Showing papers in "Journal of Electronic Materials in 2021"
TL;DR: The dye-sensitized solar cell (DSSC) has immense capacity to satisfy the energy demands of most indoor electronics, making it a very attractive power candidates because of its many benefits such as readily available materials, relatively cheap manufacturing methods and roll-to-roll compatibility as discussed by the authors.
Abstract: Lightweight computing technologies such as the Internet of Things and flexible wearable systems have penetrated our everyday lives exponentially in recent years Without a question, the running of such electronic devices is a major energy problem Generally, these devices need power within the range of microwatts and operate mostly indoors Thus, it is appropriate to have a self-sustainable power source, such as the photovoltaic (PV) cell, which can harvest indoor light Among other PV cells, the dye-sensitized solar cell (DSSC) has immense capacity to satisfy the energy demands of most indoor electronics, making it a very attractive power candidates because of its many benefits such as readily available materials, relatively cheap manufacturing methods, roll-to-roll compatibility, easy processing capabilities on flexible substrates and exceptional diffuse/low-light performance This review discusses the recent developments in DSSC materials for its indoor applications Ultimately, the perspective on this topic is presented after summing up the current progress of the research
58 citations
TL;DR: A modest electrochemically polymerised glutamic acid layered multi-walled carbon nanotube paste electrode [P(GA)LMWCNTPE] was functionalised for the sensing of indigo carmine (IC) by powerful differential pulse voltammetry (DPV) and cyclic voltammetric (CV) approaches as mentioned in this paper.
Abstract: Some colourants are hazardous to living species; hence, a powerful and fast methodology is required for the analysis of those colourants in food and water samples. A modest electrochemically polymerised glutamic acid layered multi-walled carbon nanotube paste electrode [P(GA)LMWCNTPE] was functionalised for the sensing of indigo carmine (IC) by powerful differential pulse voltammetry (DPV) and cyclic voltammetry (CV) approaches. Within the optimised experimental conditions, the P(GA)LMWCNTPE holds an acceptable and high rate of electro-catalytic activity towards the redox behaviour of IC. The projected P(GA)LMWCNTPE shows a decent selectivity for IC in the presence of methyl orange. The modified sensor shows an acceptable linear growth between oxidative peak current and concentration in both CV and DPV methods with fine limit of detection values of 4.2 µM and 0.36 µM, respectively. Additionally, the developed sensor was effectively applied to detect IC in food and water samples. The morphological and surface activities of the modified and unmodified electrodes were determined through field emission scanning electron microscopy, electrochemical impedance spectroscopy, and CV techniques. The P(GA)LMWCNTPE requires a simple preparation procedure and is low-cost, with acceptable storage stability, sensitivity, and reproducibility.
39 citations
TL;DR: In this article, the melting-quenching technique has been used to manufacture glasses in the P2O5-25Li2O-5Al2O3-676 TiO2 system.
Abstract: The melt-quenching technique has been used to manufacture glasses in the $$(70-x)$$
P2O5-25Li2O-5Al2O3-
$$x$$
TiO2 $$(0\le x \ge 25)$$
system. XRD analysis was applied to examine the crystalline nature of the samples. The absorbance and reflectance were measured and the optical characteristics determined for the prepared glasses at room temperature. Nonbridging oxygen creation was observed, being due to the increase in the concentration of titanium oxide. Therefore, a reduction of the refractive index and energy gap of these glasses was recorded. The polarizability and basicity of the glasses were calculated from the refractive index and bandgap measurement results, revealing the same behavior as observed for the refractive index. The dispersion relationships are applied to evaluate the influence of titanium oxide on these parameters.
37 citations
TL;DR: In this article, a ternary 5%CuS/(1%Ag/BTO) composite was constructed by anchoring CuS and Ag nanoparticles onto BaTiO3 polyhedra.
Abstract: Herein, binary CuS/BTO and ternary CuS/Ag/BTO composite photocatalysts have been fabricated by anchoring CuS and Ag nanoparticles onto BaTiO3 (BTO) polyhedra. The as-prepared composite photocatalysts were characterized by means of the techniques of transmission/scanning electron microscopy, x-ray powder diffraction, ultraviolet–visible diffuse reflectance spectroscopy, x-ray photoelectron spectroscopy and photoluminescence spectroscopy. Transient photocurrent and electrochemical impedance spectroscopy measurements suggest that the ternary 5%CuS/(1%Ag/BTO) composite possesses the highest separation efficiency of electron/hole pairs. The photodegradation experiments were conducted by using simulated sunlight as the light source to decompose Rhodamine B in water solution. The 5%CuS/(1%Ag/BTO) and 5%CuS/BTO composites are demonstrated to have the highest and second highest photodegradation activity, respectively. As compared with that of bare BaTiO3 and CuS, the photoactivity of 5%CuS/(1%Ag/BTO) is increased to 3.3 and 2.0 times, respectively. The electron/hole separation mechanism and the role of localized surface plasmon resonance of Ag nanoparticles in the dye photodegradaton were systematically investigated.
