Conductivity Type Research Articles

Different audiometric findings with different symptoms for diagnosing superior semicircular canal dehiscence symptoms: a retrospective study of 12 cases

BackgroundDue to the patients with no symptoms for dehiscence but having audiological different findings who came to clinic, this study aims to evaluate the audiological characteristics of 12 cases diagnosed with superior semicircular canal dehiscence and to compare the findings with the literature.MethodsWe evaluated a case-series of 12 cases aged 11–59 years with a pre-diagnosis of semicircular canal dehiscence (SSCD) by clinical history and audiological evaluation between 2019 and 2022 and a final diagnosis by high-resolution computed tomography. Audiological evaluation includes air-bone conduction and speech audiometry, tympanometry, and acoustic reflex test.ResultsUnilateral dehiscence was observed in 6 cases, and bilateral dehiscence was observed in the other 6. Considering types of hearing loss, we observed 5 normal hearing, 1 mixed type, 2 conductive type, and 4 sensorineural type. Also, numerous clinical characteristics were observed: vestibular complaints (9/12), chronic imbalance (9/12), Tullio phenomenon (6/12), Hennebert sign (6/12), and tinnitus (5/12). Patients with symptoms no audiological findings and patients with audiological findings no symptoms were seen with dehiscence diagnosis.ConclusionVarious symptoms and findings were observed in patients with semicircular canal dehiscence. While patients with no symptoms for diagnosing dehiscence are presented, audiological findings with low-frequency hearing loss and air–bone gap can be landmark. In addition, patients with SSCD symptoms, even if they do not have audiometric findings, should be further evaluated with radiological evaluation.

Improvement of Lead-Free Bismuth Based Perovskite Solar Cell Efficiency with Graded Bandgap Structure

Lead (Pb) halide perovskite has been identified as a promising light-harvesting material for perovskite solar cells (PSCs) with power conversion efficiency (PCE) exceeding 26%. However, the toxicity of Pb-based materials and poisonous environment are the main hindrances that limit their reliable applications. Bismuth (Bi)-based perovskite has shown high potential to replace conventional Pb-based perovskite, but the PCE of Bi-based perovskite solar cells is far lower than Pb-based. Despite the early exploration of Bi-based materials, a fundamental understanding of the material properties and developing strategies, including device design to improve performance, are needed immediately. Here, we report the graded bandgap design for Bi-halide PSCs, which aims to enhance the output current and PCE by maximizing the solar spectrum through device architecture. Titanium dioxide (TiO2) was used as an electron transport layer (ETL), and Spiro-OMeTAD was used as a hole transport layer (HTL) due to its facile implementation and high performance in electronic devices. The variation of iodine concentration in bi-doped iodide sets up bandgap tuning and the conductivity type of the layer. This conFigureuration produces cells with desirable performance that effectively absorb the photons in almost all parts of the solar spectrum. Both open circuit voltage (Voc) (940 mV) and fill factors (~58%) for the best cells have shown drastic improvement over single active layer device, and the short current densities (Jsc) measured are in the range (20-30) mAcm-2. The effects of quasi-electric fields instigated by the graded bandgap structure in the active layers upon the illumination current density and open-circuit voltage of a solar cell will be discussed further.

Study of temperature dependences and electrical properties of thin films of Ag2S quantum dots

The results of studying the electrical properties of thin films of colloidal quantum dots (QDs), Ag2S/SiO2 and Ag2S/SiO2/Au, are interesting and important for understanding the behavior of these materials. Additional studies made it possible to determine the temperature dependences of conductivity in the range from 300 to 360 K, which made it possible to study changes in the electrical properties of materials depending on temperature. Activation energy values obtained from linear approximations of current-voltage characteristics in Arrhenius coordinates have become key to determining energy barriers and conduction mechanisms in these systems. Decorating Ag2S quantum dots with plasmonic gold nanoparticles also has the potential to improve the electrical properties of materials and create new functional characteristics. The results obtained can have a wide range of applications in the field of nanoelectronics, optoelectronics, sensors and other technologies that require precise control of the electrical properties of materials at different temperatures. Decoration of Ag2S/SiO2 QDs with plasmonic gold nanoparticles leads to an increase in the band gap from 0.29 to 0.89 eV. This effect can be explained by the interaction between gold plasmons and Ag2S/SiO2 electrons, which leads to a change in the properties of the material. It has been shown that decorating Ag2S/SiO2 QDs with Au nanoparticles leads to a change in the type of conductivity. Finally, calculating the mobility of charge carriers according to the Mott-Gurney model allows for a deeper understanding of the conductivity mechanisms in the presented thin-film structures.

