Formation Of Interlayer Research Articles

Performance and stability enhancement of perovskite photodetectors by additive and interface engineering using a dual-functional PPS zwitterion.

Hybrid organic-inorganic metal halide perovskites (HOIPs) have gained significant research interest due to their tunable optoelectronic properties and ease of fabrication. Enhancing the stability and efficiency of perovskite materials can be achieved through the passivation of defective surfaces and the improvement of interfacial properties. In this study, we introduce a zwitterionic compound, PPS (3-(1-pyridinio)-1-propanesulfonate), as a bifunctional material that serves as an additive and an interlayer. Incorporating PPS into the perovskite film effectively reduces both positively and negatively charged defects, leading to improved surface morphology and a reduction in undesired charge carrier recombination. Additionally, the formation of a PPS interlayer on SnO2 improves the SnO2/perovskite interfacial characteristics, thereby enhancing charge carrier extraction. As a result, the photodetector exhibits a low dark current of 6.05 × 10-11 A, an excellent responsivity of 5.93 A W-1, a detectivity of 1.51 × 1013 J, and an on/off ratio of 1.2 × 104 under open-air conditions. Moreover, the device demonstrates outstanding stability, retaining 80% of its original responsivity in an ambient environment. This work highlights the great potential of dual-functional materials for defect passivation in future optoelectronic devices, emphasizing the importance of surface modification and interface engineering for improved performance and stability.

Elucidating the effect of Ag interlayer formation on the intrinsic mechanical properties of free-standing ITO/Ag/ITO thin films

The impact of Ag interlayer formation governing the intrinsic mechanical behavior of ITO/Ag/ITO thin films is proposed, which can fundamentally contribute to the robust design of advanced flexible electronics.

Effect of surface macroroughness on the microstructure and sliding wear properties of Al2O3 + 13 wt.% TiO2 thick coatings

ABSTRACT
 
 Two macro-roughness patterns namely spiral grooving and diamond knurling were performed on an AISI/SAE 1045 cylindrical steel bar. Al2O3 + 13 wt.-% TiO2 powder was deposited by utilizing a multi-pass torch. Microstructure, microhardness and wear resistance were analyzed. The presence of both γ-Al2O3 and α-Al2O3 throughout the coating was promoted by partially melted and un-melted particles; however, the formation of interlayers of hard α-Al2O3 was influenced by the re-heating during the multi-pass torch causing transformation from γ-Al2O3→α-Al2O3. Knurling pattern specimens contained less defects owe to a suitable splat accommodation thus strengthening the inter-splat anchorage. The improved sliding wear resistance was influenced by both the combination of γ-Al2O3 (toughness) and α-Al2O3 (hardness) phases and, predominantly by the reduced porosity and micro-cracks in specimens with the knurling pattern.

Porous silicon covalently-grafted with chloro-styrenic carbons for fast Li+ diffusion and durable lithium-storage capability

Silicon-based anode materials have critical issues such as drastic volume changes, huge stress generation, and the thickening of solid‒electrolyte interphase layer. Thus, a new strategy for improving silicon interface is necessary for significantly enhanced Li+ ion transportation and structural stability during prolonged cycling, while simultaneously reducing severe side reactions. Herein, we prepared porous silicon particles covalently linked with styrene-based polymers (polystyrene (PS) and poly(4-chlorostyrene) (PCS)) via a facile non-atmospheric thermolytic process at a low-temperature (≤400 °C), in which the decomposed styrenic carbon fragments are covalently grafted on the silicon surface via Si–O–C and Si–C species. Notably, PCS-grafted porous silicon exhibited the significantly enhanced electrochemical performance (i.e., a high rate capability of 1270 mAh g−1 at 20 A g−1, 90.7% of initial capacity at 4 A g−1, and a reversible capacity of 1725 mAh g−1 after 200 cycles), because of the dual covalent linkages of Si–C and Si–O–C species in chloro-styrenic carbons that provide durable lithium storage capability and fast Li+ transportation. Specifically, the Si–C linkage enforced the formation of a durable interlayer that protects the Si active material from reactive electrolytes, and the polarized Si–O–C linkage facilitates the rapid transport of Li+ ions.

