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Performance enhancement of copper indium diselenide photovoltaic module using inorganic phase change material
摘要： The work presents the method to increase the electrical efficiency and power output of photovoltaic (PV) panel with the use of phase change material (PCM). CaCl2.6H2O–Fe3Cl2.6H2O eutectic has a suitable melting point and high latent heat for temperature regulation of PV panel. The work has been focused on the experimental setup and simulation heat extraction from the PV panel with the use of ANSYS software. A modification of copper indium diselenide (CIS) PV module from Solar Frontier (SF170-S) was made with a eutectic mixture (70:30) of calcium chloride hexahydrate (70%) and iron (III) chloride hexahydrate phase change material. The cell temperature of the PV panel with and without PCM was measured and compared for two typical days. The simulation of the PV-PCM systems comprising both PV panels was performed using ANSYS (fluent) software, followed by the comparison of the results actual experimental data. The experimental results show that the maximum temperature difference on the surface of PV panel without PCM was 9°C higher than that on the panel with PCM in a period of 1 day. Referring to experimental results, the calculation of the maximum and average increase of power gain was made for PV-PCM panel. Final results show that the electricity production of PV-PCM panel was higher for 96.55 Whr in a particular day of experimentation.
关键词： phase change material,ANSYS,electrical efficiency,power gain,photovoltaic module
更新于2025-09-23 15:21:01
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Anion-Substituted Garnets Ca3Mn2 – x(Ni, Co)xVyGe3 – yO12 (x = 0, 1; y = 0, 1, 2): Preparation and Characterization
摘要： Garnets with the structure similar to that of Ca3Mn2Ge3O12 have been prepared with simultaneous substitutions of Ge4+ by V5+ in tetrahedra and of Mn3+ by Ni2+ or Co2+ in octahedra. X-ray photoelectron spectroscopy (XPS) proved the absence of V4+ in tetrahedra of the lattice of the compounds prepared and determined the valences of elements in octahedral sites. The increasing d-cation size in octahedra is accompanied by an increase in unit cell volume regardless of the composition of tetrahedra (VyGe3 – y)O12. The electrical conductivity of Ca3Mn2 – x(Ni, Co)xVyGe3 – yO12 (x = 0, 1; y = 0, 1, 2) garnet ceramic samples and the calculated bandgap widths make it possible to classify them with medium-gap semiconductors.
关键词： garnet,crystallographic radius,tetrahedron,electrical conductivity,octahedron,bandgap width,d elements
更新于2025-09-23 15:21:01
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Influence of boron doping amount on properties of ZnO:B films grown by LPCVD technique and its correlation to a-Si:H/??c-Si:H tandem solar cells
摘要： Boron-doped ZnO:B (BZO) films with various doping levels have been prepared on large-area substrates by low pressured chemical vapor deposition technique. The influence of doping amount on electrical and optical properties of BZO films has been investigated. It is found that ZnO phase synthesis is hardly affected when the doping gas flow varies from 25 to 100 sccm, but the preferential orientation of grain growth is influenced progressively. It is interesting that there should be a threshold value of doping gas flow of 75 sccm that will cause an abrupt reduction in grain size of BZO and therefore dramatically weakens the light-scattering capacity of the film. It is also noted that the boron atoms doped in BZO films are partly electrically active, and moreover, the heavier doping level, the more inactive B atoms, which not only reduces carrier mobility, but also boosts a stronger light absorption due to enhanced impurity scattering. When the doping gas flow is 75 sccm, the BZO film can achieve a proper comprehensive property with a Rsq of 15.2 Ω/□, an average haze of 21.3% and an average TT of 80.2%. Using this film as the front electrode of a-Si:H/μc-Si:H solar cell, the optimum performance of the solar cell with a Jsc of 12.68 mA/cm2, a Voc of 1.385 mV, and an initial efficiency (η) of 11.83% was obtained.
关键词： a-Si:H/μc-Si:H tandem solar cells,Boron-doped ZnO:B films,doping amount,LPCVD technique,electrical and optical properties
更新于2025-09-23 15:21:01
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[Materials Horizons: From Nature to Nanomaterials] Advances in Polymer Sciences and Technology (Select Papers from APA 2017) || Structural and Morphological Analysis of Newly Synthesized CuO@Alginate Nanocomposite with Enriched Electrical Properties
摘要： CuO@Alginate (CuO@Alg) nanocomposite has been synthesized by simple, inexpensive and highly efficient Sol-Gel method. The morphology and structural properties of synthesized nanocomposite (CuO@Alg) and pure CuO nanoparticles have been analyzed as a function of temperature. The morphological and structural properties were investigated by using TEM, SEM, EDX, and X-ray diffraction. The crystalline nature of CuO nanocomposite showed by X-ray diffraction (XRD) pattern and average crystalline size was observed approximately 18.09 nm. The effect of size quantization on morphology was also observed. Dielectric behavior of CuO and CuO@Alg has been also studied as a function of increasing frequency by LCR meter. With the increase in frequency, the dielectric constant was found to decrease and alternative current (A.C.) conductivity value was found to increase. This study was also representing a useful step towards the establishment of a structure–property relationship for CuO nanocomposite.
