Kong, DehaoJi, MingxiChen, QichengZhang, Yingjin...
13页查看更多>>摘要：In this paper, the optical and thermodynamic properties of Fe-doped Ca-based materials were revealed by the Density Functional Theory method. The results showed that the doped Fe atom was oxidized by O2- to form inert structures, enhancing the resistance of CaO to sintering at high temperatures. More importantly, the doping of Fe enabled the electrons to jump between energy levels more easily, improving the light absorption ability of Cabased composites. Meanwhile, a qualitative analysis of the thermodynamic parameters of the composites was carried out. It was found that the thermal conductivity and specific heat capacity of the composites decreased with increasing iron content, while the Debye temperature increased. Besides, the doping of Fe leads to the reduction of activation energy of the reaction due to the formation of electron-deficient O sites on the surface, resulting in a suppression of the reaction rate between CaO and CO2.
原文链接:
NSTL
Elsevier
Debbarma, ManishGhosh, DebankitaChattopadhyaya, Surya
13页查看更多>>摘要：First-principle calculations show transformation of indirect-band-gap zinc-blend beryllium chalcogenide to direct-band-gap mercury-beryllium-chalcogenide HgxBe1-xS, HgxBe1-xSe and HgxBe1-xTe semiconductor ternary alloys through doping of Hg atoms at different concentrations. The lattice constant increases but fundamental band-gap reduces nonlinearly in each system with increasing mercury-composition. Effective mass of electrons is much less than that of holes in each specimen. Computed thermoelectric properties of ternary alloys show their p-type conductivity and also their compatibility in thermoelectric applications in the 400-1200 K temperature range. Peaks in the dielectric function spectra of ternary alloys in the UV region are originated from chalcogen-p level of valence band to Be-3s, 2p and Hg-7s levels of conduction band and they confirm their compatibility in UV optoelectronic applications. Calculated static optical constants of the specimens under any ternary system decrease with increasing band-gap and vice versa. Oscillator strength, optical energy-gap and skin-depth of ternary alloys have also been calculated.
原文链接:- NSTL
- Elsevier
Amuthan, T.Sanjeevi, R.Kannan, G. R.Sridevi, A....
9页查看更多>>摘要：Under visible-light irradiation, a novel CuFe2O4/ZnS nanocatalyst was employed in a two-step method for removal of organic dyes. The XRD, FTIR, UV-Vis spectroscopy, PL, and FESEM analysis were used to characterize the synthesized CuFe2O4/ZnS nanocomposites (NCs). The photocatalytic activity results expose better photodegradation performance by using the CuFe2O4/ZnS nanocatalysts. The degradation efficiency of MB and CV dyes were achieved at 82 and 87% within 120 min under visible-light illumination. As a result, CuFe2O4/ZnS NCs outperform CuFe2O4 and ZnS in photocatalytic performance owing to efficient photogenerated charge carriers via the development of p-CuFe2O4-n-ZnS heterojunction. The synthesized CuFe2O4/ZnS nanocatalyst can be successfully used for waste water treatment purification as a result of its photodegradation performance.
原文链接:- NSTL
- Elsevier
Abdulqadir, Sarbast W.Majeed, Hawri O.Abdullah, Nzar Rauf
7页查看更多>>摘要：ABS T R A C T We study a photonic circuit consisting of a quantum dot, QD, coupled to a photon cavity over a wide range of temperature up to room temperature. A key component of such a system is presented here in the form of a Purcell-enhanced single-photon source based on Cavity Quantum Electrodynamics, cQED. We use a real set of pure dephasing data extracted from experimental measurements of InGaAs QD to calculate the effective QD-cavity coupling strength, the Purcell factor, and the single photon efficiency emerged from the QD-cavity system in the cases without and with detuning. In the non-detuned system, the effective coupling strength between the QD and the resonator decreases with increasing temperature, results in a decrease in efficiency. However, when the temperature of the QD-cavity system increases under Purcell effect conditions, the detuned QD-cavity system induces spontaneous emission rate enhancement. As a result, we found that the increase in efficiency can be obtained under a certain condition, when the maximum effective coupling strength and the Purcell factor are related to the spontaneous emission and the pure dephasing rates. Additionally, the influences of the pumping mechanism on the efficiency of the QD-system were examined and showed that the pumping process can be used to further increase in efficiency. Our results can be advantageous for advanced quantum optics applications once temperature is taken into account.
原文链接:- NSTL
- Elsevier
Kashyap, VikasKumar, ChandraKumar, VivekChaudhary, Neeru...