37 citations
TL;DR: In this paper, a MXene/cellulose nanofiber composite film with low density and high conductivity was prepared by using an ice crystal sacrificial template as a pore-forming agent and CNF as a structural reinforcement.
Abstract: Lightweight and high-strength materials with high electromagnetic interference shielding performance are the best solution for electromagnetic pollution. However, the MXene film with extremely high electromagnetic interference shielding effectiveness cannot be extensively applied to the aerospace engineering because of its high density and low mechanical properties. Herein, a MXene/cellulose nanofiber (CNF) composite film with low density and high conductivity (24,875 S m−1) was prepared by using an ice crystal sacrificial template as a pore-forming agent and CNF as a structural reinforcement. The composite film with a small thickness effectively shielded electromagnetic waves since it has a continuous three-dimensional MXene conductive network framework, which serves as a rich interface to facilitate multiple reflections and absorption attenuation of electromagnetic waves. In addition, the absolute electromagnetic interference shielding effectiveness of the prepared film reached 9177 dB cm2 g−1. The design concept and approaches adopted in this work are highly efficient and scalable, which provides a bright prospect for the development of the MXene/polymer composites with high electromagnetic interference shielding properties.
34 citations
TL;DR: In this paper, the development of nanomaterial-based gas sensors has led to demanding research interest in the last few decades due to their potential for high sensitivity, selectivity, and fast detection of various environmentally hazardous gases.
Abstract: The development of nanomaterial-based gas sensors has led to demanding research interest in the last few decades due to their potential for high sensitivity, selectivity, and fast detection of various environmentally hazardous gases. Hydrogen sulfide (H2S) is a hazardous gas normally produced from sewage, mines, petroleum fields, gasoline, natural gas production, etc. In this review, advancements in the development of different metal-oxide semiconductors (MOS) and carbon-based H2S gas sensors are summarised. The commonly investigated materials in MOS are zinc oxide, tin oxide, tungsten oxide, titanium oxide, indium oxide, copper oxide, and composites, and in carbon allotropes, graphene, carbon nanotubes, and fullerene have been tested for H2S gas sensing. The main focus of this review is the description of the various synthesis processes and the morphology of H2S gas sensors by various researchers in order to improve the sensing performance parameters, such as response, sensitivity, selectivity, response time, and recovery time using different materials/catalysts.
24 citations
TL;DR: In this article, elpasolite perovskites, Cs2NaMCl6 (M = In, Tl, Sb, Bi), are investigated using density functional theory.
Abstract: In this article, elpasolite perovskites, Cs2NaMCl6 (M = In, Tl, Sb, Bi), are investigated using density functional theory (DFT). Structural properties like lattice constants and bond lengths are in agreement with the available experimental data. Electronic properties are calculated by several DFT exchange-correlation approximations, and it is found that a modified Becke–Johnson (mBJ) approximation along with the inclusion of spin orbit coupling (SOC) gives the most promising results. The M-site cation decides the nature of the band gap; i.e. direct band gaps are obtained for group IIIA elements (In, Tl), and indirect band gaps are experiential for group VA elements (Sb, Bi). Narrow discrete energy bands are observed in the valence and conduction bands, which make these compounds suitable for scintillation applications. SOC induces splitting of Bi/Sb p orbitals in the conduction band and reduces the band gaps of these double perovskite halides. Obtained values of mechanical parameters confirm that these compounds are ductile and anisotropic. Optical properties, i.e. dielectric functions, energy loss function and refractive index, are also calculated, and interesting variations are found which can play a important role in scintillation and other optoelectronic applications of these materials.
23 citations
TL;DR: In this paper, the structural, morphological, magnetic and DC electrical resistivity properties of the prepared samples were analyzed using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) with EDS, Fourier transform infrared (FTIR) spectroscopy, vibrating sample magnetometry (VSM), and two-probe methods.
Abstract: Cu-doped Co–Zn nanoferrites Co0.5CuxZn0.5 − xFe2O4 (x = 0.0, 0.2 and 0.4) were synthesized by sol-gel auto-combustion. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) with EDS, Fourier transform infrared (FTIR) spectroscopy, vibrating sample magnetometry (VSM), and two-probe methods were employed to study the structural, morphological, magnetic and DC electrical resistivity properties, respectively, of the prepared samples. Monotonically decreasing values of the lattice constants with the dopant concentrations were calculated. The crystallite sizes were also recorded in a decreasing pattern. The stretching bond vibrations measured by room temperature FT-IR showed characteristic absorptions in the range of 579.634–393.49 cm − 1. The magnetic parameters were observed to have a tuned value, although decreasing in a non-monotonic pattern. A higher value of the DC resistivity value was recorded for x = 0.2 concentration of the dopant, indicating the optimal concentration for synthesizing materials applicable in high-frequency microwave devices.
