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This article presents a highly sensitive gold/Ti 3 C 2 T x coated photonic crystal fiber (PCF)-based surface plasmon resonance (SPR) sensor for cancer cells detection. The hybrid gold/Ti 3 C 2 T x layer is coated circularly over PCF for occurrence of SPR by coupled mode theory. The simulations and numerical analysis are done by the finite element method. The resonance wavelength shift is measured between normal and cancerous cell samples to estimate the wavelength sensitivity and resolution. In results, the maximum wavelength sensitivity for breast cancer MCF-7 cells is achieved as 10,714 nm/RIU in x-polarization mode and 13,071 nm/RIU in y-polarization mode with very low resolution of 10−6 RIU. The impact of the MXene (Ti 3 C 2 T x) thin film on sensitivity is also observed. In addition, the optimization of parametric variation is analyzed with machine learning technique with low mean squared error of 0.01525. <2% error is obtained in sensitivity analysis with multilayer perceptron regressor. Due to the advanced results and machine learning application, this sensor can be used as a fast, efficient and low-cost cancer disease detection device. [Display omitted] • A gold/Ti 3 C 2 T x coated PCF based SPR sensor is presented and numerically analyzed for detecting various cancer cells. • Vertical confinement path is used to transform the energy from core mode to SPR mode with external sensing approach. • The normal to cancerous cell is detected by measuring the corresponding resonance wavelength shift. • The Multilayer Perceptron regressor has been employed on ANN model for predicting the output of PCF-SPR sensor. [ABSTRACT FROM AUTHOR]

In this article, an Au/Ti 3 C 2 T x MXene hybrid layered D-shaped Photonic Crystal Fiber (DPCF) based Surface Plasmonic Resonance (SPR) biosensor is proposed. The D-shape of PCF is used to make the sensor practically more feasible. The MXene-Au hybrid thin films are placed over the DPCF to induce the surface plasmon polariton (SPP). The resonance wavelength shift occurs when analytes refractive index (RI) is changed. The numerical analysis has been performed by finite element analysis. The results have shown the wavelength sensitivity of 7000 nm/RIU and 13,000 nm/RIU for MXene layer thickness of 14 nm and 27 nm respectively. On comparing, it has been observed that the MXene/Au layered sensor has achieved 3.5 to 6.5 times higher wavelength-sensitivity compared to without MXene thin film. In addition, sensing parameters like resolution, amplitude sensitivity and figure of merit has also been investigated. The proposed sensor is used for sensing the analytes having RI range of 1.33–1.39. The range of RI covers most of the blood cells compositions, cancerous cells, protein and viruses. Therefore, this study can facilitate the use of MXene material with D-shaped PCF to detect the biochemical and chemical liquids. Photonic crystal fiber, MXene material, Gold, Surface plasmon resonance, Biomolecules. • A surface plasmon resonance sensor based on D-shape of PCF is proposed using Mxene/Au material thin film for the first time. • The sensing analytes having a refractive index (RI) range of 1.33–1.39 are used. The range of RI covers most of the bio analyte's RI like blood cells, cancerous cells, RNA/DNA, malaria-infected RBCs, protein and viruses. • The results show the wavelength sensitivity of 7000 nm/RIU and 13,000 nm/RIU for Mxene layer thickness 14 nm and 27 nm respectively. • On comparing, it has been observed that the Mxene/Au layered sensor has 3.5 to 6.5 times higher wavelength-sensitivity than without the Mxene thin layer. • The effect of the Mxene layer on other sensing parameters like resolution, amplitude sensitivity and figure of merit has also been investigated. [ABSTRACT FROM AUTHOR]

Fatigue failure in ferroelectrics has been intensively investigated in the past few decades. Most of the mechanisms discussed for ferroelectric fatigue have been built on the “hypothesis of variation in charged defects”, but these are rarely evidenced by experimental observation. Here, using a combination of complex impedance spectra techniques, piezoresponse force microscopy and first-principles theory, we examine the microscopic evolution and redistribution of charged defects during the electrical cycling in BiFeO 3 thin films. The dynamic formation and melting behaviors of oxygen vacancy ( V O ) order are identified during the fatigue process. It reveals that the isolated V O tends to self-order along grain boundaries to form a planar-aligned structure, which blocks the domain reversals. Upon further electrical cycling, migration of V O within vacancy clusters is accommodated with a lower energy barrier (∼0.2 eV) and facilitates the formation of a nearby-electrode layer incorporated with highly concentrated V O . The interplay between the macroscopic fatigue and microscopic evolution of charged defects clearly demonstrates the role of ordered V O clusters in the fatigue failure of BiFeO 3 thin films. [ABSTRACT FROM AUTHOR]

