Reactive Layer Research Articles

Compositional Optimization of Sputtered SnO2/ZnO Films for High Coloration Efficiency

We performed an electrochromic investigation to optimize the composition of reactive magnetron-sputtered mixed layers of zinc oxide and tin oxide (ZnO-SnO2). Deposition experiments were conducted as a combinatorial material synthesis approach. The binary system for the samples of SnO2-ZnO represented the full composition range. The coloration efficiency (CE) was determined for the mixed oxide films with the simultaneous measurement of layer transmittance, in a conventional three-electrode configuration, and an electric current was applied by using organic propylene carbonate electrolyte cells. The optical parameters and composition were measured and mapped by using spectroscopic ellipsometry (SE). Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray Spectroscopy (EDS) measurements were carried out to check the SE results, for (TiO2-SnO2). Pure metal targets were placed separately from each other, and the indium–tin-oxide (ITO)-covered glass samples and Si-probes on a glass holder were moved under the two separated targets (Zn and Sn) in a reactive argon–oxygen (Ar-O2) gas mixture. This combinatorial process ensured that all the compositions (from 0 to 100%) were achieved in the same sputtering chamber after one sputtering preparation cycle. The CE data evaluated from the electro-optical measurements plotted against the composition displayed a characteristic maximum at around 29% ZnO. The accuracy of our combinatorial approach was 5%.

Sustenance of hydrogen–oxygen cellular detonation with ozone additions in confined space

The sustenance of cellular detonation under weak confinement is studied through two-dimensional (2D) numerical simulations of hydrogen–oxygen mixtures surrounded by inert gas. The results show that in the weakly confined space, the cellular detonation with Chapman-Jouguet velocity can survive by increasing the width of the reactant layer and enhancing the reactivity of reactants, which ensures enough triple points and high reactivity in the reactant layer for detonation sustenance since transverse shocks cannot be regenerated and reinforced by boundary reflection. By adding ozone into the system and changing the width of the reactant layer, the relationship between induction length and detonation sustenance is established. It is found that the sustenance of cellular detonation in the weakly confined space is related to the ratio of the reactant layer width to the induction length. Ozone reactions can reduce the induction length and enhance reactivity, thereby promoting the generation of new transverse shocks and significantly improving the sustenance of cellular detonation in weakly confined space.

Unveiling Na‐ion storage mechanism and interface property of layered perovskite Bi2TiO4F2@rGO anode in ether‐based electrolyte

AbstractTo unveil the charge storage mechanisms and interface properties of electrode materials is very challenging for Na‐ion storage. In this work, we report that the novel layered perovskite Bi2TiO4F2@reduced graphene oxides (BTOF@rGO) serves as a promising anode for Na‐ion storage in an ether‐based electrolyte, which exhibits much better electrochemical performance than in an ester‐based electrolyte. Interestingly, BTOF@rGO possesses a prominent specific capacity of 458.3–102 mAh g−1/0.02–1 A g−1 and a high initial coulombic efficiency (ICE) of 70.3%. Cross‐sectional morphology and depth profile surface chemistry indicate not only a denser reactive interfacial layer but also a superior solid electrolyte interface film containing a higher proportion of inorganic components, which accelerates Na+ migration and is an essential factor for the improvement of ICE and other electrochemical properties. Electrochemical tests and ex situ measurements demonstrate the triple hybridization Na‐ion storage mechanism of conversion, alloying, and intercalation for BTOF@rGO in the ether‐based electrolyte. Furthermore, the Na‐ion batteries assembled with the BTOF@rGO anode and the commercial Na3V2(PO4)2F3@C cathode exhibit remarkable energy densities and power densities. Overall, the work shows deep insights on developing advanced electrode materials for efficient Na‐ion storage.

Reactive Solid Polymer Layer: From a Single Fluoropolymer to Divergent Fluorinated Interface

AbstractControlling the structure and chemistry of solid electrolyte interphase (SEI) underpins the stability of electrolyte‐electrode interface, and is crucial for advancing rechargeable lithium metal batteries (LMBs). Here, we utilized photo‐controlled copolymerization to achieve the on‐demand synthesis of fluorosulfonyl fluoropolymers as unprecedented artificial SEI layers on Li metal anodes. This work not only enables instant formation of a hybrid polymer‐inorganic interphase that consists of a polymer‐enriched top layer and a LiF‐fortified bottom layer, originating from a single polymeric component, but also imparts various desirable physical properties (e.g., good mechanical strength and flexibility, high ion conductivity, low overpotential) to SEI via a single‐to‐divergent strategy. Model reactions and structural characterizations supported the formation of a divergent fluorinated interphase, which furnished prolonged stabilization of Li deposition, high coulombic efficiency and improved cycling behavior in electrochemical experiments. This work highlights the great potential of exploring reactive polymers as versatile coatings to stabilize Li metal anodes, providing a promising avenue to solve electrode‐electrolyte interfacial problems for LMBs.