Two birds with one stone: Simultaneous realization of constructed 3D/2D heterojunction and p-doping of hole transport layer for highly efficient and stable perovskite solar cells

Combined with the superb moisture and thermal stability of two-dimensional (2D) perovskites and the excellent photoelectronic features of three-dimensional (3D) perovskites, building 3D/2D structure has been proved to be an auspicious way to improve both power conversion efficiency (PCE) and durability of perovskite solar cells (PSCs). In this work, cyclohexylammonium bromide (CMABr) as p-dopant is introduced into hole transport layer (HTL) to form 3D/2D heterostructure perovskite bilayer. It is confirmed that the formation of 2D perovskite interlayer comes from the reaction between the excess PbI2 on the surface of 3D perovskite and CMABr on the bottom of HTL, which served as moisture barrier layer to enhance the device stability. The exotic CMA+ and Br− ions could insert the ABX3 perovskite lattice to compensate A-site cation and X-site vacancies, which reduced the undesirable non-radiative recombination centers. Owing to the p-type doping, the more uniform morphology, down-shifted energy levels and improved electrical properties were obtained. Consequently, the CMABr-doped PSCs based on triple-cation (Cs+, MA+ and FA+) perovskite and double-cation (MA+ and FA+) perovskite produce maximum PCEs of 21.78 % and 23.56 %, respectively, as well as remarkable long-term device stability. The results demonstrate a novel pathway to construct 3D/2D stacking structure for highly efficient PSCs with decent stability.

Diazotization Grafting Phenol for Improving the Electrochemical Performance of Graphite Anode

Capacity fading resulting from graphite exfoliation is a thorny problem for real application of the graphite anodes in lithium-ion batteries. In this paper, we report on diazotization grafting phenol for graphite flakes to settle this issue, using 4-aminophenol and tert-butyl nitrite as the diazonium reagents. Diazotization grafting phenol enables expansion of graphite interlayer spacing and formation of surface protective layer, yielding modified graphite anodes with improved electrode kinetics, and significantly improved cycling stability. Also, the phenol modifier contributes additional specific capacity to the anode through reversible redox reaction of phenol hydroxyls with Li+ ions. The modified graphite anode with mole percent of 4-aminophenol to graphite being 5% retains a discharge specific capacity of 361 mA h g‒1 after 300 cycles at 1C, presenting capacity retention of 90.5% relative to the initial cycle, much higher than that of 156 mA h g‒1 and 54.2% for pristine graphite.

New Perylene Diimide Ink for Interlayer Formation in Air-Processed Conventional Organic Photovoltaic Devices.

Roll-to-roll coating of conventional organic photovoltaic architectures in air necessitates low work function, electron-harvesting interlayers as the top interface, termed cathode interlayers. Traditional materials based on metal oxides are often not compatible with coating in air and/or green solvents, require thermal annealing, and are limited in feasibility due to interactions with underlying layers. Alternatively, perylene diimide materials offer easily tunable redox properties, are amenable to air coating in green solvents, and are considered champion organic-based cathode interlayers. However, underlying mechanisms of the extraction of photogenerated electrons are less well understood. Herein, we demonstrate the utilization of two N-annulated perylene diimide materials, namely, PDIN-H and CN-PDIN-H, in air-processed conventional organic photovoltaic devices, using the now standard PM6:Y6 photoactive layer. The processing ink formulation using cesium carbonate as a processing agent to solubilize the perylene diimides in suitable green solvents (1-propanol and ethyl acetate) for uniform film formation using spin or slot-die coating on top of the photoactive layer is critical. Cesium carbonate remains in the film, creating hybrid organic/metal salt cathode interlayers. Best organic photovoltaic devices have power conversion efficiencies of 13.2% with a spin-coated interlayer and 13.1% with a slot-die-coated interlayer, superior to control devices using the classic conjugated polyelectrolyte PFN-Br as an interlayer (ca. 12.8%). The cathode interlayers were found to be semi-insulating in nature, and the device performance improvements were attributed to beneficial interfacial effects and electron tunneling through sufficiently thin layers. The efficiencies beyond 13% achieved in air-processed organic photovoltaic devices utilizing slot-die-coated cathode interlayers are among the highest reported so far, opening new opportunities for the fabrication of large-area solar cell modules.