Control of Integrated Circuits Crystals' Surface Microrelief and Defects of Heteroand Submicrostructures by the Atomic Force Microscopy Method

The aim of the work was to study the structure and defects of a channel transistor with two types of conductivity (p and n), the submicrostructures based on nickel silicide films, and the seed layers based on AlN using atomic force microscopy (including conductive or electric force method, which allow one to study the electrical conductivity of the material surface). The influence of the manufacturing technology and local oxide formation on the relief and structure of the pand n-type transistor was established. The local oxide is necessary for the electrical isolation of the transistors from each other. The surface roughness is higher on the surface and outside the p-channel transistor than on the n-channel transistor. When examining the AlN layers both in the topography mode and in the adhesion mode, defects in the form of pores were revealed, which are places of electrical breakdowns, which worsens the properties of the such heterostructures. With an increase in the temperature and time of nitriding, the defects of the AlN layers significantly decrease. The conductive areas on the surface of the nickel silicides after rapid thermal treatment at 300 and 400 °C using electric force microscopy were detected, which shows incomplete formation of nickel silicide during the treatment. Thus, the efficiency of the atomic force microscopy method using a specialized conductive technique as a method for monitoring microelectronic components was demonstrated.

Hearing Status and Etiology of Hearing Impairment Among the Patients Visiting Audiology OPD

Introduction: Hearing disability can impair individual quality of life. It can impede communication, disrupt an individual's psychological and social well-being, and cause them to become socially isolated. We aimed to study the hearing status and etiology of hearing impairment in the patients visiting ENT-Audiology OPD. Materials and Methods: This cross-sectional study was conducted in the ENT-Audiology Department at the National Medical College and Teaching Hospital. Patients suspected of hearing impairment were audiologically evaluated with a MAICO 52 audiometer. A pure tone audiogram was done in each ear of every individual separately and a copy of it was kept along with demographic data and clinical history. Results: Among 410 individuals, 51.9% were males and 48.1% were females; a maximum of individuals were 16-30 (36.6%) years and the mean age was 33.56. Among 410 (820 ears) individuals 16.34%had unilateral hearing impairment and 67.31 %had bilateral hearing impairment. In 686 pathological ears, 51.45% suffered from otitis media followed by presbycusis in 14.47%. The conductive type of hearing impairment in 36.21% of patients and a mild degree of hearing impairment in 36.34% of patients were the most common. Conclusions: The prevalence of hearing impairment in this region is high. Otitis media was found to be the main cause of hearing disability and a mild degree of hearing loss was more evident. Preventive measures, early identification, and treatment can reduce hearing-disabling conditions.

Tunable Transparent Conductors Based on SnO2: Theoretical and Experimental Studies of Codoping.

Transparent conducting oxides (TCOs) are widely used in modern electronics because they have both high transmittance and good conductivity, which is beneficial for many applications such as light-emitting diodes. Tailoring electronic states and hence the conductive types by design is important for developing new materials with optimal properties for TCOs. SnO2, with a wide band gap, low cost, no toxins, and high stability, is a promising host material for TCOs. Here, we performed a set of hybrid-exchange density functional theory calculations on the two-element and three-element codoped SnO2 by using Sr, Ta, Al, Ga, V, and Nb, which were then validated by the relevant experimental works on SnO2. As predicted by the first-principles calculations, the controllability of the electronic states to be n- or p-type can be demonstrated experimentally by varying the relative doping concentration between donors (Ta/Nb) and acceptors (Al/Ga). One of the main advantages for these codoping methods is that the charge neutrality problem caused by the dopant can be circumvented. The thin films fabricated showed a low sheet resistance (down to ∼450 Ω/□) and a high optical transparency (above 80%). The combination of our calculations and experimental material fabrication and characterizations has shown a great potential for codoping SnO2 for (i) the efficient processing of the integrated circuit composed of both p-type and n-type transistors (using the same target precursors during the deposition) and (ii) a good lattice matching for p-n junctions. Most importantly, our calculations, supported by the experimental works, point to a promising route to accelerate the discovery process for the alternative cost-effective and high-performance indium-free TCOs using computational material design.