23 citations
TL;DR: In this article, a first-principles investigation is carried out on palladium-doped armchair graphene nanoribbons (AGNRs) to investigate their structural, electronic and transport properties.
Abstract: A first-principles investigation is carried out on palladium (Pd)-doped armchair graphene nanoribbons (AGNRs) to investigate their structural, electronic and transport properties. The structural analysis of the considered Pd-doped nanoribbons reveals that single Pd doping at the edges of AGNRs results in the most stable configuration. The present findings reveal that the electronic transport properties are strongly dependent on the number of dopant atoms and their positions. Furthermore, it is noted that the proposed two-probe devices exhibit peculiar nonlinear I–V characteristics indicating potential for rectification behavior. Excellent high rectification ratio (RR) and reverse rectification ratio (RRR) are on the order of $$1.8\times 10^{5}$$
and $$9.7\times 10^{4}$$
, respectively, are found for center-Pd-doped 7-AGNRs. The interesting rectifying I–V behavior can be explained by the localization/delocalization effect of frontier orbitals along with the variation of the transmission spectra with the applied bias voltage. These findings indicate that Pd-doped armchair GNRs are a potential candidate for use in next-generation ultralow-power nanoscale switching devices.
23 citations
TL;DR: In this article, Ni and Coincorporated CH3NH3PbI3 perovskite solar cells were fabricated and characterized to optimize the photovoltaic and optical properties related to surface morphology, crystal growth and orientation, and electronic structures.
Abstract: Ni- and Co-incorporated CH3NH3PbI3 perovskite solar cells were fabricated and characterized to optimize the photovoltaic and optical properties related to surface morphology, crystal growth and orientation, and electronic structures. Partially replacing Pb with Ni or Co in the perovskite crystals improved the photovoltaic performance and carrier mobility based on the effective mass in the band structure. In particular, the addition of both Ni and Rb compounds to perovskite improved the long-term stability of the photovoltaic cells, which depended on surface modification and coverage, crystal growth, and the high (100) orientation in the perovskite layer. The short-circuit current density of the cells was increased by promoting the generation and mobility of photoinduced carriers, which were inversely proportional to the effective mass ratio. Electron correlation was associated with the promotion of charge transfer owing to the hybridization between the 3d orbitals of Ni and the 5p orbitals of the I atoms near the valence band state.
22 citations
TL;DR: In this article, the lifetime prediction of a SiC power module by Ag sinter joining based on mechanical properties including tensile, fatigue, and creep properties from room temperature to 200°C, as well as thermal properties including thermal conduction and the coefficient of thermal expansion were evaluated.
Abstract: Ag sinter joining technology has gained increasing attention for its excellent thermal and mechanical properties, especially for high-temperature applications. This study focuses on the lifetime prediction of a SiC power module by Ag sinter joining based on mechanical properties including tensile, fatigue, and creep properties from room temperature to 200°C, as well as thermal properties including thermal conduction and the coefficient of thermal expansion. These mechanical properties and thermal properties of sintered Ag paste were evaluated in the study and the results show that mechanical properties of sintered Ag largely depend on the test temperature. The sintered Ag paste tends to soften at high temperature, and the fracture changed from nearly brittle to totally ductile with the testing temperature increase. From the S–N curve, the fatigue is close to the Morrow equation but not the Coffin–Manson law at room temperature. The finite element simulation of the lifetime based on Morrow’s equation for the sintered Ag layer shows that there has a crack occurrence with one fourth the side length after 10,000 cycles from − 40°C to 200°C but the crack extension area is less than one tenth of the sintered Ag layer. This study will add to the understanding of the high temperature properties and high temperature reliability as well as the lifetime of Ag sinter joining in high-temperature applications.
TL;DR: In this article, a dual-metal junctionless nanotube field effect transistors (DMJN-TFETs) for improvised analog and digital applications are described, and compared with existing junctionless-gate all-around (J-GAA) metal oxide semiconductors (MOS) FETs, dual metal junctionless gate all around FET exhibits higher Ids, gm, gd and fT compared with the JNFETs.
Abstract: Dual-metal junctionless nanotube field-effect transistors (DMJN-TFETs) for improvised analog and digital applications are described. It has been realized that, compared with existing junctionless nanowire FETs, in particular, junctionless-gate all around (J-GAA) metal oxide semiconductors (MOS) FETs, dual-metal junctionless-gate all around (DMJ-GAA) MOSFETs, and junctionless nanotube (JN) FETs, DMJN-TFET MOSFETs exhibit higher Ids, gm, gd and fT compared with the JNFETs, making it a favorable device for high-frequency analog FET applications. DMJN TFETs exhibit a surpassing ION/IOFF ratio, with the subthreshold slope approaching the ideal values, a mitigated device channel resistance (Rch), advanced early voltage (VEA), a higher transconductance generation factor, maximum transducer power gain, unilateral power gain, and minimized noise conductivity and noise figure. Also, the small signal metrics including the transmission coefficients (S21 and S12) and reflection coefficients (S11 and S22) have been investigated to authenticate the small signal conduct of our device. These improvised characteristics make a DMJN-TFET the most suitable device design for both digital and analog applications employing FETs.