关键词： Nanocomposite,Copper oxide,Electrical conductivity
更新于2025-09-23 15:21:01
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Tl2S-GeS GeS2 system: Glass formation, macroscopic properties, and charge transport
摘要： the previously obtained conductivity and A relevant approach was found to study the glass-forming region, macroscopic properties and electrical conductivity changes in the Tl2S-GeS-GeS2 system by analysing two composition glass lines (Tl2S)x(GeS2)100-x (0 ≤ x ≤ 50) and (Tl2S)10(GeS)x(GeS2)90-x (0 ≤ x ≤ 90) together with three thallium containing crystalline compounds Tl4Ge4S10, Tl4Ge2S6 and Tl4GeS4. The crystallization ability variation in the binary Tl2S-GeS2 system can be explained comparing the structural characteristics of glasses and closest crystalline compounds. The room temperature dc conductivity increases by 7 orders of magnitude with increasing thallium concentration and reaches the value of 10-8 S cm-1 for (Tl2S)50(GeS2)50 sample. Combined with thallium diffusion parameters for (Tl2S)x(GeS)60(GeS2)40-x and (Tl2S)x(GeS)50-x/2(GeS2)50-x/2 composition lines as well as with conductivity characteristics for the crystalline analogues, ionic and electronic conductivities in the (Tl2S)x(GeS2)100-x glasses were estimated separately. The Tl-poor glasses (x ≤ 0.25) are essentially semiconductors, while the Tl-rich vitreous alloys appear to be ionic conductors. The conductivity parameters for (Tl2S)10(GeS)x(GeS2)90-x glasses change non- monotonically with GeS concentration passing by the conductivity minimum for 60% mol. GeS. The same behaviour was observed for thallium free (GeS)x(GeS2)100-x matrix, showing the influence of the GeS/GeS2 ratio on the properties of the thallium-poor semiconducting glasses.
关键词： glass formation,electrical transport,ionic conduction,Thallium thiogermanate glasses
更新于2025-09-23 15:21:01
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New approach to detection of guided waves with negative group velocity: Modeling and experiment
摘要： A new method for detecting the forward and backward acoustic waves in the piezoelectric plates by using a system of the acoustically isolated interdigital transducers (IDT) with the different spatial period is developed. This method was tested on the piezoelectric acoustic modes A1 and SH1 propagating in Y-X LiNbO3 plate. Theoretical analysis has shown that the SH1 mode in the entire frequency range represented a forward wave. At that the dispersion dependence of the A1 mode near the cutoff frequency has a smooth transition from a forward wave to a backward one with decreasing frequency. In order to experimentally observe this transition 19 IDTs with different periods were deposited on a single lithium niobate plate. The measurement of the frequency dependence of the real part of the electrical impedance of these IDTs showed that for SH1 mode the resonance frequency decreased monotonically with a growth in the spatial period. This behavior corresponded to a forward wave. For A1 mode the resonance frequency initially decreased with the growth of the IDT period and then began to increase after reaching a value of ZGV frequency. This behavior is explained by the smooth transition from the region of the forward wave to the region of the backward wave. The calculation of the frequency dependences of the real part of the electrical impedance of each transducer for the waves considered, carried out by the finite element method, turned out to be in good agreement with the experiment.
关键词： interdigital transducer,forward and backward plate acoustic wave,phase and group velocities,dispersion dependencies,finite element analysis,electrical impedance
更新于2025-09-23 15:21:01
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A Predictive Model for the Electrical Transport Within Nanowire Networks
摘要： Thin networks of high aspect ratio conductive nanowires can combine high electrical conductivity with excellent optical transparency, which has led to a widespread use of nanowires in transparent electrodes, transistors, sensors, and ?exible and stretchable conductors. Although the material and application aspects of conductive nanowire ?lms have been thoroughly explored, there is still no model which can relate fundamental physical quantities, like wire resistance, contact resistance and nanowire density, to the sheet resistance of the ?lm. Here we derive an analytical model for the electrical conduction within nanowire networks based on an analysis of the parallel resistor network. The model captures the transport characteristics and ?ts a wide range of experimental data, allowing for the determination of physical parameters and performance limiting factors, in sharp contrast to the commonly employed percolation theory. The model thus constitutes a useful tool with predictive power for the evaluation and optimization of nanowire networks in various applications.
