrochemical biasing. In contrast, anodic polarization under OER-relevant conditions promotes tellurium re-oxidation. These findings establish acid-driven chemical restructuring as a dominant contributor to surface activation in NiSeTe and underscore the importance of disentangling chemical and electrochemical effects in chalcogenide electrocatalysts.

Strain engineering in single-crystalline oxide membranes offers a versatile platform to tailor functional properties beyond thin films or bulk materials. However, accurately determining strain transfer and distribution within these membranes remains challenging, limiting direct correlations between structural distortion and functional response and hindering the rational design of flexible devices. Here, high-resolution synchrotron x-ray diffraction is used for in situ monitoring of strain in (001)-oriented La 0.7 Sr 0.3 MnO 3 membranes on flexible polymer substrates under stretching and bending. This approach enables quantitative determination of in-plane strain as both macroscopic averages and spatially resolved maps. Macroscopic analysis shows that strain transfer is most efficient in thinner films and leads to distinct strain symmetries under stretching and bending. Spatially resolved measurements reveal local strain heterogeneity that increases with applied stress beyond macroscopic averages. Correlating strain distribution with estimated Curie temperature shifts illustrates how such heterogeneity could translate into spatially non-uniform functional behavior. Additionally, the setup's sensitivity to crystallographic orientation enables analysis of stacked and twisted architectures, where interlayer strain transfer is effective yet attenuated with distance from the substrate. Altogether, this framework establishes a robust approach for probing oxide membranes, opening pathways toward strain-engineered flexible devices, multilayer heterostructures, and operando investigations.

The development of advanced iridium oxide (IrO x ≤ 2) electrocatalysts for the oxygen evolution reaction (OER) remains limited by insufficiently defined structure-property relationships. Here, using operando X-ray diffraction and in-house synthesized unsupported mesoporous IrO x nanoparticles with controlled crystallinity, size, and oxidation state, alongside a commercial benchmark material, we show reversible IrO 2 lattice structure and Ir oxidation state changes across cell voltages ranging from 0.05 V to 2.00 V. At low potentials (E < 0.25 V), the IrO 2 surface partially amorphizes, linked to formation of a poorly conductive iridium oxyhydroxide (IrO (1-δ) (OH) (1+δ) ) phase. Under OER conditions, the IrO 2 lattice contracts and Ir-O bond distances shorten. Density functional theory calculations support these reversible structural and chemical transformations and explain their mechanistic origin, while on-line inductively coupled plasma mass spectrometry measurements directly correlate these changes with Ir dissolution dynamics. Extending to practical conditions, a proton exchange membrane water electrolyzer (PEMWE) operated for 500 h at 2 V shows that an initially amorphous IrO x catalyst crystallizes, ultimately degrading to performance and Tafel slopes comparable to those of rutile IrO 2 . These findings highlight the redox-driven structural flexibility of IrO x materials and link IrO 2 structure, chemistry, OER activity, and Ir dissolution during start–stop operation in PEMWEs.

Transition metal borides (TMBy) represent a structurally rich group of materials with attractive physical properties, including high hardness and high melting points, making them promising candidates for applications in extreme conditions. Considerable attention has been paid to overstoichiometric TMB2+Delta films with hexagonal alpha-P6/mmm structure exhibiting super-hardness attributed to high cohesive strength between excess-boron tissue phase and crystalline nanocolumns. However, positive effects of reducing the boron content in terms of toughness and oxidation resistance have been reported. Lowering the boron to metal ratio can have various effects on structure and stability, depending on the specific diboride system and its affinity to boron vacancies. In this work, we study the influence of boron understoichiometry on structure and thermal stability of vanadium tungsten diboride films. We present results of high-resolution scanning transmission electron microscopy showing that boron deficiency leads to a high density of planar defects, including anti-phase boundaries (APB- 2i), the accumulation of which enables the formation of WB-Cmcm areas coherently included in the hexagonal VB2-P6/mmm structure. The observation is supported by density functional theory calculations showing that since the presence of vacancies is favored by the alpha-WB2 and not convenient for the alpha-VB2 system, there is an increased probability of decomposition into stoichiometric VB(2 )and boron deficient WBz<2 products. Additionally, we report on other types of planar defects, such as twinning, and discuss their role in local formation of other boride phases within the Cmcm structure.

