Semiconductive Materials Research Articles

Structural deformation of elastic polythiophene with disiloxane moieties under stretching

For the development of wearable and stretchable devices, insights into the mechanical properties and structural deformation of functional conjugated polymers are required. In particular, polythiophene has received much attention as a typical hole transfer material in electronic devices. However, the widely accepted polythiophenes are brittle because of the rigid chemical structure of thiophene rings. We have reported on the synthesis and flexible properties of polythiophene with disiloxane groups in side chains, and it was revealed that the polythiophene exhibited greater than 200% elongation at break at room temperature. In this study, we investigated the deformation process of polythiophene through in situ measurements under stretching using X-ray diffraction of synchrotron radiation and polarized infrared spectroscopy. In the X-ray diffraction measurements, orientation of the crystallites occurred after yielding, while the relative intensities of the polarized infrared absorption bands gradually increased during stretching. As seen from these results, during the initial deformation, the polythiophene chains in the amorphous region were aligned, and then, the whole bulk of the polythiophene, including crystallites and amorphous regions, were oriented after yielding. We succeeded in tracing the structural deformation of polythiophene during stretching. For the development of wearable and stretchable devices, stretchable and flexible semiconductive materials are desired. To understand the mechanical behavior of structural deformation of polythiophene with disiloxane groups, we performed in situ measurements under stretching using X-ray diffraction of synchrotron radiation and polarized infrared spectroscopy. The behaviors of amorphous region was oriented during the initial deformation, while the orientation of crystallites began after permanent set.

Heating behaviour of plasma sprayed TiOx/Cr2O3 coatings for injection moulding

Mould tempering in injection moulding influences part quality as well as process efficiency. Currently established systems are either slow or require an additional process step. A thermally sprayed heating coating on the tool cavity surface enables temperature control in close proximity of the polymer melt.In this study, TiOx/Cr2O3 was used as heating coating covered with a protective coating of Al2O3. The coatings were applied by atmospheric plasma spraying using a three cathode spray gun. The heating behaviour on the surface as well as the phase stability and the thermal durability of the coating system have been investigated. Furthermore, resistance measurements of the TiOx/Cr2O3 coating at different temperatures have been conducted as a negative temperature coefficient in semiconductive materials may enable an additional utilization for precise online process monitoring.

Tailoring the in situ conformation of bacterial cellulose-graphene oxide spherical nanocarriers

Bacterial cellulose (BC)/graphene oxide (GO) sphere-like hydrogels have been biosynthesized by in situ route in dynamic cultivation. The GO concentration during BC biosynthesis (0.01 and 0.05 mg mL−1) was the determining factor for the conformation of the final hydrogels: encapsulation (BC/GO 0.01) or distribution through all the body of the spheres (BC/GO 0.05). The as-prepared sphere hydrogels were characterized in terms of physico-chemical properties, thermal stability, microstructure, and swelling capacity in different media. In addition, a chemical treatment with ascorbic acid was performed in order to obtain reduced graphene oxide (rGO) into the spheres (BC/rGO). After the chemical treatment, electrostatic force microscopy (EFM) revealed electrical interactions due to the presence of rGO inside the spheres and resistivity values in the range of semiconductive materials were obtained (106 Ω·cm), making BC/rGO spheres promising for the development of electro-stimulated systems. The in vitro release study of ibuprofen (IB), showed that the reduction process led to an increase of 73 and 92% of drug release with respect to BC/GO 0.05 and BC/GO 0.01 spheres, respectively. Moreover, the encapsulation conformation showed more homogeneous porous structure and thus, a cumulative drug release of 63% was reached after 6 h.