Abstract: Optical, magnetocapacitance and dielectric properties of different composite films of BiFeO3–poly(vinylidene-fluoride) (with concentration of BiFeO3; 70, 60, 50 and 40wt%) are reported here for first time. The grain size was observed to be ∼50nm by using atomic force microscopy. A peak in refractive index appears at ∼455nm, which is found to be shifting towards lower wavelengths, while simultaneously the value of the optical energy band gap is found to increase with an increase in the concentration of PVDF in the composite. It was observed that PVDF, which works as matrix, increases the magnetocapacitance. The magnetocapacitance (MC) of BFO60 (BiFeO3; 60wt%) was found higher than Nb doped BiFeO3, which may be useful for device applications. [Copyright &y& Elsevier]

Abstract: We report on the electronic charge transfer in cobalt doped fullerene thin films by means of near-edge x-ray-absorption fine structure (NEXAFS) spectroscopy measurement. Co-doped fullerene films were prepared by co-deposition technique and subjected to energetic ion irradiation (120MeV Au) for possibly alignment or interconnect of randomly distributed metal particles. Polarization dependent NEXAFS spectra revealed the alignment of Co and C atoms along the irradiated ionic path. The structural changes in Co-doped as-deposited and ion irradiated fullerene films were investigated by means of Raman spectroscopy measurements. Downshift of pentagonal pinch mode Ag(2) in Raman spectroscopy indicated the electronic charge transfer from Co atom to fullerene molecules, which is further confirmed by NEXAFS at C K-edge for Co-doped fullerene films. [Copyright &y& Elsevier]

Abstract: Nanocrystalline indium oxide-doped tin oxide thin film sensors have been synthesized using sol–gel dip-coating technique. The sensors were spin-coated with three different types of polymer namely polymethyl methacrylate (PMMA), poly-perfluorobutenyl vinyl ether (Cytop), fluoropolymer (Fluoropel). The room temperature sensor characteristics (response time, electrical response and recovery time) of the three sensors with different polymer coating were compared at hydrogen concentrations of 600, 1500, 6000 and 15,000ppm and at two different humidity levels of 14% and 65%. It was found that the polymer coating preserves the selective sensing property of indium oxide-doped tin oxide even at high humidity. The response kinetics of the sensors with different coatings has been compared. [Copyright &y& Elsevier]

Abstract: Modifications of the C70 molecule (fullerene) under swift heavy ion irradiation are investigated. C70 thin films were irradiated with 120MeV Au ions at fluences from 1×1012 to 3×1013 ions/cm2. The energetic ion impacts lead to the destruction of the C70 molecule. To investigate the stability of C70 fullerene, the damage cross-section and radius of the damaged cylindrical zones are evaluated by fitting the evanescence of C70 vibration modes recorded by Raman spectroscopy. Conductivity measurements together with Raman and optical absorption studies revealed that an irradiation fluence of 3×1013 ions/cm2 results in complete amorphization of the carbon structure of the fullerene molecules. [Copyright &y& Elsevier]

Abstract: Three phase transitions (face centered to simple cubic, surface rearrangement from (2×2) to (1×1) and glass transition) in fullerene thin films and the effect of 150MeV Ti ion irradiation on these transitions have been studied, using temperature dependence of electrical resistivity measurements. The structural properties of the C60 thin films are studied by X-ray diffraction, atomic force microscopy and UV–vis spectroscopy. It is observed that defect creation by ion irradiation in the films lead to quenching and broadening of structural phase transitions but the transition temperatures did not show significant shifting under ion irradiation. [Copyright &y& Elsevier]

Abstract: Thermally evaporated ZnO thin films have been irradiated with 100MeV Au8+ ions at different fluence from 5×1011 ions/cm2 to 5×1013 ions/cm2. The optical and structural properties of the irradiated and pristine films were studied using Fourier transform infrared spectroscopy (FTIR), UV–visible absorption spectroscopy, photoluminescence (PL), atomic force microscopy (AFM) and XRD. FTIR results showed that for low fluence, the transmittance of the film decreased and increased again at higher fluence but Zn–O bond remains unaffected by irradiation. As revealed from the absorption spectra, absorption edge is not changed by the irradiation but the optical absorption is increased. The AFM study of the films implied that roughness decreased at low fluence values up to 5×1012 ions/cm2 and at higher fluences the roughness increased. [Copyright &y& Elsevier]

