Thin Films Research Articles

Explicit relation between thin film chromatography and column chromatography conditions from statistics and machine learning

Explicit relation between thin film chromatography and column chromatography conditions from statistics and machine learning

Photoelectrochemical and Catalytic Hydrogen Generation from Hydrolysis of NaBH4 using Ruthenium and Platinum Decorated ZnO/TiO2 Heterojunction Thin Film Electrodes

Photoelectrochemical and Catalytic Hydrogen Generation from Hydrolysis of NaBH4 using Ruthenium and Platinum Decorated ZnO/TiO2 Heterojunction Thin Film Electrodes

Phase Coexistence Induced Giant Dielectric Tunability and Electromechanical Response in PbZrO3 Epitaxial Thin Films.

PbZrO3 (PZO) thin films, as a classic antiferroelectric material, have attracted tremendous attention for their excellent dielectric, electromechanical, and thermal switching performances. However, several fundamental questions remain unresolved, particularly the existence of an intermediate phase during the transition from the antiferroelectric (AFE) to ferroelectric (FE) state. Here, a phase coexistence configuration of an orthorhombic AFE phase and a tetragonal-like (T-like) phase is reported in epitaxial antiferroelectric PZO thin films, with thickness ranging from 16 to 110nm. This configuration is evidenced both macroscopically by distinct shoulder-cape-shaped dielectric behavior and microscopically through scanning transmission electron microscopy (STEM) analysis. Remarkably, a 49nm PZO film achieves an ultrahigh dielectric tunability of 90.1%, while a 59nm film exhibits significant electromechanical strain of 0.66%. Microscopically, HAADF-STEM reveals the presence of the intermediate phase with a dipole arrangement of vertically diagonal up-up-down-down pattern, and first-principles calculations further confirm the role of this intermediate phase during AFE-to-FE phase transition, which is responsible for the unusual dielectric peaks of ɛr-E curves. These findings not only enhance the understanding of phase transition in antiferroelectric materials but also exhibit great potential for high-performance tunable and nano-electromechanical device applications.

Confocal Raman Microscopy for Measuring In Situ Temperature-Dependent Structural Changes in Poly(Ethylene Oxide) Thin Films.

Crystallization from the melt is a critical process governing the properties of semi-crystalline polymeric materials. While structural analyses of melting and crystallization transitions in bulk polymers have been widely reported, in contrast, those in thin polymer films on solid supports have been underexplored. Herein, in situ Raman microscopy and self-modeling curve resolution (SMCR) analysis are applied to investigate the temperature-dependent structural changes in poly(ethylene oxide) (PEO) films during melting and crystallization phase transitions. By resolving complex overlapping sets of spectra, SMCR analysis reveals that the thermal transitions of 50 µm thick PEO films comprise two structural phases: an ordered crystalline phase and a disordered amorphous phase. The ordered structure of the crystalline PEO film entirely disappears as the polymer is heated; conversely, the disordered structure of the amorphous PEO film reverts to the ordered structure as the polymer is cooled. Broadening of the Raman bands was observed in PEO films above the melting temperature (67 °C), while sharpening of bands was observed below the crystallization temperature (45 °C). The temperatures at which these spectral changes occurred were in good agreement with differential scanning calorimetry (DSC) measurements, especially during the melting transition. The results illustrate that in situ Raman microscopy coupled with SMCR analysis is a powerful approach for unraveling complex structural changes in thin polymer films during melting and crystallization processes. Furthermore, we show that confocal Raman microscopy opens opportunities to apply the methodology to interrogate the structural features of PEO or other surface-supported polymer films as thin as 2 µm, a thickness regime beyond the reach of conventional thermal analysis techniques.

Boosting Thermal Generation in Cation-Exchanged Transparent MXene Composite Films with Hierarchical Wrinkled Structure.