TL;DR: A comprehensive review of the research work on thermal runaway of lithium-ion batteries can be found in this paper, where the functions of each part of the battery and the related flame-retardant modification are summarized.
Abstract: Lithium-ion batteries are favored by the electric vehicle (EV) industry due to their high energy density, good cycling performance and no memory. However, with the wide application of EVs, frequent thermal runaway events have become a problem that cannot be ignored. The following is a comprehensive review of the research work on thermal runaway of lithium-ion batteries. Firstly, the functions of each part of the battery and the related flame-retardant modification are summarized. The thermal properties of the battery are improved by means of coating of cathode materials and adding anion receptors. Secondly, the thermal runaway behavior and its triggering mechanism are introduced, and the decomposition reactions of common cathode materials are analyzed. Finally, the methods of thermal runaway monitoring and thermal management are summarized to provide the reference for the safety of lithium-ion batteries.
TL;DR: An overview of the role of alloying tailors on the performance of representative GeTe, Sb 2 Te 3 , Ge 2 Sb2 Te 5 , and Sb-based systems containing Te and without Te is presented, followed by comparing the comprehensive performance of optimized systems.
Abstract: Phase change memory (PCM) based on chalcogenide compounds is considered to be an excellent candidate for next-generation memory because of its high speed, low energy consumption, high-density information storage, and durable stability. This has become a topic of general interest during the last two decades. Various systems have been proposed to explore more suitable compositions for PCM applications such as Ge-Te and Sb-Te binary alloys, GeTe-Sb2Te3 pseudo-binary alloys, and novel Te-free Sb-based alloys. In spite of this, the comprehensive performance of these pure systems still cannot fully satisfy the need for commercialization. Modification of alloys is an effective approach to enhance performance; this has been investigated significantly. Nevertheless, there are relatively few reports that directly provide integrated data on the effect of various alloying modifiers on the properties of PCM materials to obtain the relevant information conveniently, understand the role of chemical tailors on the properties of PCM materials deeply, and select modifiers matching the matrix systems efficiently. To achieve these goals and facilitate studies on PCM materials, this overview begins by summarizing and analyzing the role of alloying tailors on the performance of representative GeTe, Sb2Te3, Ge2Sb2Te5, and Sb-based systems containing Te (Sb2Te, Sb3Te, Sb4Te) and without Te (Sb-M), followed by comparing the comprehensive performance of optimized systems.
TL;DR: In this paper, an organic PU foam composite reinforced with nanoparticles was calculated with the help of mass and volume, and the response surface methodology was used to systematically design and analyze the experiments of EMI shielding effectiveness and the physical properties of the reinforced foam.
Abstract: The objective of this study is to prepare a bio-based and light-weight electromagnetic interference (EMI) shielding material in the range of 8–12 GHz. Organic castor oil-based polyurethane (PU) foam was synthesized by the mechanical stirrer mixing process, whereas absorption and hydrothermal reduction processes have been used to reinforce the multi-walled carbon nanotube (MWCNT), cupric oxide (CuO) and bamboo charcoal (BC) nanoparticles in the organic PU foam. The EMI shielding properties of the PU foam composite were tested using a vector analyzer test setup. Identification of the structural property of the nanocomposite was analyzed using field-emission scanning electron microscopy images. The density of the organic PU foam composite reinforced with nanoparticles was calculated with the help of mass and volume. Response surface methodology has been used to systematically design and analyze the experiments of EMI shielding effectiveness (EMI SE) and the physical properties of the reinforced foam. Using the EMI SE experimental results, mathematical models were developed to forecast the results and validate them with error estimation. An optimization study has revealed that 0.75 wt.% of MWCNT, 1.5 wt.% of CuO, and 1.5 wt.% of BC are the optimum parameters with 0.063750 g/cm3 density for obtaining the maximum EMI SE.
TL;DR: In this article, the authors investigated the effect of lead-free solders on the thermal cycling loadings and isothermal ageing of a lead-based eutectic Sn63Pb37 and four lead free Tin-Silver-Copper (SnAgCu) solders.
