Results 1 - 10 of 42
Results 1 - 10 of 42. Search took: 0.018 seconds
|Sort by: date | relevance|
[en] Nd7Fe67B22Mo3Zr1 magnets in rods have been prepared by annealing the amorphous precursors produced through injection casting. Phase formation, microstructure and magnetic properties of Nd7Fe67B22Mo3Zr1 magnets have been investigated and discussed in the as-cast and annealed states. Cast Nd7Fe67B22Mo3Zr1 rods have the soft magnetic characteristics, which changed into magnetically hard by annealing. Magnetic properties in Nd7Fe67B22Mo3Zr1 magnets are influenced by the intrinsic properties of magnetically soft α-Fe (Fe3B) and hard Nd2Fe14B phases. The Zr and Mo elements in the Nd7Fe67B22Mo3Zr1 alloy promote the formation of amorphous phase and reduce the grain size of magnetic phases. Optimal annealed Nd7Fe67B22Mo3Zr1 rods of 2 mm in diameter and 52 mm in length presented maximum magnetic properties such as: remanence (Br) of 0.53 T, coercivity (iHc) of 1110 kA/m and maximum energy product (BH)max of 49.5 kJ/m3. - Highlights: • Nd7Fe67B22Mo3Zr1 amorphous rods were synthesized by injection casting. • Nanocomposite magnets were obtained after annealing the amorphous precursors. • Magnetic properties arise from magnetically exchanged coupled soft and hard phases
[en] The next generation technologies based on perovskite solar cells (PSCs) are targeted to develop a true low cost, low tech, widely deployable, easily manufactured and reliable photovoltaics. After the extremely fast evolution in the last few years on the laboratory-scale, PSCs power conversion efficiency (PCE) reached over 24%. However, the widespread use of PSCs requires addressing the stability and industrial scale production issues. Carbon based monolithic perovskite solar cells (mPSCs) are one of the most promising candidates for the commercialization of the PSCs. mPSCs possess a unique architectural design and pave an easy way to produce large area and cost-effective fabrication of the PSCs. In this article, recent progress in the field of mPSCs, challenges and strategies for their improvement are briefly reviewed. Also, we focus on the predominant implementations of recent techniques in the fabrication of the mPSCs to improve their performance. This review is intended to serve as a future direction guide for the scientists who are looking forward to developing more reliable, cost-effective and large area PSCs.
[en] Nylon 6,6 polymer and cobalt–manganese oxide nanoparticles (Co–Mn NPs)/nylon 6,6 nanocomposites were prepared by solution casting method. The morphological study illustrated that the Co–Mn NPs were well dispersed within the membrane. The differential scanning calorimetry (DSC) analyses presented that the melting temperature (Tm) and crystallization temperature (Tc) of Co–Mn NPs/nylon 6,6 membranes were higher than neat nylon 6,6, while the mechanical properties of nanocomposite membranes were lower than neat nylon 6,6. The nanocomposite and neat nylon 6,6 membranes were also used for the decolorization of alizarin red dye in an aqueous medium as a function of time. It was found that about 70–83% of dye was decolorized within 150 min using nanocomposite membranes.
[en] An investigation has been made on the properties of an impedance hygrometer fabricated using cellulose and copper phthalocyanine (Ag/cellulose/CuPc/Ag). A 5wt% suspension of cellulose was prepared in water while the CuPc was dissolved in methanol. Cellulose film was deposited on glass substrates with preliminary deposited metallic electrodes followed by deposition of CuPc film. The resistances and capacitances of the samples were evaluated under the effect of humidity. The impedance was calculated from resistance and capacitance measurements. It was also measured during the experiment. It was observed that the capacitance of the sensor increases and resistance and impedance decrease with an increase in the relative humidity level. It was found that the impedance-humidity relationship showed more uniform changes in the interval of 31%-98% RH than the resistance- and capacitance-humidity relationships that showed visible changes in the humidity intervals of 31%-80% RH and 80%-98% RH respectively. The humidity-dependent impedance of the sample makes it attractive for use in impedance hygrometers. The impedance hygrometer may be used in instruments for the environmental monitoring of humidity. (semiconductor devices)
[en] A hetero-junction of n-silicon (n-Si) and copper phthalocyanine (CuPc) has been fabricated. The current-voltage characteristics were investigated to explain the rectification and conduction mechanism. The effect of temperature and humidity on the electrical properties of n-Si/CuPc hetero-junction has also been investigated. The characteristics of the junction have been observed to be temperature and humidity dependent, so it is suggested that this junction can be used as a temperature and humidity sensor.