Efficient thermal generation from solar/electric energy in transparent films remains challenging due to the limited toolbox of high-performance thermal generation materials and methods for microstructure engineering. Here, we proposed a two-step strategy to introduce hierarchical wrinkles to the MXene composite films with high transparency, leading to upgraded photo/electrothermal conversion efficiency. Specifically, the thin film contains protic acid-treated MXene layers assembled with Ag nanowires (H-MXene/Ag NWs). The hydrogen-bonding interaction between MXene and Ag NWs in a MXene-based thin film forms the first-level wrinkles, while the cation-exchanged method is then developed to enhance conductivity and form the second-level wrinkles. The H-MXene/Ag NWs composite transparent film is observed to achieve a surface temperature rise of 40 °C relative to an ambient environment under 1.0 sun illumination and 70 °C at 1 V voltage in the dark, along with notable photo/electrothermal production stability under ambient conditions. Moreover, experimental and theoretical results show that the improved heat production capability is mainly due to low reflectivity led by the wrinkles and high conductivity led by the cation-exchange process. On the basis of the excellent photothermal generation capability of the H-MXene/Ag NWs composite transparent film, we applied it to biomimetic soft robots and flexible wearable devices. This work paves a novel strategy for the generation of thermal production devices that achieve high-performance photo/electroconversion.

Numerical Study on the Mechanism of Gas Explosion Suppression by Different Arrangement Forms of Staggered Cylinders

ABSTRACT In order to study the suppression mechanism of porous media on gas explosion, the gas explosion behavior in a pipeline with one end closed and the other end temporarily closed by a thin film was numerically simulated in this paper, in which the porous media structure was characterized by “pseudo-porous media” composed of staggered cylinders. The RANS method is used to simulate turbulence in numerical calculation, and the coupling effect between turbulence and combustion is described by the reaction progress variable equation. The calculation results show that, compared with porosity, hole spacing is a more critical parameter affecting gas explosion. The function of pores is mainly reflected in the initial stage of explosion flame development, and the function of pore spacing is reflected after the flame reaches the maximum instantaneous displacement velocity. When the Pe number calculated based on local aperture and laminar flame velocity is less than 72, the flame cannot pass through porous media, and the influence of porous media on gas explosion can be shown. When the Pe number is greater than this value, the influence of porous media on gas explosion is not obvious; The hole spacing has a significant effect on the flame shape, bifurcation number, and flame thickness. When the hole spacing is larger, the flame front is more slender and bifurcated, while when the hole spacing is smaller, the flame presents a more blunt shape, and its expansion is delayed to a greater extent. This law provides a strong basis for the optimization of porous media in burner design, especially in adjusting the flame shape and improving combustion efficiency.

A sustainable and green method for controlling acidic corrosion on mild steel using leaves of Araucaria heterophylla

There are several studies that announce the inhibitory behavior of this sort of substance to strengthen the shield of metals, which is one of the positive benefits of green inhibitors. In the current investigation, Araucaria heterophylla studied as a green corrosion inhibitor to avert the mild steel during the acidic cleaning. The examination of this plant’s ability to control corrosion at different concentrations in the acidic solution used certain expert measures. The electrochemical results suggested that Araucaria heterophylla had a stronger inhibitory effect on mild steel protection from corrosion. After 12 h of immersion, 1000 ppm of A. heterophylla extract produced corrosion inhibition efficacy (about 83.94%). According to the polarization outcomes, the mild steel corrosion current density dramatically decreased with the addition of Araucaria heterophylla extract, going from 1.08 μA/cm2 for the sample without inhibitor to 0.17 μA/cm2 for the sample having 1000 ppm inhibitor and according to electrochemical study the inhibition efficiency was found around 83%. Flavonoids were found in the plant’s leaves according to the high-performance thin-layer chromatography profile. The FTIR picks analysis like N–H stretching secondary amine (3337.07 cm−1), CO–O–C–O stretching anhydride (1022.64 cm−1) defined that functional groups and heteroatom were present. By the help of a GC–MS, the suggested inhibitor’s components were identified. Scanning electron microscopy suggests that a thin layer or passive film form on the surface. Quantum chemical calculation also supports the experimental results.

Correction: Effect of Extrapolation Length on Electrical Properties for Ba0.8Sr0.2TiO3 Ferroelectric Thin Films

Correction: Effect of Extrapolation Length on Electrical Properties for Ba0.8Sr0.2TiO3 Ferroelectric Thin Films

SRT3025-loaded cell membrane hybrid liposomes (3025@ML) enhanced anti-tumor activity of Oxaliplatin via inhibiting pyruvate kinase M2 and fatty acid synthase