Dramatic switchable polarities in conduction type and self-driven photocurrent of BiI3 via pressure engineering.

The intentional manipulation of carrier characteristics serves as a fundamental principle underlying various energy-related and optoelectronic semiconductor technologies. However, achieving switchable and reversible control of the polarity within a single material to design optimized devices remains a significant challenge. Herein, we successfully achieved dramatic reversible p-n switching during the semiconductor‒semiconductor phase transition in BiI3 via pressure, accompanied by a substantial improvement in their photoelectric properties. Carrier polarity flipping was monitored by measuring the photocurrent dominated by the photothermoelectric (PTE) effect in a zero-bias two-terminal device. Accompanying the p-n transition, a switch between positive and negative photocurrents was observed in BiI3, providing a feasible method to determine the conduction type of materials via photoelectric measurements. Furthermore, the combined effects of the photoconductivity and PTE mechanism improved the photoresponse and extended the detection bandwidth to encompass the optical communication waveband (1650nm) under an external bias. The remarkable photoelectric properties were attributed to the enhanced energy band dispersion and increased charge density of BiI3 under pressure. These findings highlight the effective and flexible modulation of carrier properties through pressure engineering and provide a foundation for designing and implementing multifunctional logic circuits and optoelectronic devices.

A Prospective Observational Study to Establish a Correlation Between Tinnitus and Hearing Loss

Introduction: The prevalence of tinnitus in adults with hearing problems is very high (59 - 86%). Both tinnitus and sensorineural hearing loss can occur when there is damage throughout the auditory pathway from the inner ear to auditory cortex. Our aim of the study was to evaluate the prevalence of hearing loss in patients with tinnitus and to assess the association between tinnitus and hearing loss. Materials and methods: This prospective observational study was conducted for 12 months between May 2022 and April 2023. 60 patients of both the sexes >15 years of age presenting with tinnitus in one or both ears were included in our study. Mentally ill and/or intoxicated patients were excluded. After clinical examination patients underwent Pure Tone Audiometry - average was calculated across 500, 1000, 2000, 4000 Hz in terms of air conduction, bone conduction and air bone gap. Hearing loss was classified as conductive, sensorineural and mixed types. Tinnitus pitch and loudness matching was done for which opposite ear was taken as test ear. In cases of bilateral tinnitus with equal intensity, right ear was taken first as test ear. In case of bilateral tinnitus with unequal intensity, ear with higher intensity tinnitus was tested first. Sensation level of tinnitus was calculated by subtracting the hearing loss threshold from tinnitus loudness in decibel. Result: In our study the mean age was found to be 44.20± 17.01years, with a male preponderance, and maximum number of cases complaining of left sided tinnitus. In an attempt to find a correlation between tinnitus and hearing loss, in right and left ears separately, ‘P’ value calculated to be <0.001.We also attempted to find a correlation between highest hearing loss and tinnitus loudness. We found that relative coefficient, ‘r’ being 0.309 on right side and 0.270 on left side. ‘P’ value on right is 0.097 and on left is 0.117. Conclusion: Since most of the cases of tinnitus also complaints of hearing loss, so it is necessary to identify a relation between the two. If a relation between tinnitus and hearing can be identified, it helps to identify the pathophysiology, which will further be helpful to plan the line of management. There are very limited number of studies conducted. Our study suggests a definite relation between tinnitus and hearing loss though there is no statistically significant correlation found between tinnitus loudness and highest hearing loss in the same ear.

Circulating Fetuin-A concentrations in rheumatic diseases: asystematic review and meta-analysis.

