•Investigate the changes of RF sliding contact under normal operation and contact failure by electromagnetic field simulation.•Summarized the changes in electrical characteristics of RF sliding ...contact under different degrees of contact failure.•Studied the influence of introducing specific spring on the working state of RF sliding contact.
As a component in the ICRH system that facilitates assembly, sliding and the mitigation of thermo-mechanical stress, a comprehensive understanding of the electrical behaviour of RF sliding contact under failure conditions is crucial for ensuring reliable radio-frequency transmission and the safety of the ICRH system. This article unveils changes in the electrical characteristics of RF sliding contact under contact failures by electromagnetic field simulations: when contact failure occurs, the current flows into the failed area and a significant local stronger electric field appears in the failure area. The maximum surface electric field strength and average current density on the failure surface of the RF sliding contact increase with the expansion of the non-contact ratio and decrease with the enlargement of the non-contact gap. Furthermore, contact failures exacerbate the degradation of the transmission performance of coaxial transmission lines. Adding the spring to RF sliding contact is usually considered to reduce the likelihood of RF sliding contact failure. Electromagnetic field simulation results indicate that installing the spring can decrease the maximum electric field strength of RF sliding contact failure surfaces and minimize signal mismatch of the transmission line when contact failures occur. However, the presence of the spring also leads to an increase in the average current density on the contact failure surface. Nevertheless, the increase in this current density-induced heat effect can be offset by enhancing the cooling capacity of the cooling device in the RF sliding contact. This study provides a new reference for the design of RF sliding contact in high-power ICRH systems for future fusion reactors.
Solar‐blind deep ultraviolet (DUV) photodetectors have been a hot topic in recent years because of their wide commercial and military applications. A wide bandgap (4.68 eV) of ternary oxide Zn2GeO4 ...makes it an ideal material for the solar‐blind DUV detection. Unfortunately, the sensing performance of previously reported photodetectors based on Zn2GeO4 nanowires has been unsatisfactory for practical applications, because they suffer from long response and decay times, low responsivity, and quantum efficiency. Here, high‐performance solar‐blind DUV photodetectors are developed based on individual single‐crystalline Zn2GeO4 nanowires. The transport mechanism is discussed in the frame of the small polaron theory. In situ electrical characterization of individual Zn2GeO4 nanowires reveals a high gain under high energy electron beam. The devices demonstrate outstanding solar‐blind light sensing performances: a responsivity of 5.11 × 103 A W−1, external quantum efficiency of 2.45 × 106%, detectivity of ≈2.91 × 1011 Jones, τrise ≈ 10 ms, and τdecay ≈ 13 ms, which are superior to all reported Zn2GeO4 and other ternary oxide nanowire photodetectors. These results render the Zn2GeO4 nanowires particularly valuable for optoelectronic devices.
High quality single‐crystalline Zn2GeO4 nanowires are synthesized via chemical vapor deposition. Photodetectors based on individual nanowires demonstrate outstanding solar‐blind light sensing performance: a responsivity of 5.11 × 103 A W−1, external quantum efficiency of 2.45 × 106%, detectivity of ≈ 2.91 × 1011 Jones, τrise ≈ 10 ms, and τdecay ≈ 13 ms.
In this paper, a scheme of pulse combustion mode with pulse input of gas is proposed to solve the problems of low output electrical performance and energy conversion efficiency of combustion-based ...thermoelectric systems under limited heat dissipation conditions, which is based on experiments. The characteristics of the thermoelectric system show that pulse combustion mode can increase the instantaneous temperature difference, so as to achieve the excitation effect on the output power. The relationships among output power, system efficiency, excitation intensity and pulse input parameters, and the geometry of thermoelectric modules are obtained. The influence of pulse input parameters on the excitation intensity is interactive, and top dead center of pulse inlet power is the parameter that has the greatest influence on the performance. Compared to the constant combustion mode, the pulse combustion mode can increase the output power by up to 28.3%. A maximum output power of 7.15 W with air-cooled heat dissipation and a maximum system efficiency of 3.26% were experimentally obtained, which is a 30% increase in efficiency over current air-cooled heat dissipation thermoelectric systems. Therefore, this paper can provide solutions for more practical power supply, provide effective and feasible guidance for the study of thermoelectric systems, and provide useful insights into the electrical properties of thermoelectric systems.
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•An air-cooled combustion based thermoelectric system was built.•A scheme of pulse combustion mode with pulse input of gas is proposed.•The pulse combustion mode can increase the output power by up to 28.3%.•High output power and efficiency results were obtained by experiment.•The power shortage is alleviated under limited heat dissipation conditions.