BackgroundBladder cancer is one of the most common malignancies of the urinary system. Despite significant advances in diagnosis and treatment, the compromised therapeutic effect of chemotherapeutic agents, such as Oxaliplatin (OXA), remains a major clinical challenge. Thus, a combination therapy is required to enhance the OXA’s therapeutic effectiveness and improve patient outcomes.MethodsThe thin film hydration method was used to prepare the liposomes. Drug encapsulation efficiency and loading capacity were determined to investigate the advantages of the SRT3025-loaded cell membrane hybrid liposomes (3025@ML). Bladder cancer cell lines T24 and 5637 were cultured in McCoy’s 5 A and RPMI 1640 medium, respectively. The Cell Counting Kit-8 assay was used to determine the cell viability by treating cells with a medium containing either the vehicle solution (control), the cell membrane hybrid liposomes (ML), 3025@ML, or compound 3 K. The antiproliferative activities were investigated after treating cells with OXA + 3025@ML and compound 3 K + OXA. Cell death and apoptosis were quantified by trypan blue and Annexin V-APC/PI apoptosis assay after treating cells with control, OXA, OXA + 3025@ML, and 3025@ML. Western blot analysis was performed after treating cells with 3025@ML, OXA, 3 K, 3025@ML + OXA, and 3 K + OXA to determine the protein levels of pyruvate kinase M2 (PKM2) and fatty acid synthase (FASN), etc.ResultsThe present study demonstrated that 3025@ML enhances the chemotherapeutic effect of OXA. 3025@ML + OXA treated T24 and 5637 cells showed that combination therapy significantly reduced cell viability and increased cell death rate. Flow cytometry analysis showed that the combination of 3025@ML and OXA significantly increased the percentage of apoptotic cells in T24 cells. 3025@ML and compound 3 K reduced the levels of FASN in T24 and 5637 cells and increased the anti-tumor activity of OXA. Mechanistic studies showed that 3025@ML inhibited the PI3K/AKT/mTOR signaling pathway and reduced the expression of key metabolic regulators PKM2 and FASN. Furthermore, this study demonstrated that targeting lipid metabolism and inhibiting FASN can effectively overcome the compromised therapeutic effect of OXA.ConclusionThe study demonstrated that 3025@ML significantly enhances the anti-tumor activity of OXA. This novel drug delivery system inhibits key metabolic pathways, which increase DNA damage and tumor cell apoptosis. The results indicate that 3025@ML is a promising therapeutic strategy for overcoming OXA’s compromised therapeutic effect and potentially improving cancer treatment outcomes.

Design of an Atomic Layer-Deposited In2O3/Ga2O3 Channel Structure for High-Performance Thin-Film Transistors.

For potential application in advanced memory devices such as dynamic random-access memory (DRAM) or NAND flash, nanolaminated indium oxide (In-O) and gallium oxide (Ga-O) films with five different vertical cation distributions were grown and investigated by using a plasma-enhanced atomic layer deposition (PEALD) process. Specifically, this study provides an in-depth examination of how the control of individual layer thicknesses in the nanolaminated (NL) IGO structure impacts not only the physical and chemical properties of the thin film but also the overall device performance. To eliminate the influence of the cation composition ratio and overall thickness on the IGO thin film, these parameters were held constant across all conditions. Thin-film transistors (TFTs) with a homogeneous In0.72Ga0.29Ox channel layer (referred to as IGO18) exhibited a reasonable field-effect mobility (μFE) of 58.1 cm2/(V s) and ION/OFF ratio of >108. A significant improvement (∼94.1 cm2/(V s)) in μFE was observed for TFTs with an In2O3/Ga2O3 heterojunction stack (referred to as IGO1). Because the channel layers of both devices had an identical average cation composition and physical thickness, the superior performance of the latter can be attributed to the emergence of a quasi-two-dimensional electron gas (2DEG) and the attainment of high-quality crystallinity. This study underscores the criticality of supercycle duty design to prevent cation intermixing, enabling the exploitation of the 2DEG effect in high-performance oxide TFTs for memory device applications.

Selective area molecular beam epitaxy of InSb on InP(111)B: from thin films to quantum nanostructures.

InSb is a material of choice for infrared as well as spintronic devices but its integration on large lattice mismatched semi-insulating III-V substrates has so far altered its exceptional properties. Here, we investigate the direct growth of InSb on InP(111)B substrates with molecular beam epitaxial growth. Despite the lack of a thick metamorphic buffer layer for accommodation, we show that quasi-continuous thin films can be achieved using a very high Sb/In flux ratio. The quality of the films is further studied with Hall measurements on large-scale devices to assess the impact of the InSb surface and InSb/InP interface on the electronic properties. Taking advantage of the optimized growth conditions for the formation of thin films, the selective area molecular beam epitaxial growth of nanostructures is subsequently investigated. Based on cross-sectional transmission electron microscopy and scanning near field optical microscopy in the middle-wave infrared, ultra-thin and very long in-plane InSb nanowires as well as more complex nanostructures such as nano-rings and crosses are achieved with a good structural quality.&#xD.