Abstract: Ball grid array (BGA) packages have increasing applications in mobile phones, disk drives, LC displays and automotive engine controllers. However, the thermo-mechanical reliability of the BGA solder joints challenges the device functionality amidst component and system miniaturisation as well as wider adoption of lead-free solders. This investigation determines the effective BGA solders for improved thermo-mechanical reliability of the devices. It utilised a conducted study on creep response of a lead-based eutectic Sn63Pb37 and four lead-free Tin–Silver–Copper (SnAgCu) [SAC305, SAC387, SAC396 and SAC405] solders subjected to thermal cycling loadings and isothermal ageing. The solders form the joints between the BGAs and printed circuit boards (PCBs). ANSYS R19.0 package is used to simulate isothermal ageing of some of the assemblies at − 40°C, 25°C, 75°C and 150°C for 45 days and model the thermal cycling history of the other assemblies from 22°C ambient temperature for six cycles. The response of the solders is simulated using the Garofalo-Arrhenius creep model. Under thermal ageing, SAC396 solder joints demonstrate possession of least strain energy density, deformation and von Mises stress in comparison to the other solders. Under thermal cycle loading conditions, SAC405 acquired the lowest amount of the damage parameters in comparison. Lead-free SAC405 and SAC387 joints accumulated the lowest and highest energy dissipation per cycle, respectively. It is concluded that SAC405 and SAC396 are the most effective solders for BGA in devices experiencing isothermal ageing and temperature cycling during operation, respectively. They are proposed as the suitable replacement of eutectic Sn63Pb37 solder for the various conditions.
TL;DR: In this article, the role of various carbon materials in composite SiO2/C to enhance the performance of SiO 2 materials has been analyzed, where the authors focus on analyzing the role that carbon materials play in compositeSiO2 materials.
Abstract: Lithium-ion batteries are promising energy storage devices used in several sectors, such as transportation, electronic devices, energy, and industry. The anode is one of the main components of a lithium-ion battery that plays a vital role in the cycle and electrochemical performance of a lithium-ion battery, depending on the active material. Recently, SiO2 has garnered attention for use as an anode in lithium-ion batteries. SiO2 has a high specific capacity, good cycle stability, abundance, and low-cost processing. However, the high expansion and shrinkage of the SiO2 volume during lithiation/delithiation, low conductivity, and solid electrolyte interphase formation resulted in damage to the electrode structure and caused a decrease in SiO2 performance as an anode for a lithium-ion battery. The modified properties of SiO2 and the use of carbon materials as composites of SiO2 are effective strategies to overcome these problems. This review focuses on analyzing the role of various carbon materials in composite SiO2/C to enhance the performance of SiO2 materials.
TL;DR: In this article, a double-gate junctionless tunnel field effect transistor (JNT) was analyzed for current gain (h21) and power gain with the help of a Silvaco Atlas device simulator.
Abstract: The optimum and acceptable combination of control gate (CG) process parameters, such as dielectric materials, thickness, and metal work function for a double-gate junctionless tunnel field-effect transistor, remain a subject of great interest among researchers. We report here on the significant impact of CG process variations on the radio-frequency (RF) parameters of this device structure. Studies carried out using a non-quasi-static model with CG process variations have been analyzed for current gain (h21) and unilateral power gain with the help of a Silvaco Atlas device simulator. Systematic investigations reveal that the combination of CG process parameters, such as dielectric material (SiO2) with the thickness of 2 nm and CG metal (aluminum-〈100〉), provide the optimum RF characteristics, i.e., fT (2.9 GHz) and fmax (15 GHz), while maintaining the switching ratio (0.161 × 109), intrinsic capacitances (Cgg = 0.7 fF), and transconductance (3.8 μS) at the bias conditions of Vgs (1 V) and Vds (1 V). The results have been thoroughly interpreted from energy band diagrams and the associated band-to-band tunneling rate. The studies reported here may prove to be useful for further exploring the use of the suggested device structure for Internet of Everything communications and other related applications.
TL;DR: In this paper, an ultra-compact metamaterial absorber (MMA) was proposed for microwave applications comprising two modified square-shaped resonators printed on a dielectric substrate and terminated by a metallic plane.
Abstract: In this study, an ultra-compact metamaterial absorber (MMA) has been proposed for microwave applications comprising two modified square-shaped resonators printed on a dielectric substrate and terminated by a metallic plane. The proposed MMA exhibits perfect absorption at 3.36 GHz, 3.95 GHz and 10.48 GHz, covering S- and X-band applications. The absorber is ultra-compact (0.112 λ) in size and ultra-thin (0.018 λ) in thickness at the lowest resonating frequency. The normalized impedance, constitutive electromagnetic parameters, electric field and surface current distribution have been studied to understand the physical mechanism of the triple-band absorption. Furthermore, the absorber is analyzed with different polarization and incident angles for transverse electric waves. The proposed MMA has been experimentally demonstrated to verify the results obtained from simulations. Moreover, the effect of over-layer thickness is investigated to examine the sensing application of the absorber.
TL;DR: In this article, a modification to the structure of an SnS/CdS solar cell to address the issue of its low experimental efficiency is reported, which primarily aims to control bulk recombination via passivation of the absorber bulk defect density and control of interfacial recombination through insertion of an intrinsic layer at the absorbers-buffer interface.