Rheumatic diseases (RDs) include a broad group of disabling conditions with different phenotypes, from autoimmune to autoinflammatory, degenerative, metabolic or mixed manifestations. With the continuous efforts to identify therapeutic targets for new biologic drugs to treat overt clinical manifestations, research is also focusing on the discovery of new biomarkers to diagnose and manage early disease stages. In this context, we conducted a systematic review and meta-analysis of Fetuin-A (FtA), a glycoprotein synthesized by the liver that participates in several biological processes and has been proposed as a biomarker for several disorders, including rheumatoid arthritis. A systematic search in PubMed, Scopus and Web of Science, from inception to the 24th of August 2024, led to the identification of 13 manuscripts from 219 records; six additional studies were identified through reference hand-search, for a total of 19 studies. There was a significant decrease in FtA concentrations in RD patients (standardized mean difference, SMD = -.91; 95% CI -1.43 to -.39, p = .001), with no substantial contribution from any individual study nor publication bias. The effect size was significantly associated with erythrocyte sedimentation rate, various lipid fractions, geographical area of study conduction, study design and specific type of RD. In conclusion, our study identified significant reductions in FtA concentrations in RD patients versus healthy controls. These alterations were significantly associated with specific study and patient characteristics. Further research is required to identify the exact pathophysiological mechanisms underlying these alterations and the possible utility of measuring FtA for the diagnosis and management of RDs.

Application of biomaterials in cardiac tissue engineering: Current status and prospects

AbstractCardiovascular diseases have become one of the leading causes of death and illness worldwide, posing significant challenges to global health. Due to the limited regenerative capacity of the heart, conventional approaches to treating heart diseases have demonstrated limited effectiveness. Therefore, leveraging biomaterials and biotechnologies in cardiac tissue engineering has emerged as a promising therapeutic strategy. This review aims to summarize the various characteristics of biomaterials in cardiac tissue engineering and their significance in addressing heart diseases. We categorize biomaterials into natural, synthetic, and conductive types based on their sources and unique properties, focusing on their applications in cardiac tissue engineering. We then present current applications of biomaterials in cardiac tissue engineering, followed by a discussion of existing challenges such as long‐term material stability, biocompatibility, adverse reactions, and precise application methodologies. Additionally, we provide insights into potential strategies for overcoming these challenges, aiming to enhance the effectiveness and safety of biomaterials in cardiac tissue engineering applications. Finally, this review highlights the potential of emerging biomaterials and technologies, underscoring the critical role of interdisciplinary collaboration in driving innovation and progress in cardiac tissue engineering.

Terrain's steepness governs sensitivity of urban oak forests to climate variability

Urban forests, vital for providing ecosystem services in cities, face challenges from climatic factors, particularly in heterogeneous urban environments. Kyiv, one of Europe’s largest and most populated cities, boasts a varied topography, with about 55 % of its area covered by forests, where Quercus robur predominates. In this study we investigate the sensitivity of Q. robur trees to climatic factors within Kyiv's urban forest, utilizing tree ring widths as a proxy. Employing dendrochronological approaches, we built nine site-mean ring-width chronologies and identified the growth pointer years and their frequency. Using moving windows in daily correlation analysis, we examined Q. robur response to climatic variations over the last 135 years. Additionally, linear mixed-effects models (LMMs) were applied to the site-specific characteristics such as slope steepness, altitude a.s.l., soil type, soil mechanical composition, soil pH, forest type and coefficient of soil saturated hydraulic conductivity, to identify which of them exert a significant influence on studied trees’ sensitivity to precipitation and temperature. Our results showed that the frequency of negative or positive pointer years in Q. robur growth coincides with extremely dry or wet years. The precipitation amount falling from the dormant period to the early growing season emerges as the key factor for Q. robur trees' radial growth. The trees' sensitivity to this factor was found to be significantly influenced by the slope steepness. Our findings contribute valuable insights into the complex interplay between urban heterogeneity, climatic factors, and the climatic sensitivity of Q. robur in urban areas. This research contributes to a deeper understanding of urban forests’ dynamics, proposing management strategies for slope stability, soil water retention, and natural tree regeneration.