A simple predictive three-step chemical model for gaseous stoichiometric hydrogen–oxygen detonation quenching

Two types of three-step chain-branching kinetics for gaseous hydrogen–oxygen detonation quenching are proposed. The reaction rates dependency on density and pressure, as well as the change in molecular weight are included and fitted to results of detailed chemistry not only along the Hugoniot curve but also behind transverse waves. The trend of induction and reaction times and reduced activation energy of zero-dimensional constant pressure combustion process as well as the induction, reaction lengths, and peak thermicity of the ZND model are focused on in the calibration procedure. One model (3SM-I) is designed to model the ideal detonation whereas the other (3SM-N) focuses on the Dn−κ curve during calibration, i.e. the detonation velocity-mean front curvature curves, aiming to capture the non-idealities. The predictive ability using the proposed models is evaluated in a detonation transmission configuration, a layer of ▪ mixture being confined by N2, in determining the critical height, reactive layer height at which detonation transmission is not possible. Both approaches get closer to the critical height from detailed chemistry. With the present set of model parameters, 3SM-I is better than 3SM-N for prediction of critical height. Moreover, borrowing analytical ignition criteria and wave hierarchy approach, the comparison of various chemical models that are able to recover the critical height suggests that the slope of the Dn−κ curve, linked with the chemical response to losses, is the first key parameter for the critical height determination. In addition, the dynamics of the extinction near criticality such as appearance of transverse detonation and quenching distance from 3SM-I are in very good agreement with that of detailed chemistry due to better estimation of the chemical features along the Hugoniot curve and behind transverse waves. The present study provides a guideline to get simplified chemical models from detailed chemistry for predictive simulations.Novelty and significance statementThe novelty of research is two-fold. The first is to provide general guideline to get simplified models from detailed chemistry for the simulation of detonation extinction with improved predictive ability. The tested configuration was that of a stoichiometric hydrogen–oxygen mixture semi-confined by nitrogen. The evolution of the induction, reaction times, and the maximum thermicity were used as fitting targets for our 3-step model. Furthermore, they were evaluated not only at the post-shock states along the Hugoniot curve, but also behind the transverse waves, keystones of the cellular structure. Second, borrowing analytical ignition criteria and wave hierarchy approach, the comparison of different chemical models that were able to recover the critical height suggested that the slope of the normal velocity–curvature curve was the first key parameter for the critical height determination. Moreover, the dynamics of extinction near criticality, and quenching distance depended on the reaction rate dependency on density and pressure.

Dissolution behavior of hematite in H2SO4 solution: A kinetic analysis and its importance on the zinc hydrometallurgical hematite process

Here, the effect of H2SO4 concentration, temperature, liquid to solid ratio and particle size on the dissolution behavior of industrial hematite in H2SO4 solution. Among them, temperature and H2SO4 concentration have significant effects on the dissolution efficiency of Fe from industrial hematite. Below 363.15 K, the dissolution efficiency of Fe increases with the increase of temperature, but the opposite is true above 363.15 K. Increase H2SO4 concentration to promote the dissolution of industrial hematite. Liquid-solid ratio and particle size had little effect on the Fe concentration after dissolving at 180 min, but it has a significant influence on the Fe dissolution efficiency. The Fe dissolution efficiency of hematite with large particle size is significantly higher than that with small. Shrinking core model with inert reactant layer was employed to describe the dissolving kinetics of industrial hematite in H2SO4 solution. In the temperature range of 303.15 − 343.15 K, the interfacial chemical reaction control is the rate-limiting step. Apparent activation energy (Ea) is 48.1 kJ·mol−1. Based on this, four methods were recommended to prevent the re-dissolution of hematite in industrial practice: (1) increasing the reaction temperature, (2) extending the residence time of hematite in high temperature autoclave, (3) reducing the acidity of the slurry in autoclave though add neutralizer, (4) separating immediately hematite from slurry discharged from the autoclave. This work is of great practical value in terms of iron removal and recycle from the ZnSO4 solution though the hematite process with efficient, clean and low temperature at 423.15 K.