Evaluation and Analysis of Engineering Geological Features Affecting Fracturing Effect in Block S


 Reservoir evaluation and classification is an important content in oil and natural gas exploration and development. Reasonable and scientific evaluation of reservoirs has important guiding significance for the discovery of "sweet spots" in the later stage, the optimization of favorable areas and the optimization of fracturing stimulation measures in the later stage. , this paper evaluates and analyzes 6 engineering geological factors of reservoir rock compressibility, horizontal difference stress coefficient, reservoir interlayer stress difference, rupture pressure, closure stress and formation pressure coefficient in block S, and combines with the analysis of unimpeded flow after compression to find The favorable range value of each factor provides an important basis for the subsequent evaluation and analysis of other fracturing wells and the recommendation of fracturing process countermeasures. Based on the engineering geological factors that affect the fracturing effect, a new method for evaluating the geological quality of fracturing engineering is established, and the reservoirs with the comprehensive coefficient of fracturing engineering geological quality between 0.53 and 1 are regarded as high-quality A-level reservoirs. , the reservoirs with the comprehensive coefficient of fracturing engineering geological quality between 0.2 and 0.53 are regarded as the B-level general quality reservoirs, and the reservoirs with the comprehensive coefficient of fracturing engineering geological quality between 0 and 0.2 are regarded as the C-level poor quality reservoirs, which are selected for fracturing selection. Well selection provides an important basis.

Oxidation Resistance of γ-TiAl Based Alloys Modified by C, Si and Y2O3 Microdopants

This work aimed to study the oxidation resistance of γ-TiAl based alloy, doped with small concentrations of carbon, silicon, and yttrium oxide in air at 800 and 1100 °C for 30 h. The TNM-B1 alloy samples were produced via high-energy ball milling, self-propagating high-temperature synthesis, and hot isostatic pressing techniques. The microstructure, oxidation kinetics at 800–1100 °C, scale structure, and oxidation mechanism were studied. The oxidation of alloys modified with carbon and silicon at 1100 °C was characterized by the formation of a three-layer coating. The Y2O3 modified alloy performed the greatest oxidation resistance at 1100 °C and promoted the formation of a dense Al2O3 interlayer.

Interface engineering for a VOx based memristor with an ultralow switching voltage and logic functions

A Ti/VOx/ITO memristor prepared at room temperature presents low switching voltages (set/reset voltages ~ −6 mV/190 mV) as well as good resistive switching characteristics including acceptable ON/OFF ratio (~ 10) and long data retention (>104 s). Such ultralow switching voltages mainly result from appropriate interface engineering combined with rational material design. Due to Ti’s high oxygen-gettering capability, its contact with VOx leads to formation of a TiOx interlayer with numerous oxygen vacancies (VO2+) near the interface even at room temperature. This interfacial VO2+ facilitates oxygen ions (O2-) migration by enlarging the available free space and weakening the local oxygen-cation bonds, thus resulting in the low switching voltages. Moreover, the graded O2- distribution in the TiOx interlayer induces a built-in electric field (Ebuilt-in), which has the same direction to the external electric field generated by the set voltage. This Ebuilt-in accelerates the O2- migration and thus leads to the ultralow set voltage. The resistive switching mechanism is revealed to be based on formation and collapse of the Schottky barrier caused by the O2- drift in the TiOx interlayer. The Boolean logic functions including ‘NOT’, ‘AND’, ‘OR’, ‘NAND’ and ‘NOR’ are demoed by using a single memristor, showing a great potential for in-memory computing.

Universal Dynamic Liquid Interface for Healing Perovskite Solar Cells.