Abstract: We report a modification to the structure of an SnS/CdS solar cell to address the issue of its low experimental efficiency. The proposed structure primarily aims to control bulk recombination via passivation of the absorber bulk defect density and control of interfacial recombination via insertion of an intrinsic layer at the absorber–buffer interface. The device structure design is simulated with an SnS absorber, CdS buffer layer, and intrinsic layer with low hole density of ~ 1012 cm-3. The simulation approach matches the defect model to the experimental efficiency of the SnS/CdS structure to benchmark the parameters under varying conditions of bulk defect density, asymmetric carrier mobility, illumination, and temperature. The results confirm that the bulk recombination and fill factor losses are the major efficiency-limiting factors. Subsequent passivation of the bulk defect density in the absorber layer enhances JSC and the efficiency by controlling the bulk recombination. Insertion of an intrinsic layer at the SnS–CdS interface in the next level of simulation improves the fill factor. This approach enhances the fill factor to 62% from 54% for the benchmarked experimental cell. A substantial improvement is found in the open-circuit voltage (VOC) to 0.89 V from its experimental value of ~ 0.32 V. The two-tier optimization proposed in this work yields a fivefold higher efficiency of ~ 15.69% for the simulated optimal device structure when compared with the value of 3.16% reported experimentally and benchmarked initially herein to modify the device structure.
TL;DR: In this paper, different materials such as magnesium fluoride (MgF2), aluminum trioxide (Al2O3), tin oxide (SnO2), and magnesium oxide (mgO) were applied as a single antireflection coating (ARC) layer and characterized their optoelectrical properties of the resulting CdTe solar cells.
Abstract: Cadmium telluride (CdTe) is currently known to be one of the reliable cost-effective materials for manufacturing solar cells. In this work, different materials such as magnesium fluoride (MgF2), aluminum trioxide (Al2O3), tin oxide (SnO2), and magnesium oxide (MgO) were applied as a single antireflection coating (ARC) layer and characterized their optoelectrical properties of the resulting CdTe solar cells. A personal computer one-dimensional (PC1D) simulation study was carried out to instigate the overall performance when varying the thickness of the absorber and window layers. Simulation results confirmed that Al2O3 single ARC layer with thickness of 83 nm achieved the best efficiency of 17.81% as compared with the other ARC materials. The Al2O3 single ARC layer resulted in a short-circuit current of 2.89 A and open-circuit voltage of 0.740 V.
TL;DR: In this paper, the general concept of carbon nanotubes (CNT) electrical conductivities and how it enhances the electrical conductivity of electronic materials is presented, along with the methods used to prepare and fabricate the enhanced materials.
Abstract: Carbon nanotubes (CNTs) are used to enhance the electrical conductivity of electronic materials, due to their outstanding electrical properties. In this article, the general concept of CNT electrical conductivity and how it enhances the electrical conductivity of electronic materials is presented. The methods used to prepare and fabricate the enhanced materials are described, along with examples from selected work. We note that the CNT orientation and concentration within the enhanced material are the two main factors controlling the material electrical conductivity. Applications of each material are also reported so that the research efforts in material conductivity enhancement using CNTs are better appreciated. The applications of the enhanced materials range from consumer wearable electronics to precision biological electronic materials that can be inserted into the human body.
TL;DR: In this paper, the authors reported the synthesis of sodium ion-conducting polymer-blend electrolyte (NIPBE) thin films prepared by a standard solution-casting technique based on polyvinylpyrrolidone (PVP)/polyvinyl alcohol (PVA) and sodium bicarbonate (NaHCO3).
Abstract: We report the synthesis of sodium ion-conducting polymer-blend electrolyte (NIPBE) thin films prepared by a standard solution-casting technique based on polyvinylpyrrolidone (PVP)/polyvinyl alcohol (PVA) and sodium bicarbonate (NaHCO3). The as-synthesized NIPBE thin films were flexible, free-standing and displayed good mechanical stability. The prepared films were characterized using various experimental techniques including scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), AC impedance spectroscopy, linear sweep voltammetry (LSV), cyclic voltammetry (CV), Fourier transform infrared spectroscopy (FTIR) and UV–visible spectroscopy. The SEM, XRD and DSC studies revealed a reduction in the crystallinity of the polymer-blend electrolyte with an increase in the content of NaHCO3 due to the plasticization effect of Na-salts. The FTIR spectra show the complexation behavior of our as-prepared NIPBEs. The optical properties (i.e., direct and indirect optical energy bandgaps, optical absorption edge) were estimated using UV–visible spectroscopy studies. The dynamic ion behavior of all the as-prepared samples was assessed by the frequency-dependent AC conductivity of the NIPBEs. Also, the dielectric constant and dielectric loss (e′ and e″), and electric modulus (M′ and M″) vs. frequency plots at different concentrations and at room temperatures, were reported. The relaxation frequency (τs) of the NIPBE films was determined from the loss tangent spectra (tanδ). The ionic conductivity of NIPBE films was found to increase with sodium salt concentration, with maximum conductivity of the order of ∼10−5 S/cm at 30 °C. CV measurements showed good electrochemical stability of the sample containing a high concentration of Na salts. The optimized NIPBEs showed ionic conductivity and electrochemical voltage stability which is good for application in energy storage devices.
