November 2023Nov 01, 2023Current IssueVol. 55

November, 2023 | Volume 55

• Article 2023-11-30

  

  Effect of Bi(Zn1/2Nb2/5)O3 addition on phase transition and energy storage properties of BaTiO3 ceramics

  Ma, Cuiying; Zhang, Ruiying; Zhang et al.

  Curr. Appl. Phys. 2023; 55: 1-8

  https://doi.org/10.1016/j.cap.2023.08.012

  Abstract : Bi(Zn1/2Nb2/5)O3-modified BaTiO3 ceramics were designed with formula (1‒x)BaTiO3‒xBi(Zn1/2Nb2/5)O3 (0 ≤ x ≤ 0.15) and fabricated using conventional solid-state route. With increasing Bi(Zn1/2Nb2/5)O3 concentration, grain volume increased and phase structure was transformed from tetragonal to pseudo-cubic. Dielectric properties changed from temperature-dependent to temperature-insensitive and curves were flattened. Additionally, higher pseudo-cubic phase content induced slim P-E loop and low Pr. Therefore, 0.94BaTiO3‒0.06Bi(Zn1/2Nb2/5)O3 ceramic achieved energy storage density of 1.85 J/cm3 and high energy efficiency of 91.2% under electric field of 230 kV/cm. This energy storage density was 5 times higher than that of pure BT ceramic. Meanwhile, energy storage properties of this ceramic exhibited excellent thermal stability in the range of 30–120 °C and good frequency stability over 10–100 Hz. This work provides promising alternative option in energy storage materials. © 2023 Korean Physical Society

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  Elsevier

• Article 2023-11-30

  

  Multifunctional properties of tin oxide nanoparticles synthesized by green and chemical approach

  Uday, Y.S.; Manjunatha, H.C.; Vidya et al.

  Curr. Appl. Phys. 2023; 55: 9-15

  https://doi.org/10.1016/j.cap.2023.08.003

  Abstract : Herein, we report the synthesis of SnO2 nanoparticles by combustion method using two reducing agents. One with urea as a fuel (SnO2U) and another one with Azadirachta indica leaves extract as a reducing agent (SnO2N) and calcined at 500oC for 3 hrs. The synthesized samples are characterized using different techniques. The Bragg reflections confirms the formation of pure tetragonal SnO2 NPs. The surface morphological analysis clearly indicates the formation of irregular shaped agglomerated NPs. The agglomeration and particle size was found to be more in SnO2U NPs. The estimated direct energy bandgap using Tauc's relation was found to be 3.75 and 3.37 eV for SnO2U and SnO2N respectively. Further, Photoluminescence excitation, emission, CIE and CCT analysis was performed. Thus, the present sample might be used as a nanophosphor material in Cool and Warm blue light emitting diodes. The cytotoxic properties against HeLa and MCF7 cells and compared the percentage of viability and cell death with standard chemotherapy drug Cisplatin. Theoretically, X-ray/gamma ray absorption properties such as mass attenuation coefficient (MAC) SnO2U and SnO2N NPs were evaluated which might finds an application in nuclear radiation dosimetry. © 2023 Korean Physical Society

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  Elsevier

• Article 2023-11-30

  

  Intrinsic rotation of fusion plasmas induced by the ion-neutral charge exchanges

  Lee, Kwan Chul; Lee, Sang Gon

  Curr. Appl. Phys. 2023; 55: 16-21

  https://doi.org/10.1016/j.cap.2023.08.008

  Abstract : A quantitative driving mechanism of the spontaneous plasma rotation is analyzed by the plasma collisions with the neutrals. The origin of the plasma rotation on fusion devices without external momentum input has been an intensive research subject for more than two decades and no quantitative explanation is available so far. This new intrinsic rotation analysis finds that there is an unbalanced electrical force exchange between the ion and the electron induced by the ion-neutral charge exchange reactions. The electrons give most of the electrical force induced by the toroidal E-field to the ions, but the ions give a significant part of the electrical force to the neutrals. This unbalanced force generates toroidal rotation of ions in a counter-current direction. The rotation magnitude is determined by the frequencies of collisions between plasma and neutrals. A calculation method for the intrinsic rotation based on the measured parameters and simulated unknown parameters is established. The evolution of calculated intrinsic rotation by this method is well agreed with the experimental measurement on KSTAR. It is also found that the most determinant parameter for the intrinsic rotation is the impurity concentration and the variation by the neutral density change is relatively small. © 2023 The Authors

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  Elsevier

• Article 2023-11-30

  

  Significant effects of mesoporus Bi2S3/ poly (vinylpyrrolidone) composites on DSSC performance

  Shaikh, Rahilah S.; Rajput, Rekha B.; P et al.