PA/APVC nanofiltration membrane from reactive positively charged substrate membrane

Efficient Li+ and Mg2+ from natural seawater and salt lakes using nanofiltration is essential for efficient extraction of lithium resources and to address the global energy shortage. The combination of size sieving and the Donnan effect is crucial for optimal selectivity. We proposed a positively charged reactive support layer to design dual positively charged layer to enhance the magnesium-lithium separation. The positively charged support layer was prepared by ammoniating the PVC membrane with PEI, and then reacted with TMC to successfully prepare a dual positively charged layer PA/APVC nanofiltration membrane with high Li+/Mg2+ selectivity. The reactive support layer not only established a covalent bond connection with the PA layer, which increased the stability of the active layer, but also showed a positive charge (23.59 mV at pH=7) after ammonization, which further enhanced the Mg2+ repulsion from 82.57 % to 98.56 %. Furthermore, the highest separation factor achieved was 23.34 when a mixed solution containing Mg2+ and Li+ in a mass ratio of 50:1 was utilized, which was 13.48 times that of commercial nanofiltration membranes. The utilization of a reactive substrate membrane in the fabrication process of the PA/APVC membrane offers innovative prospects for future investigations on magnesium-lithium separation, contributing to the advancement of nanofiltration membranes.

Synaptic plasticity and associative learning in IGZO-based synaptic transistor

The increasing demand for efficient data access in high-performance computing systems has emphasized the limitations of the traditional von Neumann architecture, particularly due to the von Neumann bottleneck. This bottleneck arises from the significant power and time consumption required for data transfer between the central processing units and memory, impeding overall system efficiency. Neuromorphic computing offers a promising alternative. Neuromorphic systems emulate biological neurons and synapses, enabling parallel data processing and potentially overcoming the limitations of traditional computing architectures. This study focuses on synaptic transistors with In–Ga–Zn-O (IGZO) channels and TaOx charge trapping layers (Ox-CTL) to enhance neuromorphic computing capabilities. The devices were fabricated using reactive sputtering and atomic layer deposition, followed by comprehensive structural and compositional analyses. Experimental results demonstrated significant hysteresis, high on/off ratios, and multibit conductance states, suggestive of effective charge trapping and detrapping mechanisms. Evaluation through potentiation, depression, and excitatory postsynaptic current (EPSC) measurements, along with simulations using the Modified National Institute of Standards and Technology (MNIST) database, revealed improved pattern recognition accuracy. Additionally, associative learning experiments modeled after Pavlov’s dog conditioning emphasized the device's capability for both long- and short-term memory retention. These findings suggest that IGZO-based synaptic transistors are promising candidates for next-generation neuromorphic computing systems, offering enhanced data processing efficiency and adaptability.

Performance evaluation of GaN etching using Cl2-based plasma with bias pulsing

Reducing plasma-induced damage (PID) is one of the most challenging goals for the fabrication of GaN-based MOS-HEMT. In this paper, we propose a performance evaluation of a Cl2-based etching chemistry using bias pulsing mode for GaN applications. The plasma-induced damage using bias pulsing has been compared to conventional reactive ion etching (RIE) and atomic layer etching (ALE) processes using sheet resistance (Rsheet) measurements. This pulsing mode showed low plasma-induced damage, similar to ALE. In addition, it keeps an acceptable GaN etching rate, showing that pulsing mode has potential for industrial applications.

Effect of Ti content on microstructure and properties of Cu/AgCuTi/Al2O3 brazed joints

In this study, four groups of Ag-Cu-Ti brazing powder with different Ti contents of 2 wt%, 3 wt%, 3.75 wt% and 4 wt% were prepared by vacuum atomization, and then modulated into brazing pastes. Brazing between oxygen-free copper and alumina ceramics with the brazing pastes and the wettability experiments of the brazing pastes on alumina were done by vacuum brazing process at 880℃ for 30 min. Microstructures and wettability of both the braze alloy and joints were analyzed by scanning electron microscope, energy dispersive X-ray spectrometer and transmission electron microscope, and shear strength of the joints was tested by self-designed fixture. Based on thermodynamic calculation and kinetic analysis, the relationship between the products of the reactive layer and the change of Ti content was plotted to explore the reaction and wetting mechanism of AgCuTi braze alloy on alumina ceramics. The results show that the content of Ti in AgCuTi braze alloy is the main factor affecting the brazing performance and wettability of the braze alloy by affecting the products of AgCuTi/Al2O3 reaction layer. The reaction layer consists of TiO when the Ti content is 2 wt%, the reaction layer comprises of TiO and Ti3Cu3O when the Ti content is 3 wt%, the reaction layer is made up of Ti3O2 and Ti3Cu3O when the Ti content is 3.75 wt%, and the reaction layer consists entirely of Ti3Cu3O when the Ti content is 4.6 wt%. With the increase of the Ti content within the range of 2–4.6 wt%, the wettability of the braze alloy on the alumina ceramics improved, and the shear strength of the Cu/AgCuTi/Al2O3 joints increased.