Two-dimensional d-π conjugated metal-organic framework based on hexahydroxytrinaphthylene

The development of new two-dimensional (2D) d-π conjugated metal-organic frameworks (MOFs) holds great promise for the construction of a new generation of porous and semiconductive materials. This paper describes the synthesis, structural characterization, and electronic properties of a new d-π conjugated 2D MOF based on the use of a new ligand 2,3,8,9,14,15-hexahydroxytrinaphthylene. The reticular self-assembly of this large π-conjugated organic building block with Cu(II) ions in a mixed solvent system of 1,3-dimethyl-2-imidazolidinone (DMI) and H2O with the addition of ammonia water or ethylenediamine leads to a highly crystalline MOF Cu3(HHTN)2, which possesses pore aperture of 2.5 nm. Cu3(HHTN)2 MOF shows moderate electrical conductivity of 9.01 × 10−8 S·cm−1 at 385 K and temperature-dependent band gap ranging from 0.75 to 1.65 eV. After chemical oxidation by I2, the conductivity of Cu3(HHTN)2 can be increased by 360 times. This access to HHTN based MOF adds an important member to previously reported MOF systems with hexagonal lattice, paving the way towards systematic studies of structure-property relationships of semiconductive MOFs.

Synthesis of Al-doped zinc oxide nano particle TCO material by simple Sol-Gel method

Transparent Conducting Oxides (TCOs) are thin films of optically transparent and electrically conductive material. They are an important component in a number of electronic devices including liquid-crystal displays, OLEDs, touchscreens and photovoltaics etc. Indium tin oxide (ITO) is the most widely used TCO but its toxic effect and scarcity in nature causes for high cost of the product and hence technology needs a suitable replacement of it. Out of few replaceable materials, Aluminum doped Zinc Oxide (AZO) semiconductive material has been proven its potential replaceability due to its good transparency in the visible light as well as good conductivity. Also Zinc Oxide is abundant in nature and has no toxic effect. Pure ZnO and AZO sample were synthesized by simple low cost sol gel method and characterized optically and electrically. Effects of Al doping into ZnO nano crystal has been studied on transparency and conductivity aspects. It is observed that in both cases there is an optimum Al atoms concentration governed by the defects introduced by interstitial Al atoms in AZO nano crystal.

Optimization of double-layer stress grading system for high voltage rotating electrical machines by electric field and thermal coupled analysis

Silicon carbide particle-loaded semi-conductive materials with electric field-dependent conductivity have been used for end-turn stress grading (SG) systems of high voltage rotating electrical machines for decades. Particularly, high voltage class turbogenerators use double-layer SG systems, at which two SG materials with different conductivities are applied, to reduce power dissipations within the SG materials. To prevent the excessive local heating of the SG material and resulting flashover, the field-dependent conductivities of the two SG materials, as well as length of the SG layer in the longitudinal direction along a coil, were optimized, by a nonlinear transient electrical field and thermal coupled analysis. The field-dependent conductivities of the SG materials were adjusted to the suitable ones by changing the average diameter of silicon carbide particles. Then, the appropriate length of the SG layer was selected to minimize the temperature rise in the system. As a result, the newly optimized double-layer SG system showed a 20% lower temperature rise, and more than 15% higher flashover voltage than the conventional ones. Therefore, the effectiveness of the optimized double-layer SG system is successfully confirmed.

Development of Statistical Model to Evaluate the Effect of Meteorological Parameters on the Performance of PV-Cell/Module

The growing need for energy by the human society, climate change and depletion of conventional energy sources demands a renewable, safe, illimitable and low-price energy source. One of the best applicable means to break the accountable world’s activity crisis is to use the authority of the sun. Solar activity is clean, great and environment-amicable abeyant ability amid renewable activity options. Solar Photovoltaic (SPV) cells/ modules are composed of silicon or other semi-conductive materials. Semiconductor materials have negative temperature coefficient. The photovoltaic module power output/efficiency depends linearly on the operating temperature while operating temperature of photovoltaic module is depends on the meteorological parameters such as: wind speed, humidity, sky condition etc. In order to predict the energy production of photovoltaic (PV) modules, it’s far compulsory to presage the PV module temperature as a function of ambient temperature, wind speed, wind direction, total irradiance, and relative humidity. This paper presents a statistical model to evaluate the effect of meteorological parameters on the performance of PV cell/module and predict the modules efficiency & module temperature. How to cite this article: Sanjay, Berwal AK. Development of Statistical Model to Evaluate the Effect of Meteorological Parameters on the Performance of PV-Cell/ Module. J Adv Res Alt Energ Env Eco 2020; 7(1): 1-7. DOI: https://doi.org/10.24321/2455.3093.202001