Healing charge-selective contact interfaces in perovskite solar cells (PSCs) highly determines the power conversion efficiency (PCE) and stability. However, the state-of-the-art strategies are often static by one-off formation of a functional interlayer, which delivers fixed interfacial properties during the subsequent operation. As a result, defects formed in-service will gradually deteriorate the photovoltaic performances. Herein, a dynamic healing interface (DHI) is presented by incorporating a low-melting-point small molecule onto perovskite film surface for highly efficient and stable PSCs. Arising from the reduced non-radiative recombination, the DHI boosts the PCE to 12.05% for an all-inorganic CsPbIBr2 solar cell and 14.14% for a CsPbI2 Br cell, as well as 23.37% for an FA0.92 MA0.08 PbI3 (FA = formamidinium, MA = methylammonium) cell. The solid-to-liquid phase conversion of DHI at elevated temperature causes a longitudinal infiltration into the bulk perovskite film to maximize the charge extraction, passivate defects at grain boundaries, and suppress ion migration. Furthermore, the stability is remarkably enhanced under air, heat, and persistent light-irradiation conditions, paving a universal strategy for advanced perovskite-based optoelectronics.

The Role of SnF2 Additive on Interface Formation in All Lead‐Free FASnI3 Perovskite Solar Cells

AbstractTin‐based perovskites are promising alternative absorber materials for lead‐free perovskite solar cells but need strategies to avoid fast tin (Sn) oxidation. Generally, this reaction can be slowed down by the addition of tin fluoride (SnF2) to the perovskite precursor solution, which also improves the perovskite layer morphology. Here, this work analyzes the spatial distribution of the additive within formamidinium tin triiodide (FASnI3) films deposited on top of poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) hole transporting layers. Employing time‐of‐flight secondary ion mass spectrometry and a combination of hard and soft X‐ray photoelectron spectroscopy, it is found that SnF2 preferably accumulates at the PEDOT:PSS/perovskite interface, accompanied by the formation of an ultrathin SnS interlayer with an effective thickness of ≈1.2 nm.

Interfacial Modulated Lattice-Polarity-Controlled Epitaxy of III-Nitride Heterostructures on Si(111)

Monolithic integration of wurtzite III-nitrides with nonpolar silicon (Si), the two most-produced semiconductor materials, is essential and critical for a broad range of applications in electronics, optoelectronics, quantum photonics, and renewable energy. To date, however, it has remained challenging to achieve III-nitride heterostructures on Si with controlled lattice-polarity. Herein, we show that such critical challenges of III-nitrides on Si can be fundamentally addressed through a unique interfacial modulated lattice-polarity-controlled epitaxy (IMLPCE). It is discovered that the lattice-polarity of aluminum nitride (AlN) grown on Si(111) is primarily determined by the AlSiN interlayer: N-polar and Al-polar AlN can be achieved by suppressing and promoting the AlSiN interlayer formation, respectively. Furthermore, we develop a unique active-nitrogen-free in situ annealing process to mitigate the AlSiN layer formation at the GaN/AlN interface, which can eliminate the inverted domain formation commonly seen in N-polar GaN on AlN/Si. This study provides an alternative approach for controlling the lattice-polarity of III-nitrides on Si substrates and will enable their seamless integration with the mature Si-based device technology.

Synergistic Effect of Halogen Ions and Shelling Temperature on Anion Exchange Induced Interfacial Restructuring for Highly Efficient Blue Emissive InP/ZnS Quantum Dots.

InP quantum dots (QDs) have attracted much attention owing to their nontoxic properties and shown great potential in optoelectronic applications. Due to the surface defects and lattice mismatch, the interfacial structure of InP/ZnS QDs plays a significant role in their performance. Herein, the formation of In-S and Sx -In-P1-x interlayers through anion exchange at the shell-growth stage is revealed. More importantly, it is proposed that the composition of interface is dependent on the synergistic effect of halogen ions and shelling temperature. High shelling temperature contributes to the optical performance improvement resulting from the formation of interlayers, besides the thicker ZnS shell. Moreover, the effect relates to the halogen ions where I- presents more obvious enhancement than Br- and Cl- , owing to their different ability to coordinate with In dangling bonds, which are inclined to form In-S and Sx -In-P1-x bonds. Further, the anion exchange under I- -rich environment causes a blue-shift of emission wavelength with shelling temperature increasing, unobserved in a Cl- - or Br- -rich environment. It contributes to the preparation of highly efficient blue emissive InP/ZnS QDs with emission wavelength of 473nm, photoluminescence quantum yield of ≈50% and full width at half maximum of 47nm.