Study on the microstructure and mechanical properties of W-wire/TiBe, ZrBe, and ZrTiBe alloy composites

The microstructure and mechanical performance of W wire/Ti70Be30, Zr65Be35, and Zr37.5Ti26Be36.5 alloy composites were investigated in this study using X-ray diffractometer, scanning electron microscopy, and mechanical universal testing machine. These composites were prepared through the melt impregnation method under optimized processing conditions. The results show that the compressive strength of the three composites is all above 2600 MPa. The Ti70Be30-W composites diffuse violently at the interface, the W-Ti phase is formed at the interface, and the cracks of the composites under the action of applied load show a stepped pattern. The Zr65Be35-W composite reacts violently at the interface, resulting in a W2Zr interfacial product, which adheres to the surface of the W filament and presents a continuous interfacial reaction layer. When subjected to external load, the crack will expand rapidly along the interfacial reactive layer. The addition of Ti in Zr37.5Ti26Be36.5-W composites effectively inhibited the W-Zr reaction, the interface reactant W2Zr disappeared, and the W-Ti interface product presented a discontinuous interfacial reaction layer on the surface of the W filament, and the material split under the action of external load, and the crack showed step-like propagation.

Synergetic regulation of SEI mechanics and crystallographic orientation for stable lithium metal pouch cells

The advancement of Li-metal batteries is significantly impeded by the presence of unstable solid electrolyte interphase and Li dendrites upon cycling. Herein, we present an innovative approach to address these issues through the synergetic regulation of solid electrolyte interphase mechanics and Li crystallography using yttrium fluoride/polymethyl methacrylate composite layer. Specifically, we demonstrate the in-situ generation of Y-doped lithium metal through the reaction of composite layer with Li metal, which reduces the surface energy of the (200) plane, and tunes the preferential crystallographic orientation to (200) plane from conventional (110) plane during Li plating. These changes effectively passivate Li metal, thereby significantly reducing undesired side reactions between Li and electrolytes by 4 times. Meanwhile, the composite layer with suitable modulus (~1.02 GPa) can enhance mechanical stability and maintain structural stability of SEI. Consequently, a 4.2 Ah pouch cell with high energy density of 468 Wh kg−1 and remarkable capacity stability of 0.08% decay/cycle is demonstrated under harsh condition, such as high-areal-capacity cathode (6 mAh cm−2), lean electrolyte (1.98 g Ah−1), and high current density (3 mA cm−2). Our findings highlight the potential of reactive composite layer as a promising strategy for the development of stable Li-metal batteries.

The asymptotic solution of near-limit chain-branching premixed flames with the Zel’dovich–Liñán two-step mechanism in the linear and fast recombination regime

Near-limit characteristics of chain-branching premixed flames is investigated numerically and asymptotically by employing the Zel’dovich–Liñán two-step mechanism with linear and (sufficiently) fast recombination, for which both chain-branching and -recombination steps take place in a thin reactive layer of O(β−1), with β being the chain-branching Zel’dovich number. The numerical and asymptotic results reveal that the rate-ratio eigenvalue r between the chain branching and recombination steps approaches a minimum critical value of rmin→e as the chain-recombination step becomes infinitely fast. The existence of the finite asymptotic value of r=e indicates that no steadily propagating flame solution can be found for fuel concentrations lower than its critical value, corresponding to the criticality of r=e, thereby explaining the (lean) flammability limit. This intrinsic flammability characteristics with linear recombination is the most outstanding contrast to the quadratic recombination counterpart, for which flammability is achieved only with external heat loss added to the model.Novelty and significance statementNear-limit combustion characteristics of chain-branching flames is investigated numerically and asymptotically by employing the Zel’dovich–Linan two-step chemical kinetics with linear and fast recombination. This work demonstrates that the rate-ratio eigenvalue between the chain-branching and -recombination steps asymptotically approaches a critical minimum value, corresponding to the flammability limit. The existence of flammability limit with the linear recombination is found to be the most significant contrast to the quadratic recombination model, which is incapable of predicting flammability limit. By this study, a formal asymptotic procedure, by which the crossover temperature and lean flammability limit condition can be determined without assuming a steady-state approximation of intermediate species, is established and can be applied to analyze flame structures with multi-step reduced mechanisms.