8页查看更多>>摘要：The Light management is a fundamental study to improve the solar cell and photoelectrical devices conversion efficiency. Here, the spectral responses of reflection and absorption characteristics of random silicon nanowires (Si-NWs) arrays of different lengths and doping type has been investigated. The Si-NWs have been synthesized by metal induced etching (MIE) approach have dimensions of Sub-wavelength regime. These Si-NWs arrays show efficient light trapping and low reflectance than bare Si due to suppression of Fresnel reflection substantially over a wide spectral range. The comparative study of light trapping in Si-NWs, fabrication by using n-type and p-type Si wafer have been explored to add new dimension in the field of photovoltaic application. Here, diffuse reflection spectra have been used to analyzed the light-scattering properties of Si-NWs, which reveal that the diffuse scattering decreases as the pore depth increases. The field distribution of Si-NWs is simulated using finite differential time domain (FDTD) method, results shows that reflectance could be modified due to light absorption driven by multiple scattering inside the structure reaching high values of apparent absorbance. Current-voltage (I-V) curves have been measured under illumination at standard testing conditions (STC), i.e., 300 K, 1000 W/m(2) and 1.5 a.m. global by using solar simulator. These measurement studies indicate that dopant (n-type and p-type) have been effectively influenced the photovoltaic parameters. I-V curve indicated that the power conversion efficiency (PCE) of n-type and p-type doped Si-NWs exhibited PCE of 3.94% and 4.01% respectively.
原文链接:- NSTL
- Elsevier
Balmuchu, Shashi PriyaDobbidi, Pamu
10页查看更多>>摘要：In this study, La-doped bismuth ferrite (BLFO), Bi1-xLaxFeO3 (x = 0.00, 0.005, 0.007, 0.01) compositions have been synthesized via a solid-state method to investigate their structural, electrical, magnetic, ferroelectric, and optical properties. All the synthesized ceramics were found to be in rhombohedral distorted perovskite structures with R3c symmetry. A significantly reduced grain size with improved dielectric properties (enhanced dielectric constant and reduced dielectric loss) was observed with La doping up to composition x = 0.007. The magnetization study revealed that substitution of La in BFO enhances remnant magnetization (M-r) and coercive field (H-c). The ferroelectric study manifested that composition x = 0.007 retained a higher polarization value among all the ceramics. Moreover, the optical study exhibited that with doping, the bandgap increased from 2.49 eV for BFO to 2.64 for x = 0.007 ceramic. For the last composition x = 0.01, the bandgap decreased to 2.43 eV, which can be advantageous for magnetic photocatalysts applications.
原文链接:- NSTL
- Elsevier
Shu, ChangqingYao, ZhengjunLi, XiaolinDu, Wenbo...
11页查看更多>>摘要：In this study, electron beam current was used to modify the surface of CoCrCuFeNiVx (x = 0, 0.6, 1.0) prepared by sintering to improve wear resistance. Thermal behavior, microstructure, hardness and wear resistance of the alloy were investigated with conclusions below. CoCrCuFeNiV alloy is composed of three phases (FCC, Cu-rich phase, V-rich phase) after sintering and electron beam remelting. V is beneficial to reduce the enthalpy of CoCrCuFeNiVx and promote the stabilization of FCC solid solution phase. The hardness of CoCrCuFeNiV can reach up to 408.4HV, which is 35.4% higher than CoCrCuFeNi (301.5HV). Moreover, the wear resistance is greatly improved by V due to the formation of alloy hardening layer and oxide film on the surface, and the wear rate is reduced by 80.6%. The wear mechanism of CoCrCuFeNiV is mainly abrasive wear, supplemented by adhesive wear and oxidative wear.
原文链接:- NSTL
- Elsevier
Morocho, A. A.Pilyuk, E. A.Zakhvalinskii, V. S.Nikulicheva, T. B....
9页查看更多>>摘要：In this work, we present first AC conductivity measurements of both amorphous and polycrystalline Cd3As2 thin films (~50 nm) in the frequency range 25-106 Hz and temperature range 10-300 K. Cd3As2 thin films were grown by non-reactive AC magnetron sputtering. Both samples show a strong frequency dependence of the total conductivity in the order of 10(4) omega(-1) cm(-1). It was found that the DC conductivity, deduced from the total conductivity of Cd3As2 thin films, increases with increasing temperature. The experimental results indicate exponent values s > 1 and s > 2, which contradicts the universal dynamic response. In Cd3As2 films is observed a crossover of metal-semiconductor type at low temperatures, which is characteristic of topological materials. The results show a clearly frequency dependence of the mechanism of AC conductivity of Cd3As2 films in a wide range of temperatures.
原文链接:- NSTL
- Elsevier