  Curr. Appl. Phys. 2023; 55: 22-33

  https://doi.org/10.1016/j.cap.2023.08.009

  Abstract : Herein, we report bismuth sulfide (Bi2S3) synthesis via the hydrothermal method for low-cost dye-sensitized solar cell (DSSCs). A detailed characterization of Bi2S3/poly (vinylpyrrolidone) (PVP) material was carried out by various characterization technique. The J–V curves and cyclic voltammogram were examined using a solar simulator to evaluate power conversion efficiency (PCE) and its catalytic activities. The experiment was then repeated with a different amount of PVP agent surfactant to improve their power conversion efficiency. With the help of 1.0 g PVP, its conversion efficiency reached 3.35%, which was superior to the Bi2S3 without PVP addition. The results indicate that the Bi2S3/1.0 g PVP composites is a promising alternative to the costly Pt CE and can minimize the cost of dye-sensitized solar cells. © 2023 Korean Physical Society

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  Elsevier

• Article 2023-11-30

  

  Solution processable visible-light and color-selective image sensor with a ZnO/QDs/ZrO2 sandwich structure

  Jeong, Jun Hyung; Kang, Seong Jae; Kang et al.

  Curr. Appl. Phys. 2023; 55: 34-43

  https://doi.org/10.1016/j.cap.2023.08.013

  Abstract : Quantum dots (QDs) are emerging materials for optoelectronic devices because of their facile tunable bandgap and solution processability. However, overcoming inherent problems, such as vulnerability to atmospheric moisture and the persistence photoconductivity (PPC) effect originating from trap states, is necessary. We proposed a method to enhance the stability and reduce the PPC effect by adding a ZrO2 passivation layer above the QDs layer. The ZrO2 layer effectively reduced the trap state of the QDs, passivated the QDs from external environmental oxygen and moisture, and simultaneously acted as an additional channel. Interfacial analyses were conducted using X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), time-resolved photoluminescence (TRPL), and high-resolution transmission electron microscopy (HR-TEM) measurements. Hence, the device showed enhanced photoresponsivity and photosensitivity of 2.6 × 103 A/W and 6.67 × 105, respectively. Additionally, the device showed a highly reduced PPC effect with a rate of current increase of 0.017 under periodic 635 nm wavelength light illumination. Moreover, it showed reliable long-term stability over 30 days under a relative humidity of ∼40%. Therefore, a color-selective image sensor was successfully demonstrated, and the device could recognize red/green/blue colors owing to its reduced PPC effect and high stability. Our results suggest a useful method for developing next-generation QD-based transparent optoelectronic devices. © 2023 Korean Physical Society

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  Elsevier

• Article 2023-11-30

  

  Optimal of black anti-static AZO/Al2O3-SiO2-VxOy coatings for spacecraft stray light on high silicon aluminum alloys

  Li, Zhenyu; Zhou, Zhihua; Wang et al.

  Curr. Appl. Phys. 2023; 55: 44-52

  https://doi.org/10.1016/j.cap.2023.06.006

  Abstract : It is still challenging to prepare an anti-static and anti-stray astigmatism coating on the high silicon aluminum alloy (>50 wt% Si, Al-50Si) for space material under extreme environments. To address these issues, the black anti-stray light coating with enhanced conductivity on the chemical etching surface of high-silicon Al-70Si alloy were successfully fabricated by the combination of plasma electrolytic oxidation (PEO) technology and deposited aluminum doped zinc oxide (AZO) transparent conductive film by magnetron sputtering technology. The microstructures, phase, elemental compositions, light absorption performance and electrical resistivity of coatings were tested and analyzed by SEM, EDS, XRD and XPS spectroscopy. The effects of process parameters including current density and AZO sputtering times on the structure, optical and electrical properties of the film layer were systematically studied. Convection through the fixation effect in the etched Al-70Si alloy porous layer promoted the internal heat and mass transfer during PEO process which is similar to previous reported mechanism of filling of cracks and pores by nanoparticles leading to the layer densification. The PEO coating had the highest absorptivity of 0.946 and it only decreased to 0.939 after AZO sputtering, at the same time the coating has the lowest resistivity of 1.04 × 107 Ω/sq, indicating excellent anti-stray light and antistatic ability. This two-step route pave the way to improve the conductivity without compromising optical properties of PEO coating on the high silicon aluminum alloy (>50 wt% Si, Al-50Si) for space material. © 2023 Korean Physical Society

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  Elsevier

• Article 2023-11-30

  

  Impact of electroplating salt (AgNO3) concentration on the morphological, optical, electrical and thermoelectric properties of silver assisted electrochemically etched silicon nanowires (SINWs)

  Nath, P.; Bano, N.; Sarkar et al.