Dual efficacy of potassium-doping in perovskite solar cells: Reducing hysteresis and boosting open-circuit voltage

The incorporation of potassium into perovskite solar cells (PSCs) has been empirically validated to mitigate hysteresis phenomena and boost the power conversion efficiency (PCE). However, the doping mechanism of potassium ions in the perovskite film and their effect on photocarrier recombination remains a topic of debate. Here, we grew doped MAPbI3: K single crystals by inverse temperature crystallization using KI as a dopant, and then perovskite thin films were spin-coated with dissolved MAPbI3: K crystals as a precursor. The doped MAPbI3: K perovskite films exhibit better crystal quality with large columnar grains and lower defect density. Employing Hall effect, ultraviolet photoelectron spectroscopy, and Kelvin probe force microscopy measurements, we definitively demonstrate that K-doping transforms the conductivity type of the perovskite film from a marginally N-type to a distinct P-type semiconductor. Furthermore, this doping strategy induces a concurrent downward shift in both the conduction band minimum and valence band maximum. As a result, the PCE of the PSCs increases from 15.15% to an impressive 20.66%, and the J–V curve hysteresis almost disappears. Additionally, theoretical simulations using SCAPS-1D software reveal a profound modification in the device's energy band diagram after K+-doping. Specifically, the energy level offset between the perovskite layer and the electron transport layer diminishes from 0.24 to 0.14 eV, with a result of bigger quasi-Fermi energy level splitting. This, in turn, elevates the open-circuit voltage (Voc) of the doped perovskite solar cell, underscoring the profound impact of potassium doping on enhancing PSC performance.

Influence of Conductive Filler Types on the Ratio of Reflection and Absorption Properties in Cement-Based EMI Shielding Composites

The growing importance of electromagnetic interference (EMI) shielding composites in civil engineering has garnered increasing attention. Conductive cement-based composites, incorporating various conductive fillers, such as carbon nanotubes (CNTs), carbon fibers (CFs), and graphene nanoplatelets (GNPs), provide effective solutions due to their high electrical conductivity. While previous studies have primarily focused on improving the overall shielding effectiveness, this research emphasizes balancing the reflection and absorption properties. The experimental results demonstrate an EMI shielding performance exceeding 50 dB, revealing that filler size (nano, micro, or macro) and shape (platelet or fiber) significantly influence both reflection and absorption characteristics. Based on a comprehensive evaluation of the shielding properties, this study highlights the need to consider factors such as reflection versus absorption losses and filler shape or type when optimizing filler content to develop effective cement-based EMI shielding composites.

Characterization of ZnSe Thin Film Electrodeposited at Room Temperature in Aqueous Medium without Complexing Agents

This study includes a simple electrodeposition technique for the fabrication of ZnSe thin film at room temperature and in an aqueous medium without additional complexing agents. Comprehensive analysis of the optical, structural, and morphological characteristics of the ZnSe thin film electrodeposited onto an ITO substrate was conducted using UV-Vis spectrometry, X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), and field emission–scanning electron microscopy (FE–SEM). Furthermore, the photoelectrochemical properties were evaluated through current-time (I-t) measurements and electrochemical impedance spectroscopy (EIS) under light on/off conditions. Mott-Schottky analysis was also performed to determine the conductivity type, carrier concentration, and flat band potential of the ZnSe thin film. Structural investigations revealed that the ZnSe thin film has a hexagonal structure, the longitudinal optical (LO) phonon mode, stretching and bending vibration modes of Zn-Se. The carrier type of the ZnSe thin film was identified as n- type semiconductor and photoelectrochemical measurements exhibited a photoresponse under the light illumination

Hard Copper Boride with Exceptional Conductivity.

Copper and boron seldom engage in reaction at ambient pressure. The few reports on copper-doped boron compounds that exist in the literature often lack definitive stoichiometry. Here, we report successful synthesis of Cu_{2-δ}B_{25} single crystals (δ∼0.03, indicating Cu understoichiometry) via a high-pressure melting method using copper and β-rhombohedral boron as precursors. Crystals thus synthesized are characterized by a tetragonal boron sublattice, within which Cu atoms are either partially or fully situated at different interstices between B_{12} icosahedra. The crystals possess a high Vickers hardness of 26.5GPa and an unusually high electrical conductivity of 1.19×10^{5} S/m-the highest conductivity among the icosahedron-based borides. Hall measurements reveal a notable p-n conduction type transition around 30GPa. This transition, alongside the remarkable conductivity, is potentially modulated by the copper content and its valence states within the structure. The synthesis of Cu_{2-δ}B_{25} not only broadens the spectrum of hard materials but also opens new avenues for innovative modulation of electronic properties in boron-rich compounds, with promising technological implications.