The control of polarization rotation (PR) is a key issue of applying undoped zinc oxide (ZnO) as information storage devices. A systematic study of ZnO thin films by conducting piezoresponse force microscopy (PFM) technique on samples with different electrodes, film thicknesses, and deposition oxygen partial pressures, P O 2 allows disclosing the possible factors those affecting the PR behavior. The results clearly indicate that higher work function conductive material, such as Pt, is a promising candidature as the top electrode and bottom electrode to ensure the PR occur and maintain in ZnO films. From the effects of film thickness study, PR behavior can be observed in film downscaled to 15 nm. However, in order to avoid current leakage and maintain the rotated polarization state, thicker film with about 240 nm is preferred. In addition, in the film deposited with a low P O 2 (>5 × 10−6 Torr), more atomic point defects such as oxygen vacancy may lead the sample into a large leakage current and deteriorate the PR behavior. Hence, by this systematic study, it is proved that the PR behavior of undoped ZnO thin films can be optimized with proper deposition parameters. Image 1 • Possible factors affecting the PR behavior are studied comprehensively. • Pt is a promising electrode candidature for PR behavior comparing with Au and ITO. • Unambiguous PR behavior is found in film with a thickness reduced to 15 nm. • P O 2 below 5 × 10−6 Torr might hinder the PR behavior. [ABSTRACT FROM AUTHOR]

• Nickel sulphide nano-particles was successfully synthesized and incorporated in the thin film organic solar cell. • NiS is found to be an important dopant for improving photons harvesting in thin film polymer solar cell. • Local surface plasmon resonance of NiS in polymer blend matrix is responsible for high optical absorption. Nickel sulphide (NiS) nano-composite were synthesized and used as dopant in the hole transport layer of the thin film organic solar cell (TFOSC). The nano-particles are intended to assist in the charge transport processes at the interface between the active layer and the anode. Thin film solar cells were fabricated using photo-active layer composed of poly-3-hexylthiophene (P3HT) and (6-6) phenyl-C61-butyric acid methyl ester (PCBM) blend. The solar cells employed NiS doped PEDOT:PSS hole transport layer (HTL) which are investigated in terms of changes in optical and electrical properties of the films. The electrical properties of the newly fabricated solar cells showed significant improvement in photo-generated current as the result of reduced charge carrier recombination and enhanced charge transport processes at the interface. This in turn boost the power conversion efficiency (PCE) of the devices by 95% compared to the devices without NiS doped HTL. The observed PCE enhancement is attributable to the excitation of the localized surface plasmon resonance exhibited by the presence of NiS in hole transport layer. It is noted in the investigation that the performance of the solar cell is dependant on the concentration of NiS nano-particles in PEDOT:PSS layer. As consequence, the highest recorded PCE in this study was 6.03% at 0.1% NiS by weight, which is encouraging result for device fabrication in ambient laboratory condition. [ABSTRACT FROM AUTHOR]

This paper reports a single step reactive extrusion process for fabrication of thermally stable, polylactic acid grafted cellulose nanocrystal(PLA- g -CNC) nanocomposite films using dicumyl peroxide as crosslinking agent. PLA- g -CNC nanocomposites were recycled without significant breakage in the molecular structure of PLA. The grafted PLA chains shields the sulfate and hydroxyl groups of CNCs, thereby enhancing the compatibilization with PLA matrix and preventing thermal degradation during extrusion. NMR and FTIR spectroscopy studies showed that amorphous PLA chains grafted on CNC surface through C–C bonds formation. Presence of such chemical crosslinks led to efficient transfer of modulus of CNCs to PLA matrix, thereby improving the tensile strength and young's modulus by∼40% and∼490%,respectively. Recycling of PLA- g -CNC doesn't alter the molecular weight, thermal, crystallization and mechanical properties of the nanocomposites significantly. Therefore, the current study provides a novel approach for fabricating CNC-reinforced-PLA nanocomposites which can be easily recycled and reused for multiple cycles. [ABSTRACT FROM AUTHOR]