Understanding the impact of energetic ion irradiation on semiconductor materials and devices is essential for optimizing their electronic applications. This knowledge contributes to the broader goal ...of tailoring material properties to enhance the overall performance and reliability of semiconductor devices. In this study, we investigate the impact of 1.2 MeV Ar8+ irradiation on Au/n-Si Schottky barrier structures in-situ, as a function of ion irradiation fluence. Electrical characterization was performed in-situ on a single sample to mitigate any variability in device parameters between samples. It is observed that ion irradiation results in an increased Schottky barrier height with a reduction in reverse leakage current. The behavior is attributed to dopant deactivation by the energetic ion irradiation-induced defects near the interface. These results underscore the importance of understanding ion irradiation impacts on semiconductor devices, providing valuable insights for optimizing Schottky diodes in electronic applications.
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•Stability of metals and diamond interface supercells are evaluated through the calculation of binding energy.•Reliable interfacial atomic models and detailed interface electronic ...structures are provided.•Potential application of each metal as an electrode was evaluated by Schottky barrier heights.
Diamond electronic devices have attracted great attention in the field of high power and high frequency applications due to their excellent properties. For diamond electronics, metal and diamond contacts are important for the electronic device performance, with Schottky barrier heights (SBHs) playing a crucial role in the transmission properties of diamond devices. To make sense of their electrical characteristics, the interface supercells of diamond (111) with diverse metals have been explored using first-principles calculations. Clear metal-induced gap states (MIGS) can be observed at the interface, resulting in an enhanced Fermi-level pinning effect, with a pinning factor of 0.3. The results surprisingly show that there is a larger transverse tunneling probability and a smaller longitudinal tunneling probability for all diamond contact interfaces. All interfaces studied are p-type contacts with the metal Fermi level close to the diamond valance band edge. The low work function metals such as Sc and Ti are excellent at generating Schottky contacts with relatively higher SBHs (∼1.0 eV ± 0.6 eV). Pt and Ni have a smallest barrier height of ∼ 0.5 eV, making them ideal for ohmic electrodes with low contact resistance. The calculated SBHs are within the range of the experimental findings. This work gives insight into the electrical structural changes at the contact interface between metal and diamond, which provides a theoretical basis for selecting suitable electrodes for high-power diamond devices.
The study examines the surface topology, optical, structural and electrical characteristics of e-beam evaporated manganese dioxide (MnO2) films on p-InP using AFM, FESEM, UV–Vis, XRD, XPS and I–V ...procedures. The surface roughness of the MnO2 was smooth from AFM and FESEM analysis. The optical bandgap of MnO2 film was extracted from Tauc's plot. The outcomes endorse that the MnO2 layer deposited on InP. Then, the Ti/MnO2/p-InP heterostructure (HS) was created with an MnO2 interlayer to check the consequence of MnO2 on the electrical features of the Ti/p-InP Schottky diode (SD). The I–V results demonstrated that the higher Φb is acquired for the HS (0.90 eV) than the SD (0.84 eV), implying the MnO2 layer alters the Фb. Also, the Фb, ‘n’ and RS of the SD and HS can be determined by utilizing Cheung's and Norde's functions. The estimated Фb was almost similar, indicating the methodologies applied here are sturdy and effective. The determined NSS of the HS is lesser than the SD, implying that the MnO2 interlayer has a significant role in the decrease in NSS. The forward bias log (I)-log(V) plot of the SD and HS indicates that the ohmic behavior and space charge limited the conduction process at lower-bias and higher-bias segments, respectively. The study outcomes suggested that the transition metal oxide MnO2 layer would be favourable for creating MIS devices.
In this work, bottom-contact p-type organic thin-film transistors based on small-molecule benzanthracene with various channel lengths were fabricated, characterized, and theoretically investigated. ...The fabricated devices showed a pronounced shift for threshold voltage as the function of channel length. Electrical parameters characterizing fabricated devices have been systematically evaluated as a function of channel length with and without contact resistance in the calculation. Contact resistance (Rc) and channel resistance (Rch) are extracted individually using the transfer line method (TLM) for output characteristic curves that were done only at low drain voltage (linear regime). The effect of contact resistance on the values of various OTFTs parameters is more pronounced in short channel length devices. The obtained results revealed that the linear regime's corrected mobilities of short channel devices are about 15% smaller than uncorrected mobility. Comparatively, the corrected threshold voltage values were found to be nearly close to uncorrected values for all channel lengths. The analytical model was also applied to reproduce output characteristics in the linear regime of different channel lengths devices with or without contact resistance. It was found that the calculated results were in good agreement with the measured results (when considering the effect of contact resistance), which confirms that the used model can correctly describe the charge transport in these kinds of devices.