Ir-Ru alloys with high Ru content serve as stable and highly active catalysts for the Oxygen Evolution Reaction (OER) in Proton Exchange Membrane Water Electrolyzers (PEM-WEs), enabling efficient operation with low Ir loadings (150 mu g cm-2). Despite this, the mechanisms behind their enhanced stability remain unclear. In this study, operando Wide-Angle X-ray Scattering (WAXS) and ex situ techniques are utilized to investigate the structural evolution of these magnetron-sputtered alloys during a PEM-WE operation. The findings reveal that Ru leaches from the surface upon potential application, forming a dynamic Ir-Ru@IrOx core-shell structure. The Ir shell, strained by the Ir-Ru core, maintains a lower oxidation state than pure Ir catalyst, leading to superior catalytic activity and stability. Remarkably, the Ir-Ru 25:75 catalyst demonstrates better stability over Ir-Ru 50:50, despite its higher Ru content, due to the better protection of the subsurface Ir and Ru from oxidation and dissolution. This study not only clarifies the performance-enhancing mechanisms of Ir-Ru catalysts but also suggests that other, more economical materials, such as Co or Ti, could serve as effective cores in Ir-M systems, offering a pathway to more cost-effective catalysts for PEM-WE applications.

Diborides of transition metals from group IVB (TMB2, TM = Ti, Zr) are desirable materials in demanding industrial conditions due to their excellent mechanical properties. Direct current magnetron sputtering (DCMS) leads to the growth of overstoichiometric (TMBx, x > 2) film with nanocomposite structure consisting of crystalline hexagonal TMB2 nanocolumns surrounded by a thin, amorphous boron-rich rich tissue phase. At elevated temperatures, the presence of the tissue phase has a negative effect on the films' mechanical properties and oxidation resistance. An innovative approach using effective ionization of sputtered species during high-power pulsed magnetron sputtering (HiPIMS) growth of ZrB2 films is presented. While layers grown using the conventional DCMS method are overstoichiometric (B/Zr = 2.2), the films grown by HiPIMS are understoichiometric, with a B/Zr ratio ranging from 1.6 to 1.9. In understoichiometric ZrB1.9 and ZrB1.6 films, detailed structural analysis using transmission electron microscopy revealed a nanocrystalline structure comprised of densely packed 10-20 nm wide nanograins. In addition, the understoichiometric films exhibit high hardness values above 42 GPa and improved high-temperature oxidation resistance compared to the ZrB2.2 film deposited by DCMS.

Proton Exchange Membrane Water Electrolyzers (PEM-WEs) are a key technology for green hydrogen production, however their large-scale deployment has been hindered by the reliance on noble metal catalysts, such as platinum (Pt) and iridium (Ir). In this study, we present a fully dry and scalable approach for fabricating ultra-low platinum-loaded cathodes for PEM-WE using only magnetron sputtering. The process involves a two-step approach: sputter-etching pre-treatment of the PEM surface to increase the catalyst dispersion and active surface area, followed by direct sputtering of Pt. We systematically investigate Membrane Electrode Assemblies (MEAs) with Pt loadings ranging from around 3.7 mu gPt cm-2 to 480 mu gPt cm-2, achieving significant performance improvement over the commercial electrodes, while reducing the Pt loading to half. Moreover, MEAs with Pt loadings around 20 mu g cm-2 exhibited excellent initial performance of approximately 2500 mA cm-2, but their stability proved to be a critical challenge. Comprehensive Electrochemical Impedance Spectroscopy (EIS) reveals key degradation mechanisms in Pt thin films, including insufficient lateral conductivity and catalyst detachment. This work provides valuable insights into the optimization of sputtered low-loading catalysts for the cathode of PEM-WE, and the analysis of the degradation pathways opens up a possibility to further stabilize the ultra-low catalyst loadings.