Quantum control in size selected semiconductor quantum dot thin films

Abstract We introduce a novel technique for coherent control that employs resonant internally generated fields in CdTe quantum dot (QD) thin films at the L-point. The bulk band gap of CdTe at the L-point amounts to 3.6 eV, with the transition marked by strong Coulomb coupling. Third harmonic generation (λ 3 = 343 nm, hν = 3.61 eV) for a fundamental wavelength of λ 1 = 1,030 nm is used to control quantum interference of three-photon resonant paths between the valence and conduction bands. Different thicknesses of the CdTe QDs are used to manipulate the phase relationship between the external fundamental and the internally generated third harmonic, resulting in either suppression or strong enhancement of the resonant third harmonic, while the nonresonant components remain nearly constant. This development could pave the way for new quantum interference–based applications in ultrafast switching of nanophotonic devices.

Surfing the Growth Parameters in the Quest for Low-Power, Forming-Free, and Highly Stable TiOx Memristors for Nanoscale Electronics.

Understanding the resistive switching (RS) behavior of oxide-based memory devices at nanoscale is crucial for advancement of high-integration density in-memory computing platforms. This study explores a comprehensive growth parameter space to address the RS behavior of pulsed-laser-deposited substoichiometric TiO2 (TiOx) thin films in search of tailored nanoscale memristors with low-power consumption and high stability. Conductive-atomic-force-microscopy-based measurements facilitate deciphering the switching behavior at nanoscale, providing a direct avenue to understand the microstructure-property relationships. The present investigation reveals that rutile TiOx in an optimal stoichiometric configuration exhibits superior RS attributes, enabling forming-free, low-power, and highly stable memory functionalities at nanoscale. By contrast, the expected formation of the Magnéli phase within a highly defective as-grown TiOx film hinders the occurrence of switching. Detailed analyses yield a comprehensive parametric phase diagram, providing valuable insights to predict the optimal growth parameters for fabricating on-demand TiOx-based switching devices. As bulk RS attributes do not always translate seamlessly to the nanoscale, present study leads the pathway to develop tailored memristors for nanoscale electronics promoting their integration into ultrahigh-density, low-energy-consuming advanced memory technologies across diverse disciplines including robotics, data storage, and sensing.

Tuning Electrical Conductivity and Ultrafast Optical Nonlinearity of Reduced-GO Films Ablated by Femtosecond Laser Direct Writing

Carbon-based nanomaterials with excellent electrical and optical properties are highly sought after for a plethora of hybrid applications, ranging from advanced sustainable energy storage devices to opto-electronic components. In this contribution, we examine in detail the dependence of electrical conductivity and the ultrafast optical nonlinearity of graphene oxide (GO) films on their degrees of reduction, as well as the link between the two properties. The GO films were first synthesized through the vacuum filtration method and then reduced partially and controllably by way of femtosecond laser direct writing with varying power doses. Subsequently, the four-point probe measurements of the reduced-GO (r-GO) films were demonstrated to exhibit superior resistivity and electrical conductivity compared with the pristine-GO counterpart. It was found that the conductivity of the film increases and then decreases with increasing ablation laser power (P), and GO was completely reduced at P = 100 mW, with a resistivity and electrical conductivity of 1.09 × 10−3 Ω·m and 9.19 × 102 S/m, respectively. GO was over-reduced at P = 120 mW, with its resistivity and electrical conductivity being 3.72 × 10−3 Ω·m and 2.69 × 102 S/m, respectively. We further tested the ultrafast optical nonlinearity (ONL) of the as-prepared pristine and reduced GO with the femtosecond Z-scan technique. The results show that the behavior of ONL is reversed whenever GO is reduced in a controlled manner. More interestingly, the higher the ablation laser power is, the stronger the optical nonlinearity of r-GO is. In particular, the nonlinear absorption and refraction coefficients of the r-GO films reach up to 3.26 × 10−8 m/W and −1.12 × 10−13 m2/W when P = 120 mW. The nonlinear absorption and refraction coefficients reach 1.9 × 10−8 m/W and −3 × 10−13 m2/W, respectively, for P = 70 mW. GO/r-GO thin films with tunable photovoltaic response properties have potential for a wide range of applications in microelectronic circuits, energy, and environmental sustainability.