Syntheses, Crystal Structures, Characterization, Optical Band Gaps and Photoluminescence of Two Zn(II) Coordination Polymers

Two novel coordination polymers based on Zn(II) ions, 1-((1H-1,2,4-triazol-1-yl)methyl)-3-(4-pyridyl)-5-(3-pyridyl)-1,2,4-triazole (3,4′-tmbpt), and two aromatic polycarboxylate anions, namely [Zn(3,4′-tmbpt)(m-bdc)(H2O)]·H2O (1) and [Zn2(3,4′-tmbpt)(btc)(OH)] (2) (m-H2bdc = 1,3-benzenedicarboxylic acid and H3btc = 1,3,5-benzenetricarboxylic acid), have been synthesized. The structures of 1 and 2 have been characterized by single-crystal X-ray diffraction analyses, elemental analyses, infrared spectra, powder X-ray diffraction analyses and thermogravimetric analyses. Compound 1 shows a 2D layered structure, which is extended by the hydrogen bonding interactions to form a 3D supramolecular architecture. Compound 2 exhibits a 3D twofold interpenetrating framework with a Schlafli symbol of (63)(69·8). Diffuse reflection spectra of 1 and 2 indicate that the band gaps of 1 and 2 are 3.42 and 3.63 eV, respectively. The results indicate that compounds 1 and 2 may be potential semiconductive materials with wide band gaps. Moreover, 1 and 2 display intense blue-green emission and appear to be potential photoactive materials. Two new coordination polymers based on a multidentate N-donor ligand, Zn(II) ions, and two aromatic polycarboxylate anions have been synthesized and characterized. The optical band gaps and photoluminescent spectra of the compounds have been investigated.

Effect of Ionic Conductors on the Suppression of PTC and Carrier Emission of Semiconductive Composites

The positive temperature coefficient (PTC) effect of the semiconductive layers of high-voltage direct current (HVDC) cables is a key factor limiting its usage when the temperature exceeds 70 °C. The conductivity of the ionic conductor increases with the increase in temperature. Based on the characteristics of the ionic conductor, the PTC effect of the composite can be weakened by doping the ionic conductor into the semiconductive materials. Thus, in this paper, the PCT effects of electrical resistivity in perovskite La0.6Sr0.4CoO3 (LSC) particle-dispersed semiconductive composites are discussed based on experimental results from scanning electron microscopy (SEM), transmission electron microscopy (TEM) and a semiconductive resistance test device. Semiconductive composites with different LSC contents of 0.5 wt%, 1 wt%, 3 wt%, and 5 wt% were prepared by hot pressing crosslinking. The results show that the PTC effect is weakened due to the addition of LSC. At the same time, the injection of space charge in the insulating sample is characterized by the pulsed electroacoustic method (PEA) and the thermally stimulated current method (TSC), and the results show that when the content of LSC is 1 wt%, the injection of space charge in the insulating layer can be significantly reduced.

Synthesis of a Novel Semi-Conductive Composites Doping with La0.8Sr0.2MnO3 for Excellent Electric Performance for HVDC Cable.

The semi-conductive layer located between the wire core and the insulation layer in high voltage direct current (HVDC) cable plays a vital role in uniform electric field and affecting space charges behaviors. In this work, the research idea of adding ionic conductive particles to semi-conductive materials to improve the conductive network and reduce the energy of the moving charge inside it and to suppress charge injection was proposed. Semi-conductive composites doped with different La0.8Sr0.2MnO3 (LSM) contents were prepared. Resistivity at different temperatures was measured to investigate the positive temperature coefficient (PTC) effect. Pulse electro-acoustic (PEA) method and thermal-stimulation depolarization currents (TSDC) tests of the insulation layers were carried out. From the results, space charge distribution and TSDC currents in the insulation samples were analyzed to evaluate the inhibitory effect on space charge injection. When LSM content is 6 wt. %, the experimental results show that the PTC effect of the specimen and charge injection are both being suppressed significantly. The maximum resistivity of it is decreased by 53.3% and the insulation sample has the smallest charge amount, 1.85 × 10−7 C under 10 kV/mm—decreased by 40%, 3.6 × 10−7 C under 20 kV/mm—decreased by 45%, and 6.42 × 10−7 C under 30 kV/mm—decreased by 26%. When the LSM content reaches 10 wt. %, the suppression effect on the PTC effect and the charge injection are both weakened, owing to the agglomeration of the conductive particles inside the composites which leads to the interface electric field distortion and results in charge injection enhancement.