Medium-Entropy Monosilicates Deliver High Corrosion Resistance to Calcium-Magnesium Aluminosilicate Molten Salt.

For decreasing the global cost of corrosion, it is essential to understand the intricate mechanisms of corrosion and enhance the corrosion resistance of materials. However, the ambiguity surrounding the dominant mechanism of calcium-magnesium aluminosilicate (CMAS) molten salt corrosion in extreme environments hinders the mix-and-matching of the key rare earth elements for increasing the resistance of monosilicates against corrosion of CMAS. Herein, an approach based on correlated electron microscopy techniques combined with density functional theory calculations is presented to elucidate the complex interplay of competing mechanisms that control the corrosion of CMAS of monosilicates. These findings reveal a competition between thermodynamics and kinetics that relies on the temperatures and corrosion processes. Innovative medium-entropy monosilicates with exceptional corrosion resistance even at 1500°C are developed. This is achieved by precisely modulating the radii of rare earth ions in monosilicates to strike a delicate balance between the competition in thermodynamics and kinetics. After 50 and 100h of corrosion, the thinnest reactive layers are measured to be only 28.8 and 35.4µm, respectively.

Atomic Layer Deposition Films for Resistive Random‐Access Memories

AbstractResistive random‐access memory (RRAM) stands out as a promising memory technology due to its ease of operation, high speed, affordability, exceptional stability, and potential to enable smaller memory devices with sizes under 10 nm. This has drawn significant attention, with atomic layer deposition (ALD) emerging as an ideal technology to tackle the challenges of nanoscale fabrication in the micro‐ and nanomanufacturing industry. ALD offers technological advantages such as functional multiple‐layer stacking, doping capabilities, and incorporating oxygen reservoirs or reactive layers. These factors contribute to achieving more intriguing, stable, and reliable nonvolatile resistance switching behaviors in RRAM. Specifically, ALD greatly benefits RRAM, that relies on the valence change mechanism, where high‐k transition metal oxides are commonly used as switching materials, and precise control over oxygen vacancies is achievable. This review provides a comprehensive overview of ALD films used in RRAM, delves into resistive switching properties and microscopic mechanisms in binary and ternary oxides and nitrides, and explores the impact of ALD‐prepared electrodes. Furthermore, the current status and future prospects of ALD‐based RRAM are highlighted, which is poised to catalyze further advancements in the fields of information storage and neural networks.

All‐Printed Electrically Driven Lighting via Electrochemiluminescence

AbstractElectrochemiluminescence (ECL) has attracted significant attention as a promising light‐emitting technology owing to its simple configuration and solution processability. ECL has wide applications in biological and chemical sensors, lighting, and displays. ECL lighting devices are fabricated as sandwiched structures with a transparent electrode on top, which limits their widespread adoption. Intricate structures with high precision and customizable designs can be directly fabricated using 3D printing. However, 3D printing of ECL devices is challenging because of poor printability and structural integrity of ECL luminophore inks. Here, all‐printed electrically driven lighting is demonstrated using the direct ink writing method. The ECL reactive layer and electrodes are directly printed using a side‐by‐side electrode configuration. A 3D printable ECL ink is developed by incorporating silica nanoparticles as rheological modifiers to realize well‐defined patterns with high structural integrity. Graphene is introduced on Ag multilayer electrodes to embrace both the electrical conductivity and electrochemical stability for efficient ECL operation. This all‐printing approach allows the fabrication of ECL devices with complex designs, such as combs and spirals. Moreover, it facilitates seamless printing on various substrate materials, making this technology an asset in the fields of biology, chemistry, and electronics.

Prioritization of control measures in leakage scenario using Hendershot theory and FBWM-TOPSIS.