  Curr. Appl. Phys. 2023; 55: 53-63

  https://doi.org/10.1016/j.cap.2023.09.002

  Abstract : Silicon nanowires (SINWs) are fabricated through silver assisted electrochemical etching route at room temperature. Very high yield vertically aligned SINWs are obtained through this electrochemical etching route. The effect of electroplating salt concentration on the properties of SINWs is investigated. Surface morphology shows grass like structures with increase of length and decrease of diameter with increasing salt concentration. Atomic force microscopy reveals increased surface roughness. UV–Visible spectra show reduced reflectivity enabling the material to be efficient for antireflection coatings. Photoluminescence spectra exhibit multiband transitions. Raman spectra show asymmetric peak broadening with peak downshift. Electrical properties display enhancement of SINWs current with higher AgNO3 concentration due to increased surface mediated effects. Current - voltage characteristics follow thermionic emission model. Samples exhibit space charge limited conduction at higher bias voltages due to presence of traps or crystal imperfections. Prepared samples are also investigated for thermoelectric properties and the results show enhanced Seebeck coefficient with increasing AgNO3 concentration. © 2023 Korean Physical Society

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  Elsevier

• Article 2023-11-30

  

  An investigation of the effects of a high valence state dopant (Zr4+) and the experimental insertion of two Na+ ions in the NaVOPO4 matrix

  A, Neelaveni; K, Senthil; R et al.

  Curr. Appl. Phys. 2023; 55: 64-74

  https://doi.org/10.1016/j.cap.2023.09.001

  Abstract : In this work, we attempt to incorporate two Na atoms into the NaVOPO4 matrix, which transforms the matrix into Na2VOPO4. To achieve this, we adjusted the phase parameters and used a facile synthesis method like the sol-gel-assisted hydrothermal technique. However, at high temperatures, the oxygen environment around the V atom changes, introducing the new phase Na2V(PO4)2 matrix into NaVOPO4. High valence state ions are required to support the active sites, keep the oxygen environment around them at a high temperature, and function well as a dopant for the NVP matrix. As a result, the Zr4+ is incorporated into the NVP matrix and it significantly enhances the tetragonal phases by enhancing (101), (112) planes. By substituting Zr4+ ion, the specific capacity of NVP is raised from 0.8268 mAh/g to 4.214 mAh/g at the scan rate of 10 mV/s. © 2023 Korean Physical Society

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  Elsevier

• Article 2023-11-30

  

  Temperature dependence of complete sets of material constants of Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 crystals using different poling methods

  Tang, Haiyue; Zhang, Wenjie; Yang et al.

  Curr. Appl. Phys. 2023; 55: 75-81

  https://doi.org/10.1016/j.cap.2023.09.005

  Abstract : The complete sets of material constants of -oriented two wafers (HP: high-performance and LP: low-performance) using direct current poling (DCP) and alternating current poling (ACP) were investigated. ACP can improve the longitudinal and transverse piezoelectric properties (about 20% increase in both d31 and d33) and decrease the shear properties (about 40% decrease in d15). The compliance constants SEij of both ACP HP and LP samples have the similar change trend (the absolute of SE11, SE12, SE13, SE33, SE66 increasing, the SE44 decreasing), while most stiffness constants CEij of both ACP HP and LP samples show the different change trend. The values of CE11, CE12, CE13 of ACP LP samples increase by at least 50% while ACP HP samples decrease by about 5%. As temperature elevated, the dielectric properties (εT11/ε0, εT33/ε0), piezoelectric properties (d15, d31, d33) and electromechanical coupling coefficients (k15, k33) increased steadily, while the k31 keep stable. © 2023 Korean Physical Society

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  Elsevier

• Article 2023-11-30

  

  An investigation using DFT methods on the electronic and optical properties, and mechanical behavior of the wurtzite ZnO1-xTex ternary alloy

  Moussa, Rabah; Djalab, Yacine; Maache et al.

  Curr. Appl. Phys. 2023; 55: 82-92

  https://doi.org/10.1016/j.cap.2023.09.004

  Abstract : The wurtzite structure of the ZnO1-xTex ternary alloy was analyzed through the utilization of density functional theory (DFT) within the WIEN2k code. This investigation examines its structural, electronic, optical, and elastic properties. The results have indicated a nonlinear variation in the lattice constants of the alloy mixture. Moreover, the direct bandgap energies of the materials, including the binary mixtures ZnO and ZnTe, as well as their ordered alloy counterparts (ZnO0.75Te0.25, ZnO0.5Te0.5, and ZnO0.25Te0.75), substantiate the semiconducting characteristics of these compounds. The densities of the states (DOS) for ZnO and ZnTe binary compounds and ZnO0.75Te0.25 ternary alloy are chosen as prototypes. The reflectivity and absorption coefficients versus photon energy and the real and imaginary components concerning the refractive index are estimated at ternary alloys and their binary constituents. The ductile and brittleness nature of alloys are transformed with the composition, and they have strong ionic bonding. © 2023 Korean Physical Society

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  Elsevier