关键词： nanowires,electrical transport,model,percolation,carbon nanotubes,nanowire network,silver nanowires
更新于2025-09-23 15:21:01
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Facile synthesis of La-doped CdS nanoparticles by microwave assisted co-precipitation technique for optoelectronic application
摘要： Low-cost microwave assisted technique has been applied to produce La-doped CdS nanoparticles and their structural, morphological, optical, Raman, dielectric and electrical studies were carried out. Broad XRD peaks revealed the growth of low-dimension La-doped CdS nanoparticles with wurtzite structure. Spherical shape morphology of synthesized nanostructures was confirmed by SEM analysis. SEM mapping and EDAX analysis showed the elemental composition and successful incorporation of La in CdS matrix. Diffused reflectance spectroscopy was used to determine the energy gaps and it was observed to be reduced from 2.47 to 2.3 eV upon La doping. Vibrational studies on La:CdS nanoparticles displayed longitudinal optical modes. PL studies exhibited improved luminescence for the band to band transition of the CdS nanoparticles. The ε’ values are enhanced in general; though it displayed reduced ε’ values at some concentration owing to reduction of polarization. Enhancement in AC conductivity was observed with increasing La concentration and the studies on the involved conduction mechanism revealed that the hopping motion in prepared nanostructures is translation motion with a quick hopping and the behavior is that of ionic conduction.
关键词： FT-Raman spectroscopy,optical properties,dielectric and electrical properties,X-ray diffraction,SEM/EDX,La:CdS
更新于2025-09-23 15:21:01
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Hybrid perovskite light emitting diodes under intense electrical excitation
摘要： Hybrid perovskite semiconductors represent a promising platform for color-tunable light emitting diodes (LEDs) and lasers; however, the behavior of these materials under the intense electrical excitation required for electrically-pumped lasing remains unexplored. Here, we investigate methylammonium lead iodide-based perovskite LEDs under short pulsed drive at current densities up to 620 A cm?2. At low current density (J < 10 A cm?2), we ?nd that the external quantum ef?ciency (EQE) depends strongly on the time-averaged history of the pulse train and show that this curiosity is associated with slow ion movement that changes the internal ?eld distribution and trap density in the device. The impact of ions is less pronounced in the high current density regime (J > 10 A cm?2), where EQE roll-off is dominated by a combination of Joule heating and charge imbalance yet shows no evidence of Auger loss, suggesting that operation at kA cm?2 current densities relevant for a laser diode should be within reach.
关键词： ion movement,electrical excitation,lasers,Auger loss,light emitting diodes,Hybrid perovskite semiconductors,Joule heating,external quantum efficiency,charge imbalance
更新于2025-09-23 15:21:01
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Excellent structural, optical, and electrical properties of Nd-doped BaSnO <sub/>3</sub> transparent thin films
摘要： We epitaxially grew 7 mol. % Nd-doped BaSnO3 (NBSO) thin films on double-side polished SrTiO3 (001) single-crystal substrates and optimized the oxygen pressure (PO2), substrate temperature (TS), and film thickness (t) to achieve excellent structural, optical, and electrical performance. By keeping TS (?800 (cid:2)C) constant, NBSO films prepared at PO2 ? 10 Pa show the best crystallization, yielding a full-width at half-maximum (FWHM) of the x-ray diffraction rocking curve of 0.079(cid:2) and exhibiting a room-temperature resistivity (q) of (cid:3)1.85 mX cm and a volume carrier density (n) of (cid:3)8.5 (cid:4) 1020/cm3. By keeping PO2 (?10 Pa) constant, the room-temperature q of NBSO films could be reduced to as low as 0.5 mX cm by increasing TS from 700 to 825(cid:2); meanwhile, the volume carrier density and mobility show the maximum of 5.04 (cid:4) 1020/cm3 and 24.9 cm2/Vs, respectively, for TS ? 825 (cid:2)C. For all as-grown NBSO thin films, the optical transmittance in the visible wavelength region is larger than 80%. The optimized comprehensive properties of the NBSO films with FWHM ? 0.11(cid:2), q ? 0.5 mX cm, l ? 24.9 cm2/Vs, and T > 80% are superior to those of other rare-earth and 4d- and 5d-transition metal-doped BaSnO3 thin films.
关键词： optical properties,Nd-doped BaSnO3,electrical properties,transparent thin films,structural properties
更新于2025-09-23 15:21:01