Abstract: Thin films with ZnO nanocrystals in silica were synthesized by rf reactive magnetron co-sputter deposition and post-annealing. The films were deposited from a ZnO/Si composite target in an rf oxygen plasma. The deposited films were annealed in air/vacuum at high temperatures to grow ZnO nanocrystals. The deposited and annealed films were characterized by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), uv–vis spectroscopy (UV–VIS) and photoluminescence (PL) measurements. FT-IR results of the films show the vibrational features of Si–O–Si and Zn–O bonds. UV–VIS spectra of the deposited film shows the band edge of ZnO. The XRD results of the films annealed at 750°C and 1000°C indicate the growth of ZnO nanocrystals with average crystallite sizes between 7nm and 26nm. PL measurements of the deposited film show a broad visible luminescence peak which can be due to ZnO. These results suggest the growth of ZnO nanocrystals in silica matrix. [Copyright &y& Elsevier]

This work reports on direct crystallization of PbZr 0.53 Ti 0.47 O 3 (PZT) thin films on glass and polymeric substrates, using pulsed thermal processing (PTP). Specifically, xenon flash lamps deliver pulses of high intensity, short duration, broadband light to the surface of a chemical solution deposited thin film, resulting in the crystallization of the film. Structural analysis by X-ray diffraction (XRD) and transmission electron microscopy show the existence of perovskite structure in nano-sized grains (≤5 nm). Local functional analysis by band excitation piezoelectric spectroscopy and electrostatic force microscopy confirm the presence of a ferroelectric phase and retention of voltage-written polarization for multiple days. Based on structural and functional analyses, strategies are discussed for optimization of pulse voltage and duration for the realization of crystalline ferroelectric thin films. For ∼200 nm-thick PZT films on glass substrates, 500 μs-long pulses were required for crystallization, starting with 100 pulses at 350 V, 10 or 25 pulses at 400 V and in general lower number of pulses at higher voltages (resulting in higher radiant energy). Overall power densities of >6.4 kW/cm2 were needed for appearance of peaks corresponding to the perovskite phase in the XRD. Films on glass processed at 350–400 V had a higher degree of 111-oriented perovskite grains. Higher applied radiant energy (through increased pulse voltage or count) resulted in more random and/or partially 001-oriented films. For ∼1 μm-thick PZT films on polymeric substrates, 10 to 25 250 μs-long pulses at voltages ranging between 200 to 250 V, corresponding to power densities of ∼2.8 kW/cm2, were optimal for maximized perovskite phase crystallization, while avoiding substrate damage. [ABSTRACT FROM AUTHOR]

• Novel third-generation Ovonic memory materials have been synthesized. • Observed the significant electrical switching in thin-film samples. • Correlation between thermal stability and threshold switching voltage has been found. • Meyer-Neldel rule is observed in both d.c. conduction and resistive switching. The objective of the present research is to investigate the consequences of the incorporation of a small amount of Cd on the electrical switching behavior at high electric field 104 V/cm in Se 78-x Te 20 Sn 2 Cd x (x = 0, 2, 4, and 6) thin films. The thermal evaporation method has been utilized for thin-film deposition on a highly polished pyrographite substrate. The current-voltage (I-V) characteristics for the thin films of the examined samples exhibit a resistive switching of memory-type. The effect of ambient temperature and Cadmium content on the switching characteristics and voltage has been studied. The exponential decay in the observed average value of the switching voltage (V th) is found with the rise in temperature and Cd addition as well. An endeavor had been done to study the observed compositional dependence in terms of the thermal-induced glass transition temperature (T g), thermal stability, chemical bond approach, and lone-pair electrons (LP). On metal addition (Cd), the threshold voltage, glass transition temperature, and lone-pair electrons decrease while the chemical order network increases by the increase of the Cd-Se homopolar bonds. The switching phenomenon in amorphous Se 78-x Te 20 Sn 2 Cd x (0 ≤ x ≤ 6) thin films is elucidated according to an electro-thermal model based on the Joule-heating effect. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: It was found that Langmuir–Blodgett (LB) deposition process led to the direct formation of ferroelectric β phase in poly(vinylidene fluoride) (PVDF) homopolymer ultra-thin films, in which the molecular chains were parallel to the substrates and the dipoles were aligned perpendicular to the substrates. Theoretical analysis and experimental results further showed that the mechanism of forming the β phase and the dipole orientation were attributed to the hydrogen bonds formed between the PVDF molecules and water through the LB deposition. A large local effective piezoelectric coefficient (d zz) of −49.4 pm/V was observed in the self-polarized PVDF LB film. [Copyright &y& Elsevier]