TL;DR: In this article, the Schiff bases and their metal chelates are used as a pure emitting layer or as a dopant material for the fabrication of R/G/B/white emitting devices.
Abstract: Optoelectronics is an active area of research and, for few decades, development of different semiconducting materials with a wide emission window has attracted researchers. Organic light emitting diodes (OLEDs) are primarily utilized in displays and light sources that greatly contribute towards the conservation of energy and do not need a backlight for displays. Development in device efficiency, lifetime and stability is now a major concern in this particular application, and designing efficient material for OLEDs has been an active field of research for decades. Metal-organic compounds possess different optical and electronic properties due to metal and organic ligand interactions which are primarily used in OLEDs. This review is mainly focused on the Schiff bases and their metal chelates as a pure emitting layer or as a dopant material for the fabrication of R/G/B/white emitting devices. Moreover, future prospects to explore further to advance research in the OLED arena are also discussed.
TL;DR: In this article, the authors discuss the mechanisms of whisker growth by critically examining the roles of stress and its regeneration, oxide layer, diffusion conduits, and crystal anisotropy.
Abstract: Whiskering is a spontaneous filamentary growth of material, and it is a major long-term reliability issue affecting microelectronic packages comprising Sn plating and Sn-rich solders. In particular, whisker growth out of Sn-plated surfaces has been studied extensively in recent years due to the advent of next-generation, environment-friendly, Pb-free microelectronic packaging. Here, we review this scientifically challenging and technologically important problem, especially in the light of relatively new insights gained in the recent past, intending to provide a quick overview of the important results and stimulating future studies. In particular, we discuss the mechanisms of whisker growth by critically examining the roles of stress and its regeneration, oxide layer, diffusion conduits, and crystal anisotropy in creating conditions conducive for whiskering. We also discuss the recent proposals for effectively mitigating whisker growth in Sn coatings. Finally, an outlook is provided, with details of important unresolved issues related to whisker growth.
TL;DR: In this paper, a series of poly(ethylene oxide) (PEO)-doped cobalt chloride (CoCl2) solid polymer electrolytes (SPEs) were successfully prepared.
Abstract: In the present work, using a simple solution cast technique, a series of poly(ethylene oxide) (PEO)-doped cobalt chloride (CoCl2) solid polymer electrolytes (SPEs) were successfully prepared. The effect of dopant on the morphology, structure, thermal, and electrochemical stability of the PEO films was systematically studied, and their ionic conductivity was examined. The Fourier transform infrared spectroscopy data provide evidence of the complex nature and existence of various microscopic interactions. The PEO ionic conductivity of 8.6 × 10−8 S cm−1 was found to increase to 3.5 × 10−3 S cm−1 upon the inclusion of 5 wt.% of CoCl2 at 303 K. An effort was made to understand the enhanced conductivity. Several studies were utilized to better understand the fundamental interplay of ion content and segmental motion using the Vogel–Tammann–Fulcher equation with typical investigations based on the fit of temperature-dependent conductivity data. The activation energy (Ea) decreased with increasing dopant concentration. The PCL5 transfer number (tion) was determined to be 0.93, evidence of the ionic nature of the doped electrolyte. Further, the purity and electrochemical stability of SPEs were studied using cyclic voltammetry and chronocoulometry. The thermal analysis showed reduced crystallinity and changes in glass transition and melting temperature at lower temperature, indicating enhanced amorphous content, thus confirming faster ion conduction. These SPEs with excellent electrical performance are promising candidates for electrolytes in solid-state batteries and other energy storage devices.
TL;DR: In this article, a palladium-capped copper oxide (Pd/CuO) thin film sensor was used to detect low concentrations of H2 gas for use in hydrogen-driven industries.
Abstract: In the present work, hydrogen gas sensing properties of palladium-capped copper oxide (Pd/CuO) thin films have been investigated. The Pd/CuO thin films were deposited on glass substrate for different deposition times (10–30 min) using direct current magnetron sputtering. The Pd/CuO thin films were characterized by x-ray diffraction, field emission scanning electron microscopy, atomic force microscopy and x-ray photoelectron spectroscopy for their structural, morphological and compositional properties, respectively. The Pd/CuO thin film sensor deposited for 10 min presents a remarkable sensing performance with fast response/recovery time of 10 s/50 s for hydrogen gas at a concentration of (1000 ppm) and optimum operating temperature of 300°C. The sensor is observed to be highly selective towards hydrogen (H2) gas compared to the other gases such as carbon monoxide (CO) and ammonia (NH3). The sensor is stable under high humidity conditions (60% RH). The studied Pd/CuO thin film sensor can be used to design a simple and low-cost sensor to detect low concentrations of H2 gas for use in hydrogen-driven industries.