Finite automated system to design a high efficiency LLC resonant converter system for 3 kW. PV solar array

A combination of electrical circuit design and the Finite Automation model leads to improved efficiency in terms of memory usage, computation time, and overall performance. LLC resonant converters are known for their high efficiency and ability to convert DC voltage from solar panels into the desired AC voltage for grid-tied or off-grid PV systems. However, designing, testing, and implementing LLC in a PV system requires careful consideration of various factors, including voltage and current requirements, resonant frequency, and compliance with standards and regulations. Eight cases are taken for this purpose with a special case of a 3kW-PV module. The major parameters for the LLC resonant Converter were 480-500V. as output voltage for 36-40V. input voltage range with a 39V. nominal voltage. The calculated coefficients for these values were as follows: A = C = 7.29, B = -50.58, D = -0.25, and E = -11. Combining LLC circuit design with FA, it is providing 94.5 % efficiency through selecting precise parameters that minimized overall calculated losses such as conductive and switching types. The right path and accepted words for different cases are given to provide several solutions with the correct path of design. ZVS and ZCS have been obtained through precise selection process of phase shift between Half Bridge of LLC circuit achieved by this design.

Dopant compensation in component-dependent self-doped Cs2SnI6 thin films grown with PLD at room temperature

Tetravalent tin (Sn4+)-based inorganic perovskite semiconductors like Cs2SnI6 are expected to replace lead-based perovskite counterparts due to advantages such as structural stability and environmental friendliness. In this paper, we reported the dopant compensation effect in the component-dependent self-doped (111)-oriented Cs2SnI6 thin films grown with pulsed laser deposition (PLD) at room temperature. The films were grown on (100)-SrTiO3 (STO) substrates at room temperature by PLD. Hall results of the Cs2SnI6 films with different components realizing by controlling the ratio of SnI4/CsI in the targets demonstrate a clear change of conductivity type from N-type to P-type, while the carrier concentration decreases from 1018 to 1013 and accordingly the film resistivity increases significantly from 3.8 to 2506 Ω cm. The defect-related optical fingerprints of Cs2SnI6 films were also investigated with temperature-dependent photoluminescence spectroscopy. At low temperatures of 10 K, the Cs2SnI6 films exhibit donor-bound (D0X) and donor-acceptor pair (DAP) emission, respectively, due to the self-doping effect. These results indicate that controlling the composition of the PLD target is a powerful way to tune the electrical properties of Cs2SnI6 films for possible applications in solar cells or X-ray detectors.

Study of Near Band Edge Emission Spectra and Conductivity Transformation in Fe‐Doped Cadmium Telluride Nanoparticles for the Device Applications

AbstractThe research work discussed here explains the near band edge emission and conductivity transformation of the Fe‐doped CdTe nanoparticles synthesized by hydrothermal method by using an autoclave. The size of the undoped CdTe nanoparticles is found to be 5.48, 8.45, 9.40, and 14.79 nm, respectively for the nanoparticles collected at 15, 30, 45, and 60 minutes of duration of the synthesis. Whereas for the Fe‐doped CdTe nanoparticles, the size is found to be 12.81, 16.9, and 18.5 nm, respectively for the 10%, 20%, and 30% Fe concentrations as doping elements in CdTe nanoparticles. The XPS spectra clearly show the successful doping of Fe in the CdTe QDs and also the orbital state of Fe in CdTe. The EDAX spectra is taken to trace the elements present in the synthesized nanoparticles. From the UV–vis absorption spectrum, the band gap is found to decrease when doped with Fe in different concentrations. Also, an appreciable blue shift is found in the as synthesized undoped and Fe‐doped CdTe NPs. A near band edge emission property is observed for the Fe‐doped CdTe NPs when doped with different Fe concentrations. The van der Pauw Hall measurement technique is employed to study the electrical properties such as conductivity, carrier concentration, mobility, and Hall coefficient of the undoped and Fe‐doped CdTe nanoparticles. The consistent p‐type conductivity is observed for the undoped CdTe nanoparticles till the time duration of 45 minutes of synthesis. When doped with Fe in 30% concentration, the type of conductivity is found to transform from p‐type to n‐type. The luminescence property between 450 and 500 nm makes these materials suitable for device applications like light‐emitting diodes. Also, the study of Hall measurement here explains the application of these materials as photovoltaic cells.