[en] We demonstrate the effects of solvent treatment on the optical band gap and surface morphology of nickel (ii) phthalocyanine tetrasulfonic acid tetrasodium salt (NiTsPc) thin films. The optical band gap and surface morphology modifications are carried out by immersing the films in chloroform for different immersion times until the optimized time (60 min) is found. A Tauc plot is used to calculate the optical energy gaps, which are found to be about 2.70–2.85 eV and 1.43–1.50 eV, in the B and Q bands respectively. AFM topography shows that more granular structures have been formed upon the optimized immersion time. Photoluminescence (PL) quenching occurs in the solvent-treated NiTsPc film incorporated with a tris(8-hydroxyquinolinato)aluminium (Alq3) layer. This PL quenching indicates that the charge carrier transport is more efficient at the interface between NiTsPc/Alq3 as a result of the solvent treatment
[en] The blend of nickel phthalocyanine (NiPc) (2 wt. %) poly-N-epoxypropylcarbazole (PEPC), (1 wt. %) and carbon nano-tube (CNT) powder (2 wt. %) in benzole is deposited by drop-casting on glass substrates with pre-deposited metallic electrodes to fabricate Ag/CNT/NiPc/PEPC/A1 surface type cell. It is assumed that the high nonlinearity of the I — V characteristics is related to deep traps in the nano-scale depletion region in NiPc that is observed experimentally. The values of ideality factor and barrier height are determined from the I — V curve and they are found to be 8.4 and 1.05eV, respectively. The values of mobility and conductivity are calculated to be 7.94 × 10−8 cm/Vs and 3.5 × 10−6 Ω−1 cm−1. The values of ideality factor and series resistance are also calculated by using Cheung's functions, which are in good agreement with the values calculated from the I — V curve
[en] This study presents the fabrication and characterization of novel surface-type capacitive humidity sensors using vanadyl phthalocyanine (VOPc) as the active material. The devices, which comprise three different thicknesses, have been fabricated using the thermal evaporation technique. A thin film of VOPc is deposited on thoroughly cleaned glass substrates with pre-patterned Ag electrodes. The capacitive effect of the samples under humidity has been investigated. Comparison of the samples with different thicknesses shows that the thinnest device seems more sensitive towards humidity. The humidity dependent capacitance properties of the sensor make it beneficial for use in commercial hygrometers.
[en] In this research, we report a bulk heterojunction (BHJ) solar cell consisting of a ternary blend system. Poly(3-hexylthiophene) P3HT is used as a donor and [6,6]-phenyl C61-butyric acid methylester (PCBM) plays the role of acceptor whereas vanadyl 2,9,16,23-tetraphenoxy-29H, 31H-phthalocyanine (VOPcPhO) is selected as an ambipolar transport material. The materials are selected and assembled in such a fashion that the generated charge carriers could efficiently be transported rightwards within the blend. The organic BHJ solar cells consist of ITO/PEDOT:PSS/ternary BHJ blend/Al structure. The power conversion efficiencies of the ITO/ PEDOT:PSS/P3HT:PCBM/Al and ITO/PEDOT:PSS/ P3HT:PCBM:VOPcPhO/Al solar cells are found to be 2.3% and 3.4%, respectively. (paper)
[en] In this paper, the fabrication and investigation of flexible impedance and capacitive tensile load sensors based on carbon nanotube (CNT) composite are reported. On thin rubber substrates, CNTs are deposited from suspension in water and pressed at elevated temperature. It is found that the fabricated load cells are highly sensitive to the applied mechanical force with good repeatability. The increase in impedance of the cells is observed to be 2.0 times while the decrease in the capacitance is found to be 2.1 times as applied force increases up to 0.3 N. The average impedance and capacitive sensitivity of the cell are equal to 3.4 N"−"1 and 1.8 N"−"1, respectively. Experimental results are compared with the simulated values, and they show that they are in reasonable agreement with each other. (paper)