Study of LiCoO2/Li7La3Zr2O12:Ta Interface Degradation in All-Solid-State Lithium Batteries.

The garnet-type Li7La3Zr2O12 (LLZO) ceramic solid electrolyte combines high Li-ion conductivity at room temperature with high chemical stability. Several all-solid-state Li batteries featuring the LLZO electrolyte and the LiCoO2 (LCO) or LiCoO2-LLZO composite cathode were demonstrated. However, all batteries exhibit rapid capacity fading during cycling, which is often attributed to the formation of cracks due to volume expansion and the contraction of LCO. Excluding the possibility of mechanical failure due to crack formation between the LiCoO2/LLZO interface, a detailed investigation of the LiCoO2/LLZO interface before and after cycling clearly demonstrated cation diffusion between LiCoO2 and the LLZO. This electrochemically driven cation diffusion during cycling causes the formation of an amorphous secondary phase interlayer with high impedance, leading to the observed capacity fading. Furthermore, thermodynamic analysis using density functional theory confirms the possibility of low- or non-conducting secondary phases forming during cycling and offers an additional explanation for the observed capacity fading. Understanding the presented degradation paves the way to increase the cycling stability of garnet-based all-solid-state Li batteries.

Water-assisted crystallization of amorphous indium zinc oxide films

Transparent conductive materials based on indium oxide remain yet irreplaceable in various optoelectronic applications. Amorphous oxides appear especially attractive for technology as they are isotropic, demonstrate relatively high electron mobility and can be processed at low temperatures. Among them is indium zinc oxide (IZO) with a large zinc content that is crucial for keeping the amorphous state but redundant for the doping. In this work we investigated water-free and water containing IZO films obtained by radio frequency sputtering. The correlation between temperature driven changes of the chemical state, the optical and electrical properties as well as the progression of crystallization was in focus. Such characterization methods as: scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, temperature dependent Hall-effect measurements and others were applied. Temperature dependent electrical properties of amorphous IZO and IZO:H2O films were found to evolve similarly. Based on our experience in In2O3:H2O (In2O3:H or IOH) we proposed an explanation for the changes observed. Water admixture was found to decrease crystallization temperature of IZO significantly from ∼ 550 °C to ∼ 280 °C. Herewith, the presence and concentration of water and/or hydroxyls was found to determine Zn distribution in the film. In particular, Zn enrichment was detected at the film’s surface respective to the high water and/or hydroxyl amount. Raman spectra revealed a two-dimensional crystallization of w-ZnO which precedes regardless water presence an extensive In2O3 crystallization. An abrupt loss of electron mobility as a result of crystallization was attributed to the formation of ZnO interlayer on grain boundaries.

Interfacial modification and performance enhancement of carbon matrix/aluminum composites

Carbon/Aluminum (C/Al) composites are receiving great attentions because they can present both good mechanical and electrical performance while keeping lightweight. However, the non-wettability of carbon and aluminum as well as the avoidable formation of the brittle phase Al4C3 can lead to a weak adhesion interface, limiting the performance improvement of the composites. In this work, an interlayer of silicon carbide and aluminum-silicon alloy the silicon was constructed at the interfaces of carbon matrix and aluminum, in order to resolve the bottleneck problem of composites performance improvement. Results indicated that the wettability of carbon matrix and aluminum melt was significantly improved by the constructed interlayer, and the contact angle decreased from 91° to 41°. Optimized parameters for the formation of moderate interlayer were also systematically examined. The interface of C/Al composites was changed from C/Al4C3/Al to C/SiC/Al-Si, resulting in the improvement of compressive strength, flexural strength and electrical conductivity from 212.75 MPa, 94.95 MPa, 2.25 × 105 S/m to 362.24 MPa, 144.42 MPa, 4.03 × 105 S/m, respectively, far better than the requirement of industrial standard. Mechanisms for the performance enhancement are also discussed.