TL;DR: In this paper, the In/p-SnSe Schottky diode was prepared by a thermal evaporation method and analyzed using a Ln (I)-V method and Cheung's method.
Abstract: Tin selenide (SnSe), a member of the IV-VI group, belongs to the layered transition metal chalcogenide (TMC) family. As TMCs are chemically inert, and have a binary layered structure of Sn-X (X = S, Se, Te) type, they are used widely in the areas of photovoltaic, electronic, and optoelectronic devices. In the present study, a direct vapor transport technique was used to grow single crystals. The synthesized crystals were examined with energy-dispersive analysis of x-rays, optical microscopy-scanning electron microscopy, and x-ray diffraction techniques to investigate the purity, surface morphology, and phase, respectively. The present work reports the use of a layered monochalcogenide single-crystal substrate for preparation of metal-semiconductor or Schottky junction devices. The In/p-SnSe Schottky diode was prepared by a thermal evaporation method. Analysis for the In/p-SnSe Schottky contact is based on the measurement of the current–voltage characteristics of the Schottky diode within the temperature range (313 K < T < 413 K). Characteristics were analyzed using thermionic emission theory and Schottky barrier diode parameters including barrier height, ideality factor, and series resistance, which were obtained and analyzed using a Ln (I)-V method and Cheung’s method. This work also reports the anisotropic current–voltage characteristics as well as the alteration in the Schottky barrier diode parameters at high temperature.
TL;DR: In this article, the green synthesis of silver nanoparticles (Ag NPs) from bio-reduction of Ag nitrate using different concentrations of medicinal plant extracts, namely, Mentha arvensis, Bryophyllum pinnatum and Dalbergia sissoo, was investigated.
Abstract: The present work deals with the green synthesis of silver nanoparticles (Ag NPs) from bio-reduction of Ag nitrate using different concentrations of medicinal plant extracts, namely, Mentha arvensis, Bryophyllum pinnatum and Dalbergia sissoo. The bio-synthesis route with a non-toxic approach is an attractive research topic in the area of nano-biomedicine and material science. Eco-friendly Ag NPs have been confirmed from the brown color of the solutions, and via UV–Vis spectroscopy. Further, Ag NP-conjugated l-cysteine capped ZnS:Mn quantum dots have been developed successfully. This prepared conjugation aims at antimicrobial activity using antibiotic-resistant gram-positive and gram-negative bacteria, namely, Staphylococcus aureus and Escherichia coli, respectively. In anti-microbial studies, a zone of inhibition (antibiotic sensitivity) was found to vary significantly with the varied concentration of Ag NPs that also depends on the specific type of plant extract. These studies may open the door for non-toxic material to synthesize plasmonic NPs for biosensors and detectors.
TL;DR: In this paper, the effects of the milling and SPS parameters as well as the specimen thickness were evaluated to obtain the best microstructural and thermoelectric properties of Bi2Te3 compounds.
Abstract: Bi2Te3 compound has been shown to exhibit the highest thermoelectric figure of merit at 573 K to 673 K. Bi2Te3 samples were synthesized by mechanical alloying (MA) followed by spark plasma sintering (SPS) in this work. The effects of the milling and SPS parameters as well as the specimen thickness were evaluated to obtain the best microstructural and thermoelectric properties. To synthesize Bi2Te3, Bi and Te powders were mechanically alloyed under argon atmosphere in a stainless-steel vial with a ball-to-powder weight ratio of 15:1 for different durations. The synthesized powders were then sintered using SPS at different temperatures. To characterize the Bi2Te3 powders and bulk samples, x-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS) analysis were applied. Furthermore, the bandgap energy was measured by ultraviolet–visible (UV–Vis) spectroscopy. Moreover, the Seebeck voltage and electrical conductivity were determined at different temperatures. The experimental results illustrate that, by enhancing the sintering temperature from 623 K to 673 K, the maximum Seebeck coefficient was increased from 136 μV/K to 156 μV/K. To investigate the effect of thickness, specimens were sintered at the optimum temperature of 673 K with thicknesses of 1 mm, 1.5 mm, 2 mm, 3 mm, and 4 mm. The results showed that, by decreasing the thickness, the maximum Seebeck coefficient was increased from 144 μV/K to 166 μV/K while the electrical conductivity was increased from 0.35 × 105 S/m to 1.42 × 105 S/m, resulting in an increase in the power factor from 0.76 mW/m-K2 to 3.94 mW/m-K2.