InVivo Bioengineering of Fluorescent Conductive Protein-Dye Microfibers.

SummaryEngineering protein-based biomaterials is extremely challenging in bioelectronics, medicine, and materials science, as mechanical, electrical, and optical properties need to be merged to biocompatibility and resistance to biodegradation. An effective strategy is the engineering of physiological processes in situ, by addition of new properties to endogenous components. Here we show that a green fluorescent semiconducting thiophene dye, DTTO, promotes, in vivo, the biogenesis of fluorescent conductive protein microfibers via metabolic pathways. By challenging the simple freshwater polyp Hydra vulgaris with DTTO, we demonstrate the stable incorporation of the dye into supramolecular protein-dye co-assembled microfibers without signs of toxicity. An integrated multilevel analysis including morphological, optical, spectroscopical, and electrical characterization shows electrical conductivity of biofibers, opening the door to new opportunities for augmenting electronic functionalities within living tissue, which may be exploited for the regulation of cell and animal physiology, or in pathological contexts to enhance bioelectrical signaling.

Efficient Visible-Light-Driven CO2 Reduction by a Cobalt Molecular Catalyst Covalently Linked to Mesoporous Carbon Nitride.

Achieving visible-light-driven carbon dioxide reduction with high selectivity control and durability while using only earth abundant elements requires new strategies. Hybrid catalytic material was prepared upon covalent grafting a Co-quaterpyridine molecular complex to semiconductive mesoporous graphitic carbon nitride (mpg-C3N4) through an amide linkage. The molecular material was characterized by various spectroscopic techniques, including XPS, IR, and impedance spectroscopy. It proved to be a selective catalyst for CO production in acetonitrile using a solar simulator with a high 98% selectivity, while being remarkably robust since no degradation was observed after 4 days of irradiation (ca. 500 catalytic cycles). This unique combination of a selective molecular catalyst with a simple and robust semiconductive material opens new pathways for CO2 catalytic light-driven reduction.

Additively Manufactured RF Devices for 5G, IoT, RFID, WSN, and Smart City Applications

With the development of inkjet-/3D-/4D-printing additive manufacturing technologies, flexible 3D substrate with complex structures can be patterned with dielectric, conductive and semi-conductive materials to realize novel RF designs. This paper provides a review of state-of-the-art additively manufactured passive RF devices including antennas and frequency selective surfaces (FSS), couplers, where origami-inspired structure enables unprecedented capabilities of on-demand continuous frequency tunability and deployability. This paper also discusses additively manufactured active RF modules and systems such as inkjet printed RF energy harvester system with high sensitivity and efficiency for Internet of Things (IoT), smart cities and wireless sensor networks (WSN) applications, inkjet-printed RF front ends, and inkjet-printed mm-wave backscatter modules.