The Thermal Stability and Photoluminescence of ZnSeO3 Nanocrystals Chemically Synthesized into SiO2/Si Track Templates

We report the effect of high-temperature treatment on the structure and photoluminescence of zinc selenite nanocrystals (ZnSeO3) deposited into SiO2/Si track templates. The templates were formed via irradiation with Xe ions (200 MeV, 108 ions/cm2) followed by etching in HF solution. ZnSeO3 nanocrystals were obtained via chemical deposition from the aqueous solution of ZnCl2 and SeO2 as Zn-, Se- and O-precursors. To estimate the thermal stability of the deposited precipitates, heat treatment was carried out at 800 and 1000 °C for 60 min in a vacuum environment. Scanning electron microscopy (SEM), X-ray diffractometry (XRD), photoluminescence (PL) spectroscopy, and electrical measurements were used for the characterization of ZnSeO3/SiO2nanoporous/Si nanocomposites. Thermal treatment of the synthesized nanocomposites resulted in structural transformations with the formation of ZnSe and ZnO phases while the content of the ZnSeO3 phase decreased. For the as-deposited and annealed precipitates, an emission in the range of (400 to 600) nm was observed. PL spectra were approximated by four Gaussian curves with maxima at ~550 nm (2.2 eV), 488 nm (2.54 eV), ~440 nm (2.82 eV), and 410 nm (3.03 eV). Annealing resulted in a decrease in PL intensity that was possibly due to the weight loss of the deposited substance during high-temperature treatment. The redistribution of maxima intensities after annealing was also observed with an increase in blue and violet emissions. The origin of the observed PL is discussed. The I–V curve analysis revealed an electronic type of conductivity for the ZnSeO3(NCs)/SiO2nanoporous/Si structure. The values of the specific conductivity were calculated within the percolation model. The sample annealed at 800 °C showed the highest specific conductivity of 8.5 × 10−6 Ohm−1·cm−1.

Effect of the solder conductive particles and substrate widths on the current carrying capability for flex-on-board (FOB) assembly

PurposeThe study aims to ascertain the influence of solder conductive particle types and substrate widths on the current carrying capability of flex-on-board (FOB) assemblies. By comparing Sn58Bi and SAC305 particles and varying substrate widths, the research sought to provide insights into the stability and performance of solder joints under different scenarios, particularly in high-power applications.Design/methodology/approachThe study used a comprehensive design/methodology, encompassing the investigation of solder conductive particle types (Sn58Bi and SAC305) and substrate widths on the current carrying capability of FOB assembly. Stable solder joints were obtained by manipulating the curing speed of anisotropic conductive films for both particle types. Various tests were conducted, including current carrying capability assessments under differing conditions.FindingsThe study revealed that larger substrate widths yielded higher current carrying capability due to increased contact area and reduced contact resistance. Notably, solder joints remained stable beyond the solder melting temperature due to encapsulation by cured epoxy resin. SAC305 solder joints exhibited superior current carrying capability over Sn58Bi in continuous high-voltage conditions. The results emphasized the stability of SAC305 solder joints and their suitability for robust interconnections in high-power FOB assemblies.Originality/valueThis study contributes by offering a comprehensive assessment of the impact of solder particle types and substrate widths on solder joint performance in FOB assemblies. The finding that SAC305 joints outperform Sn58Bi under continuous high-voltage conditions adds significant value. Moreover, the observation of stable solder joints beyond solder melting temperature due to resin encapsulation introduces a novel aspect to solder joint reliability. These insights provide valuable guidance for designing robust and high-performance interconnections in demanding applications.