Vanadium Pentoxide and Bismuth Oxide Thin Films Deposition on PSi for Application in Solar Cells

Vanadium Pentoxide and Bismuth Oxide Thin Films Deposition on PSi for Application in Solar Cells

Recent Advances of Colossal Magnetoresistance in Versatile La-Ca-Mn-O Material-Based Films

Hole-doped manganese oxides exhibit a gigantic negative magnetoresistance, referred to as colossal magnetoresistance (CMR), owing to the interplay between double-exchange (DE) ferromagnetic metal and charge-ordered antiferromagnetic insulator/semiconductor phases. Magnetoresistive manganites display a sharp resistivity drop at the metal–insulator transition temperature (TMI). CMR effects in perovskite manganites, specifically La0.67Ca0.33MnO3 (La-Ca-Mn-O or LCMO), have been extensively investigated. This review paper provides a comprehensive introduction to the crystallographic structure, as well as the electronic and magnetic properties, of LCMO films. Furthermore, we delve into a detailed discussion of the effects of epitaxial strain induced by different substrates on LCMO films. Additionally, we review the early findings and diverse applications of LCMO thin films. Finally, we outline potential challenges and prospects for achieving superior LCMO film properties.

High-Performance Hydrogen Sensing at Room Temperature via Nb-Doped Titanium Oxide Thin Films Fabricated by Micro-Arc Oxidation

High-Performance Hydrogen Sensing at Room Temperature via Nb-Doped Titanium Oxide Thin Films Fabricated by Micro-Arc Oxidation

Unveiling the Origin of the Scale-Dependent Conductivity of Ni3(HITP)2 Metal-Organic Framework Thin Films.

Conductive metal-organic frameworks (MOFs) are crystalline, intrinsically porous materials that combine remarkable electrical conductivity with exceptional structural and chemical versatility. This rare combination makes these materials highly suitable for a wide range of energy-related applications. However, the electrical conductivity in MOF-based devices is often limited by the presence of different types of structural disorder. Here, the electrical transport characteristics of high quality Ni3(HITP)2 nanometer-thin films are reported. These findings reveal a tenfold difference in conductivity between the micro- and nano-scale, attributed to poor electrical connection among a limited number of crystalline grains. Average in-plane conductivity values at the micro- (σIP,micro = 0.7 ± 0.3 Scm-1) and nano- (σIP,nano = 6 ± 3 Scm-1) scales is determined, and the value of the inter-grain resistance, Rinter-grain = 40 kΩ is found. Using a 2D resistor network model with a 40 kΩ base resistance and scattered higher resistances, surface potential maps of in-operando MOF-based electrical devices are successfully reproduced. Additionally, a structure-property relationship that links the density and spatial distribution of electrical failures in inter-grain connections to the observed micro-scale conductivity in MOF thin films is established.

Thermal annealing effects on optical and dielectric properties of TiOPc thin films for optoelectronic and photonic applications

Thermal annealing effects on optical and dielectric properties of TiOPc thin films for optoelectronic and photonic applications

Picosecond Laser Direct Writing of Micro-Nano Structures on Flexible Thin Film for X-Band Transmittance Function

Recently, ultrafast laser direct writing has become an effective method for preparing flexible films with micro-nano structures. However, effective control of laser parameters to obtain acceptable micro-nano structures and the effect of micro-nano structure sizes on function of the film remain challenges. Additionally, flexible films with high X-band transmittance are urgently required in aerospace and other fields. In this work, we evaluate the feasibility of applying picosecond laser direct writing for fabricating micro-nano structures on the surface of flexible thin film and the relationship between the size of square columnar micro-nano structures and the transmittance of the flexible thin film. The results show that an array of square columnar micro-nano structures was achieved by picosecond laser direct writing on the surface of flexible thin film (Au-SiO2-PI) with a thickness of 50 µm. Additionally, excellent micro-nano structures morphology of the square columnar arrays without burning through or destroying were obtained by laser direct writing with a pulse power and frequency of 2 W and 100 KHz, respectively. The results also show that the X-band transmittance was effected by the characteristic of the square columnar array on the surface of the flexible thin film. The X-band transmittance was significantly increased by decreasing the length of the square column on the surface of the flexible thin film. The X-band transmittance was slightly increased by decreasing the width of the groove of the square column on the surface of the flexible thin film.