Currently, there is increasing concern about the safety and leakage of process industries. Therefore, the present study aims to prioritize control measures before and after the leakage scenario by using the Hendershot theory and MCDM techniques. In this study, two proactive and reactive layers were selected before and after leakage of tanks, respectively. Then, criteria and alternatives were selected to perform fuzzy TOPSIS (FTOPSIS) and find the best alternative based on the literature review and Hendershot approach. The linear model of the fuzzy Best-Worst method (FBWM) was constructed and resolved using Lingo 17 software. Subsequently, criteria were assigned weights based on thorough calculations of the inconsistency rate. The weight of study experts was equal to 0.25. The results of FBWM showed that the reliability index with a weight of 0.3727 was ranked first and the inconsistency rate ([Formula: see text]) was calculated to be equal to 0.040. Inherent Safety Design (ISD) (0.899) and passive safety (0.767) also ranked first before and after tank leaks, respectively. Using the FBWM method leads to fewer pairwise comparisons and at the same time more stability. Although ISD and passive strategies are more valid and strict, elements of all strategies are necessary for a comprehensive process safety management program.

Cu metallization of Al2O3 ceramics via CuO reduction: Role of SiO2 additive and sintering atmosphere

A Cu-coated Al2O3 substrates which can be used for power modules are prepared via sintering and reduction of CuO–SiO2 film onto the surface of Al2O3 ceramic without precious metal brazing filler or high-vacuum equipment. This method has a significant cost advantage over the existing technology. Effects of oxygen partial pressure from sintering atmosphere and SiO2 content on microstructure and mechanical properties of Cu/Al2O3 interface are systematically investigated. Phase compositions and morphologies of sintered Cu2O layer, reduced Cu layer and reactive layer are characterized via X-ray diffraction and scanning electron microscopy. In addition, physicochemical changes within CuO–SiO2 during sintering are characterized by thermogravimetry-differential scanning calorimeter. It is found that oxygen and SiO2 can promote the generation of Cu2O–CuO–SiO2 eutectic phase with low melting point upon sintering, which increases the thickness of reaction layer and the densification of Cu layer. The shear strength between the Cu layer and the Al2O3 substrate is enhanced with the increase in Cu layer densification degree, while varying in irregular manner with the thickness of reaction layer. In particular, the highest shear strength of 62.70 MPa is obtained at oxygen partial pressure of 0.02 atm and SiO2 content of 1.5 wt%.

Unveiling the Electro‐Chemo‐Mechanical Failure Mechanism of Sodium Metal Anodes in Sodium–Oxygen Batteries by Synchrotron X‐Ray Computed Tomography

AbstractRechargeable sodium–oxygen batteries (NaOBs) are receiving extensive research interests because of their advantages such as ultrahigh energy density and cost efficiency. However, the severe failure of Na metal anodes has impeded the commercial development of NaOBs. Herein, combining in situ synchrotron X‐ray computed tomography (SXCT) and other complementary characterizations, a novel electro‐chemo‐mechanical failure mechanism of sodium metal anode in NaOBs is elucidated. It is visually showcased that the Na metal anodes involve a three‐stage decay evolution of a porous Na reactive interphase layer (NRIL): from the initially dot‐shaped voids evolved into the spindle‐shaped voids and the eventually‐developed ruptured cracks. The initiation of this three‐stage evolution begins with chemical‐resting and is exacerbated by further electrochemical cycling. From corrosion science and fracture mechanics, theoretical simulations suggest that the evolution of porous NRIL is driven by the concentrated stress at crack tips. The findings illustrate the importance of preventing electro‐chemo‐mechanical degradation of Na anodes in practically rechargeable NaOBs.

Remote epitaxy-based atmospherically stable hybrid graphene template for fast and versatile transfer of complex ferroelectric oxides onto Si

Heterogenous integration of complex epitaxial oxides onto Si and other target substrates is recently gaining traction. One of the popular methods involves growing a water-soluble and highly reactive sacrificial buffer layer, such as Sr3Al2O6 (SAO), at the interface and a functional oxide on top of this. To improve the versatility of layer transfer techniques, it is desired to utilize stable (less reactive) sacrificial layers without compromising on the transfer rates. In this study, we utilized a combination of chemical vapor deposited (CVD) graphene as a 2D material at the interface and pulsed laser deposited (PLD) water-soluble SrVO3 (SVO) as a sacrificial buffer layer. We then exploit the well-known enhancement of liquid diffusivities by monolayer graphene to enhance the dissolution rate of SVO over ten times without compromising its atmospheric stability. We demonstrate the versatility of our hybrid- graphene-SVO- template by growing ferroelectric BaTiO3 (BTO) via PLD and Pb(Zr, Ti)O3 (PZT) via Chemical Solution Deposition (CSD) technique and transferring them onto the target substrates and establishing their ferroelectric properties. Our hybrid templates allow for the realization of the potential of complex oxides in a plethora of device applications for MEMS, electro-optics, and flexible electronics.