LiNi0.8Mn0.1Co0.1O2 (NMC811) is one of the most promising cathode materials for high energy density Li-ion batteries (LiBs). However, NMC811 suffers from capacity fading during electrochemical cycling because of its structure instability at voltages >4.2 V vs Li|Li+ due to the known hexagonal H2→H3 phase transition. Zr doping has proven to be effective in enhancing electrochemical performances of the NMC811. In depth investigations are conducted through operando x-ray diffraction (XRD) and ex situ x-ray absorption spectroscopy (XAS) measurements to mechanistically understand the benefits of Zr-doping in a NMC811 material when doped during the co-precipitation step. Herein, Zr-doping in NMC811 reduces the formation of the detrimental H3 phase and mitigates the transition metal dissolution upon cycling.

Large-scale commercialization of proton exchange membrane water electrolysis (PEM-WE) requires a catalyst for the oxygen evolution reaction (OER) that is stable, highly active, and cost-effective. Although RuO₂ demonstrates excellent OER activity, its lack of stability limits its practical application. In contrast, IrO₂ is highly stable but suffers from lower activity and is also expensive [1]. However, bimetallic oxides of Ir and Ru offer both activity and stability. Furthermore, partially substituting Ir with Ru significantly reduces the overall cost of the catalyst. This study aims to evaluate the relationship between OER activity and stability for Ir-Ru alloys with varying metallic compositions. Furthermore, it seeks to establish correlations between the morphological and structural evolution of Ir-Ru bimetallic catalysts and their catalytic performance in PEM-WE. Bimetallic layers of Ir-Ru were deposited on etched Nafion membranes using the magnetron co-sputtering method. Magnetron co-sputtering enables the preparation of bi-metallic layers with precise compositions by varying the sputter deposition power of each target [2]. Scanning transmission electron microscopy- Energy dispersive x-ray spectroscopy (STEM-EDX) analysis of the as-prepared surface revealed the complexity of the magnetron-sputtered bimetallic surface, which was highly inhomogeneous. To fully comprehend the dependence of catalytic properties on metallic ratios, crystal structure analysis was performed on samples with ten different Ir-Ru ratios, ranging from 100% Ir to 100% Ru. The crystal structure of the alloys is not a single phase but rather a combination of hcp and fcc phases. The structure of a catalyst in its as-prepared state often differs significantly from the active form it adopts under an applied potential. To fully understand this phenomenon, operando wide-angle X-ray scattering (WAXS) measurements were conducted in a fully operational PEM-WE single cell. The operando measurements allowed real-time observation of structural evolution and its correlation with the electrochemical performance of the cell and potential-driven degradation processes [3]. After the Rietveld refinement, a connection was established between the amount of Ru in the alloy and the evolution of crystallographic factors such as lattice parameter, phase fraction, and crystal structure with applied potential. Drastic changes in lattice parameters were observed immediately after the initiation of electrochemical treatment, followed by stabilization at higher potentials. Comparing operando data with the ex-situ phase diagram revealed significant Ru dissolution during the initial stages, leading to an Ir-rich surface. To explore the dissolution behavior of Ru and Ir as a function of metallic ratios, operando dissolution analysis was conducted using Scanning Flow Cell Inductively Coupled Plasma Mass Spectrometry (SFC-ICP-MS). The results clearly show that Ru dissolution rates are substantially higher than those of Ir, regardless of composition. Stability trends were explicitly described using the stability number (S-number), which quantifies the ratio of oxygen molecules evolved to the number of metal ions detected via SFC-ICP-MS [4]. The reason behind the long-term stability of alloys with a higher Ru ratio remains a key question in these studies. XPS analysis, conducted before and after electrochemical treatment, revealed that the total amount of oxides responsible for both activity (Ir³⁺) and stability (Ir⁴⁺) increase with higher Ru content. Also, SSTEM- EDX analysis after electrochemical treatment reveals the formation of a core-shell structure. The rapid initial dissolution of Ru results in the formation of an Ir-rich surface, creating a core-shell structure with a Ru-core surrounded by an Ir-enriched shell. The results from all the above-mentioned analyses lead to the conclusion that Ir oxide layer formed at the surface prevents the further dissolution of alloy, thereby providing stability to the catalyst layer. References Minke, C., Suermann, M., Bensmann, B., & Hanke-Rauschenbach, R. (2021). Is iridium demand a potential bottleneck in the realization of large-scale PEM water electrolysis?. international journal of hydrogen energy , 46 (46), 23581-23590. Hrbek, Tomáš, et al. "Sputtered Ir–Ru based catalysts for oxygen evolution reaction: study of iridium effect on stability." International Journal of Hydrogen Energy 47.49 (2022): 21033-21043 Moss, Asger B., Joel Hätinen, Peter Kúš, Sahil Garg, Marta Mirolo, Ib Chorkendorff, Brian Seger, and Jakub Drnec. "Versatile high energy X-ray transparent electrolysis cell for operando measurements." Journal of Power Sources 562 (2023): 232754. Escalera-López, Daniel, et al. "Phase-and surface composition-dependent electrochemical stability of Ir-Ru nanoparticles during oxygen evolution reaction." ACS catalysis 11.15 (2021): 9300-9316.