Impact of interlayer insulator formation methods on HfOx ferroelectricity in the metal–ferroelectric–insulator–semiconductor stack

It has been reported that the HfOx-based metal–ferroelectric–insulator–semiconductor (MFIS) stack is one of the most feasible structures for memory applications in ferroelectric devices. In addition, in MFIS stacks, the formation of a high-quality thin insulator is considered to be a crucial process, because it determines the device performance and reliability. In this study, the effects of different SiO2 thin interfacial layers (ILs) formed by chemical oxidation and atomic layer deposition (ALD) on the ferroelectricity of HfOx were investigated in MFIS stacks. Notably, the IL formation method affected the crystallization temperature of HfOx ferroelectricity. In particular, the chemical oxide IL sample was sufficiently crystallized only at an RTA temperature greater than 800 °C, whereas the ALD oxide IL sample began to undergo a complete ferroelectric phase transition from a low temperature (600 °C). The x-ray analysis verified that the IL formation method affected the initial film state of the HfOx layer by modulating the Hf-O bonding states, resulting in a different temperature dependence for ferroelectricity formation during the subsequent crystallization annealing stage. Consequently, it was confirmed that stable polarization (2Pr > 30 μC/cm2) could be obtained over a wide temperature range (600–800 °C) through IL material engineering; this could facilitate the integration of HfOx-based ferroelectric devices in terms of the heat budget and the application of ferroelectric devices as commercial devices.

Charge Transfer Properties of Heterostructures Formed by Bi2 O2 Se and Transition Metal Dichalcogenide Monolayers.

Atomically thin bismuth oxyselenide (Bi2 O2 Se) exhibits attractive properties for electronic and optoelectronic applications, such as high charge-carrier mobility and good air stability. Recently, the development of Bi2 O2 Se-based heterostructures have attracted enormous interests with promising prospects for diverse device applications. Although the electrical properties of Bi2 O2 Se-based heterostructures have been widely studied, the interlayer charge transfer in these heterostructures remains elusive, despite its importance in harnessing their emergent functionalities. Here, a comprehensive experimental investigation on the interlayer charge transfer properties of two heterostructures formed by Bi2 O2 Se and representative transition metal dichalcogenides (namely, WS2 /Bi2 O2 Se and MoS2 /Bi2 O2 Se) is reported. Kelvin probe force microscopy is used to measure the work functions of the samples, which are further employed to establish type-II band alignment of both heterostructures. Photoluminescence quenching is observed in each heterostructure, suggesting high charge transfer efficiency. Time-resolved and layer-selective pump-probe measurements further prove the ultrafast interlayer charge transfer processes and formation of long-lived interlayer excitons. These results establish the feasibility of integrating 2D Bi2 O2 Se with other 2D semiconductors to fabricate heterostructures with novel charge transfer properties and provide insight for understanding the performance of optoelectronic devices based on such 2D heterostructures.

In Situ X-ray Diffraction of LiCoO2 in Thin-Film Batteries under High-Voltage Charging

LiCoO2 has been used as the cathode material employed in lithium-ion batteries since their development, and efforts to improve its performance are still in progress. For example, complete use of lithium provides a theoretical capacity as high as 274 mAh g–1; however, charge–discharge cycling with such a high capacity leads to rapid degradation. The degradation mechanism has been intensively studied in order to increase the practical capacity. Although phase transitions taking place in high-voltage charging have been considered to affect the cycling performance, side reactions induced by the high-voltage charging always overlap to blur the effects of phase transitions on the electrode properties. This study has unveiled the relation between the phase transition and electrode properties by employing a solid electrolyte that suppresses the side reactions efficiently. Electrochemical impedance spectroscopy combined with in situ X-ray diffraction shows clear correlation between phase transition from O3 to H1–3 and a drastic increase in the electrode resistance. The increasing resistance is attributable to formation of narrow interlayers with a gallery height of 4.2 Å that impede lithium-ion diffusion.