РОЗРОБКА АНТИСТАТИЧНИХ І НАПІВПРОВІДНИКОВИХ КОМПОЗИЦІЙ ПОЛІЕТИЛЕН/ПОЛІАНІЛІН ТА ПОЛІВІНІЛХЛОРИД/ПОЛІАНІЛІН

The effect of the polyaniline content on the mechanical, rheological and electrical properties of polyethylene and polyvinylchloride compositions for the production of antistatic and semiconductive materials was established. Samples of polymer composites were obtained in two stages: 1) mixing of components in a mixer type "disk in disk"; 2) pressing into films by the method of "hot pressing." Tensile strength, relative elongation, melt flow index and specific volume electrical resistance of the compositions were investigated by standard methods. It was found that an increase in the volume content of polyaniline in the polyethylene and polyvinylchloride matrix leads to a monotonic decrease in the melt flow index, as well as tensile strength and relative elongation. At the same time, there is a significant decrease in the specific volume electrical resistance in polyethylene and polyvinylchloride composite films, which contain up to 30% vol. of polyaniline. The reduction of the tensile strength and the relative elongation of films from compositions containing up to 30% vol. of polyaniline. This is due to the decrease in the viscosity of the melt-filled compositions, as evidenced by the decrease in the flow index of the melt polyethylene compositions from 3 to 2 g / 10 min, and polyvinylchloride – from 13 to 3 g / 10 min. Specific volume electrical resistance naturally decreases with increasing volume concentration of the filler in ranges from 1014 to 102 Ohm ∙ m for polyethylene compositions and from 1010 to 101 Ohm ∙ m for polyvinylchloride compositions. The developed polyethylene and polyvinylchloride compositions filled with polyaniline can be used for the production of polymer products with antistatic and semiconductive properties.

Thiophene-Based Aldehyde Derivatives for Functionalizable and Adhesive Semiconducting Polymers.

The pursuit for novelty in the field of (bio)electronics demands for new and better-performing (semi)conductive materials. Since the discovery of poly(3,4-ethylenedioxythiophene) (PEDOT), the ubiquitous golden standard, many studies have focused on its applications but only few on its structural modification and/or functionalization. This lack of structural variety strongly limits the versatility of PEDOT, thus hampering the development of novel PEDOT-based materials. In this paper, we present a short and simple strategy for introducing an aldehyde functionality in thiophene-based semiconducting polymers. First, through a two-step synthesis, an EDOT-aldehyde derivative was prepared and polymerized, both chemically and electrochemically. Next, to overcome the inability of thiophene-aldehyde to be polymerized by any means, we synthesized a trimer in which thiophene-aldehyde is enclosed between two EDOT groups. The successful chemical and electrochemical polymerization of this new trimer is presented. The polymer suspensions were characterized by ultraviolet-visible-near-infrared spectroscopy, while the corresponding films were characterized by Fourier transform infrared and four-point-probe conductivity measurements. Afterward, insoluble semiconducting films were formed by using ethylenediamine as a cross-linker, demonstrating in this way the suitability of the aldehyde group for the easy chemical modification of our material. The efficient reactivity conferred by aldehyde groups was also exploited for grafting fluorescent polyamine nanoparticles on the film surface, creating a fluorescent semiconducting polymer film. The films prepared by electropolymerization, as shown by means of a sonication test, exhibit strong surface adhesion on pristine indium tin oxide (ITO). This property paves the way for the application of these polymers as conductive electrodes for interfacing with living organisms. Thanks to the high reactivity of the aldehyde group, the aldehyde-bearing thiophene-based polymers prepared herein are extremely valuable for numerous applications requiring the facile incorporation of a functional group on thiophene, such as the functionalization with labile molecules (thermo-, photo-, and electro-labile, pH sensitive, etc.).

Research progress of semiconductive shielding layer of HVDC cable

As an indispensable part of high-voltage direct current (HVDC) cable, the semiconductive shielding layer plays the role of uniforming electric field in the cable. However, cable shielding materials >35 kV mainly rely on foreign imports in China, which belongs to the technical weak issues in the field of electrical materials. At present, there are few systematic reports on semiconductive shielding material of HVDC cable. In the work, the mechanisms of charge conduction and thermal conduction of semiconductive material have been introduced. Effect of raw material, carbon black content and the second conductive filler on the resistance characteristics of the semiconductive layer, the charge accumulation characteristics of the insulating layer and the interface characteristics have been studied. A kind of semiconductive layer as a high voltage terminal charge emission method has been proposed to study charge emission from the semiconducting layer to the insulation layer. This work can provide theoretical guidance for the research of semiconductive shielding materials.