Titanium diboride (TiB2) is a promising candidate for high-temperature applications due to its chemical inertness, phase stability, and excellent mechanical properties. However, its typical nanocomposite microstructure with a B-tissue phase promotes low-temperature oxidation. In this study, we employ a dual approach to suppress B-tissue formation and enhance oxidation resistance: yttrium alloying, due to its strong oxygen affinity, and the use of high-power impulse magnetron sputtering (HiPIMS) to reduce boron content in the growing film. Two Ti1-xYxB2 +/-triangle coatings with similar to 9 at.% Y were deposited: overstoichiometric X-ray amorphous Ti0.68Y0.32B2.8 via conventional direct current magnetron sputtering (DCMS) and understoichiometric crystalline Ti0.76Y0.24B1.4 via HiPIMS. Thermally induced structural evolution and mechanical performance were analyzed using X-ray diffraction, scanning transmission electron microscopy, and nanoindentation. The X-ray amorphous coating crystallized above 900 degrees C into TiB2 and YB6 phases, while the HiPIMS coating retained its nanocolumnar, stacking fault-rich alpha-Ti1-xYxB2-triangle structure up to 1100 degrees C. The Ti0.68Y0.32B2.8 coating exhibited moderate hardness (similar to 28 GPa), whereas the Ti0.76Y0.24B1.4 coating reached superhardness (> 40 GPa) with higher Young's modulus (similar to 420 GPa). Both coatings showed improved oxidation resistance compared to TiB2, with delayed crystalline oxide formation above 700 degrees C, while slower oxidation kinetics was observed for the understoichiometric coating. These results demonstrate the effectiveness of alloying and highly ionized deposition techniques for tuning the structure and high-temperature performance of TiB2-based coatings.

Electrocatalytic energy conversion relies on the dynamic transformation of electrode materials into "electrocatalytically active phases" under reaction conditions. Pre-catalysts, which undergo extensive structural and chemical changes during electrochemical activation, are particularly promising in this regard. In the context of electrocatalysis, coordination complexes with labile ligands offer a unique advantage, as they can rapidly reconstruct under electrochemical conditions. Herein, a hydrazine-coordinated Ni complex embedded in a conductive carbon nanotube matrix is presented as a pre-catalyst for urea-assisted hybrid water electrolysis, that transforms into highly active γ-NiOOH nanosheets on electrochemical activation, demonstrating exceptional urea electrooxidation performance, with a low Tafel slope of 21.6 mV dec-1, a high turnover frequency (TOF) of 0.0728 s-1, and stable operation over 40 h of continuous electrolysis, reflecting superior catalytic kinetics and excellent durability. In situ synchrotron X-ray absorption, Raman, and electrochemical impedance spectroscopy reveal the dynamic evolution of active sites, the underlying reaction mechanism, and the fate of the active species after prolonged electrolysis. The integration of this pre-catalyst into an anion-exchange membrane electrolyzer highlights its potential for practical application. This work showcases the transformative role of Ni-based coordination complexes as pre-catalysts, offering an innovative blueprint for the rational design of high-performance urea oxidation electrocatalysts.