•Multiple small molecule benzanthracene based OTFTs were fabricated, characterized, and modeled.•Electrical properties of benzanthracene OTFTs were affected by channel length (L) and contact resistance (Rc).•The effect of Rc is more dominant in short-channel device.•Contact resistance corrected-electrical characteristics in linear regime.•Corrected output drain current values with including contact resistance is in good agreement with the measured data.
A lead free multiferroic material, Bi(Co0.45Ti0.45Fe0.10)O3 (BCTF45/10) was synthesized by a solid-state reaction route at high temperatures. BCTF45/10 powder was prepared using appropriate raw ...maretials in oxide powders with methanol medium. As-prepared circular shaped pellets were sintered at 1053 K for 6 h to produce a compact form. Preliminary structural properties and elemental analysis were determined using X-ray diffraction and energy-dispersive X-ray spectroscopy techniques respectively at room temperature. The microstructure or surface morphology of the sintered sample was carried out by using field emission scanning electron microscope (FE-SEM). The XRD analysis shows that the compound exhibits the single-phase of orthorhombic symmetry. The average crystallite size estimated using the Scherrer's technique was found to be 30 nm. The influence of Co and Ti substitution (at Bi and Ti sites of BiFeO3) on some physical and electrical properties of BiFeO3 was examined by using phase sensitive multimeter in a wide frequency and temperature ranges. The magnetic nature of the sample was studied using vibrating sample magnetometer. Study of room temperature magnetic hysteresis loop exhibits the enhanced ferromagnetic characteristic with saturation magnetization of 5.091 emu/g and coercive field of 0.213 kOe respectively. The enhanced magnetic properties highlight various potential applications of Co/Ti doped BCTF45/10 materials.
Nowadays, much attention is paid for the development of lead-free complex or mixed metal oxides, which can be utilized for multi-functional devices. This communication provides the information on ...synthesis (by mixed oxide route) and physical properties (structural, electrical and ferroelectric) of the polycrystalline sample of Bi(Fe0.9La0.1)O3 Analysis of the phase formation and basic crystal data of the material using X-ray diffraction (XRD) technique shows an orthorhombic symmetry with well-defined cell parameters. It has been shown that a small amount (10%) of La substitution at the Fe site of BiFeO3 suppresses the impurity phase usually observed during phase formation of BiFeO3. The average crystallite size, calculated through applying Scherrer's technique, was found to be 68 nm. For the study of surface morphology (grain size and distribution) of the compound, the scanning electron microscope (SEM) was used. The grains of different dimension were found homogeneously distributed at the entire surface of the sample. The La substitution strongly affects the capacitive (dielectric) and resistive (electrical) characteristics of bismuth ferrite in a wide range of frequency and temperature. The contributions of grains and grain boundaries in the capacitive as well as in the resistive properties of the material at different temperatures and frequencies were studied by means of the impedance spectroscopy technique. This study has provided numerous useful and interesting data which may find potential industrial applications.
Electrical properties of CdTe single crystals, doped by Mn (1 × 1017–1 × 1019 at/cm3), were studied in the wide temperature range using high-temperature Hall effect measurements.
To explain the ...obtained electrical properties the numerical simulation of the structure of both native and foreign point defect densities in the crystals was applied. Between the possibilities of whether predominantly Mn-single donors only or combined with Mn-containing associates occurrence in the crystals the second possibility was confirmed.
High-temperature electrical measurements were explained in the framework of the Kröger's theory of quasi-chemical reactions between point defects in solids. It was done by investigating the series of differently Mn-doped CdTe single crystals. In the 1 × 1017–1 × 1019 at/cm3 Mn concentration range the measured free electron densities at high-temperature defect equilibrium were almost identical indicating clear donor activity of the dopant.
•High-temperature electric measurements in CdTe single crystals.•Quasi-chemical approach and use of numeric simulation at treating these data.•Manganese solubility in CdTe limited to ~1 × 1017 at/cm3 at 873–1073 K.•Mn(Cd) in CdTe acting as donors with E(d) = 0.10 eV.•Existence in the crystals both individual Mn(Cd) donors and its associates with V(Cd).
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