Molecular catalysis of CO2 reduction: recent advances and perspectives in electrochemical and light-driven processes with selected Fe, Ni and Co aza macrocyclic and polypyridine complexes.

Earth-abundant Fe, Ni, and Co aza macrocyclic and polypyridine complexes have been thoroughly investigated for CO2 electrochemical and visible-light-driven reduction. Since the first reports in the 1970s, an enormous body of work has been accumulated regarding the two-electron two-proton reduction of the gas, along with mechanistic and spectroscopic efforts to rationalize the reactivity and establish guidelines for structure-reactivity relationships. The ability to fine tune the ligand structure and the almost unlimited possibilities of designing new complexes have led to highly selective and efficient catalysts. Recent efforts toward developing hybrid systems upon combining molecular catalysts with conductive or semi-conductive materials have converged to high catalytic performances in water solutions, to the inclusion of these catalysts into CO2 electrolyzers and photo-electrochemical devices, and to the discovery of catalytic pathways beyond two electrons. Combined with the continuous mechanistic efforts and new developments for in situ and in operando spectroscopic studies, molecular catalysis of CO2 reduction remains a highly creative approach.

Nonlinear Switching Transient Field Simulation of Cable Joint without Residual Charge

The analysis of the impulse voltage on the internal electric field of the cable joint plays a key role in studying the breakdown of the joint. Based on the finite element method, a three-dimensional electromagnetic field simulation model of the cable joint is established in this paper. Simulation results show that the voltage at the head of the cable joint reaches about twice the impulse voltage. The increase of the conductivity of semi-conductive material also leads to the increase of electric field intensity. Then, several points and curves at different positions are selected for further analysis in this paper. Among them, the electric field distortion at the edge of the high voltage shield is the most serious and the electric field in the air gap is the least.

Influence of sonication time on the structure and electrical properties of Na2Ti6O13 ceramics: An approach applying the Mott-Schottky model

In the past years, semiconductive sodium titanate material has been widely studied due to its diverse applications and advantageous physico - chemical properties. In this direction, the present work reports the effect of sonication time on the structural and electrical properties of sodium titanate (Na2Ti6O13) ceramics. In addition, Mott-Schottky model is used to reveal the semiconductive characteristics of the Na2Ti6O13 ceramic samples.The samples are produced by sonochemical route, using sonication times of 15 and 60 min. X-ray diffraction analyses of the samples determine the presence of a single phase, corresponding to the monoclinic Na2Ti6O13 phase. Crystallites size, calculated by the Scherrer method, are 44.83 (55) nm and 39.45 (69) nm for 15 and 60 min sonicated samples, respectively. The electrical characterization of these samples, performed by Complex Impedance Spectroscopy, reveals a decrease in resistivity with increasing sonication time; while the Mott-Schottky model provides information about the semiconductive behavior of the samples. Flat band potential of 1.1 V and 0.92 V and charge carrier densities of 1.09 × 1013 cm−3 and 0.92 × 1013 cm−3 are determined for those samples.

The influence mechanism of semiconductive material on space charge accumulation in HVDC cable accessory

To study the effect of semiconductive (SC) material on space charge accumulation in cable accessories, an accelerated aging of cable samples with cable accessories was carried out in the laboratory. The experimental results show accumulation of space charge in the cable insulation covered by a stress cone, whereas the space charge was negligible in the region wrapped by the accessory-reinforced insulation as well as regions not in contact with the accessory. With increased aging time, the space charge density gradually increased, and the axial distribution gradually extended. A comparative experiment on cable insulation slices was carried out using silicone rubber and EVA SC material as the upper electrodes to determine the cause of the space charge accumulation. The results showed that a large quantity of heteropolar charges accumulated near the silicone rubber SC upper electrode, whereas the charges near the EVA SC electrode were negligible. It was concluded that due to the weak charge conducting ability of the silicone rubber SC material used as the electrode, space charges cannot escape from the stress cone and thus accumulate on the outside of the cable insulation at the stress cone position. This paper shows that the SC material used in cable accessories plays an important role in space charge accumulation.