We here present a design for a versatile electrochemical cell designed for X-ray operando studies of Membrane Electrode Assembly (MEA) based electrolysis. The cell has been tested for CO2 electrolysis performance and for various X-ray techniques.

Octahedra (oh) PtNiX/C catalysts have attracted attention as cathode catalysts for proton-exchange membrane fuel cells (PEMFCs) due to their exceptional catalytic activities toward the oxygen reduction reaction. Here, we investigate the degradation dynamics of oh-PtNiIr in fuel cell conditions by operando X-ray diffraction (XRD). Two XRD-coupled square-wave accelerated stress tests (0.6 to 0.95) V and (0.7 to 0.95) V (where V is the cell voltage) confirm that, when fixing the upper limit, the dissolution and overall degradation strongly depend on the lower potential limit. By directly observing the extent of metal oxidation during potential cycling, we link the alloy redox dynamics to the stability. The studied catalysts' stability is proportional to both the extent of metal oxidation and, more interestingly, the degree of reduction. Comparing a benchmark Pt catalyst with oh-PtNiIr allows for associating the differences between oxidation and reduction potentials and the optimal usage window for each class of catalysts. This relatively simple method can be employed to find the operation boundaries of the PEMFC to minimize the degradation of a large class of Pt-based catalysts without time-consuming stress tests.

Ni-rich layered oxides LiNi1-x-yMnxCoyO2 (NMC811, x = 0.1 and y = 0.1) are considered promising cathode materials in lithium-ion batteries (LiBs) due to their high energy density. However, those suffer a severe capacity loss upon cycling at high delithiated states. The loss of performance over time can be retarded by Zr doping. Herein, a small amount of Zr is added to NMC811 material via two alternative pathways: during the formation of the transition metal (TM) hydroxide precursor at the co-precipitation step (0.1%-Zr-cp) and during the lithiation at the solid-state synthesis step (0.1%-Zr-ss). In this work, the crystallographic Zr uptake in both 0.1%-Zr-ss and 0.1%-Zr-cp is determined and quantified through synchrotron X-ray diffraction and X-ray absorption spectroscopy. We prove that the inclusion of Zr in the TM site for 0.1%-Zr-cp leads to an improvement of both specific capacity (156 vs 149 mAh/g) and capacity retention (85 vs 82%) upon 100 cycles compared to 0.1%-Zr-ss where the Zr does not diffuse into the active material and forms only an extra phase separated from the NMC811 particles.

Despite extensive efforts to reduce the costs of high-performance electrochemical devices, incorporating catalyst materials frequently falls short of achieving performance targets. Platinum alloys, known for their high oxygen reduction activity, exemplify this challenge due to integration difficulties. Here, we introduce an in situ X-ray diffraction approach to investigate structural changes in PtCo and PtNi catalysts during ink preparation. Contrary to previous assumptions that acidity is the main factor driving catalyst dissolution, our findings demonstrate that temperature plays a more critical role. Additionally, we observe rapid structural degradation during the hot-pressing of catalyst-coated membranes (CCMs), a critical yet often unavoidable processing step. These results indicate that significant catalyst deactivation can occur before operation, emphasizing the need for optimized fabrication processes. This study highlights the importance of refining ink formulation and processing protocols to fully leverage advanced materials in CCM-based energy conversion systems.

We present a successful bottom-up approach to design a generic plasma-enhanced atomic layer deposition (PEALD) supercycle recipe to grow high-quality indium gallium zinc oxide (IGZO) thin films with tunable composition at a relatively low temperature of 150 degrees C. In situ real-time ellipsometric characterization in combination with ex situ complementary techniques has been used to optimize the deposition process and quality of the films by identifying and solving growth challenges such as degree of oxidation, nucleation delays, or elemental composition. The developed supercycle approach enables facile control of the target composition by adapting the subcycle ratios within the supercycle process. Compared to other low-temperature deposition techniques resulting in amorphous films, our PEALD-IGZO process at 150 degrees C results in nearly amorphous, nanocrystalline films. The preparation of IGZO films at low temperature by a supercycle PEALD approach allows controlling the thickness, composition, and electrical properties while preventing thermally induced segregation.