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In this paper, using a scanning electron microscope (SEM) and atomic analysis, the location map of microcomposites formed on the surface of n-Si, p-Si, n-Si and p-Si samples was studied. Force microscope (AFM) research devices. The atomic fractions of inclusions of carbon, oxygen and lutetium formed on the surface of the samples were studied. Also, using the ASM device, the sizes, relief and topographic appearance of defects formed on the surface of the samples were determined. In silicon samples doped with Lu, a decrease in the size of surface defects and the formation of nano-sized structures were found, which makes it possible to obtain materials with a more perfect crystal structure. Using a ZEISS GeminiSEM 300 scanning electron microscope, the structural structure, chemical composition and images of their arrangement of n-Si, p-Si, n-Si and p-Si samples were obtained. In this case, the electron accelerating voltage was 20 kV, and the pressure in the sample chamber was (10-3 mmHg). Research results show that the structural structure of micro- and nanocomposites formed in silicon mainly depends on the diffusion time and cooling rate of the samples after diffusion annealing.

In this paper, we report the modelling of quantum capacitance in both single-layer and bilayer graphene devices to investigate the temperature dependence. The model includes the existence of electron and hole puddles due to local fluctuations of the potential, which is taken into account with the possibility of finite lifetimes of electronic states to calculate the quantum capacitance using the Gaussian distribution. The results indicate that the simulations are in agreement with the experimental measurements, which proves the accuracy of the proposed model. On the other hand, temperature dependence around the charge neutrality point has been reported for both single and bilayer graphene.

Thin films of pure NiO and doped with Zn are prepared by varying dopant concentration using spray pyrolysis. This paper presents the characteristics of thin films, including their structure, morphology, chemical composition, optical properties, and gas-sensing abilities. By adding 2 wt% Zn to pure NiO matrix, the film's structural, morphological, and ability to sense ammonia gas were notably changed. The Zn-doped NiO thin films were effective ammonia gas sensors with reliable performance at room temperature, making them suitable for real-time detection and monitoring of ammonia vapours. Gas-sensing studies suggest that the Zn-doped NiO thin film gas sensor can simultaneously improve stability, reproducibility, and sensitivity. Additionally, the NiO thin film of the p-type has a higher binding affinity for NH3 gas than other test gases. The 2 wt% Zn-doped NiO thin film exhibited an excellent response of 53.2 with response and recovery times of 24 and 30 s towards 25 ppm of NH3 at room temperature.

Photocatalysis is considered as the promising energy conversion way to resolve the issues of energy crisis and environmental pollution. As the key point of the photocatalysis, the photocatalyst determines the final conversion efficiency from solar, therefore, the composition and photoelectronic nature of which deserve to be valued. Halogen often affects immensely the intrinsic electron configuration of the matrix because of electrophilic property, and thus its topic has attracted lots of attention for photocatalytic application. In this review, halogen-contained organic porous semiconductors are discussed in detailed. Firstly, the role of halogens in photocatalysis based on organic porous semiconductors are categorized. Then, the way to introduce the halogens into organic porous semiconductors and their applications in photocatalysis are reviewed. At last, the outlooks are given at the end of this paper. This review would bring new insights into the non-metal doping engineering for improving the photocatalytic performance of organic semiconductors.

In this paper, the effect of doping and nanostructuring on the electrostatic potential across the electrochemical interface between a transition metal oxide and a water electrolyte is investigated by means of the Poisson–Boltzmann model. For spherical nanoparticles and nanorods, compact expressions for the limiting potentials at which the space charge layer includes the whole semiconductor are reported. We provide a quantitative analysis of the distribution of the potential drop between the solid and the liquid and show that the relative importance changes with doping. It is usually assumed that high doping improves charge dynamics in the semiconductor but reduces the width of the space charge layer. However, nanostructuring counterbalances the latter negative effect; we show quantitatively that in highly doped nanoparticles the space charge layer can occupy a similar volume fraction as in low-doped microparticles. Moreover, as shown by some recent experiments, under conditions of high doping the electric fields in the Helmholtz layer can be as high as 100 mV/Å, comparable to electric fields inducing freezing in water. This work provides a systematic quantitative framework for understanding the effects of doping and nanostructuring on electrochemical interfaces, and suggests that it is necessary to better characterize the interface at the atomistic level.

Abstract Understanding the adsorption interactions between carbon materials and sulfur compounds has far‐reaching impacts, in addition to their well‐known important role in energy storage and conversion, such as lithium‐ion batteries. In this paper, properties of intrinsic B or Si single‐atom doped, and B–Si codoped graphene (GR) and graphdiyne (GDY) were investigated by using density functional theory‐based calculations, in which the optimal doping configurations were explored for potential applications in adsorbing sulfur compounds. Results showed that both B or Si single‐atom doping and B–Si codoping could substantially enhance the electron transport properties of GR and GDY, improving their surface activity. Notably, B and Si atoms displayed synergistic effects for the codoped configurations, where B–Si codoped GR/GDY exhibited much better performance in the adsorption of sulfur‐containing chemicals than single‐atom doped systems. In addition, results demonstrated that, after B–Si codoping, the adsorption energy and charge transfer amounts of GDY with sulfur compounds were much larger than those of GR, indicating that B–Si codoped GDY might be a favorable material for more effectively interacting with sulfur reagents.

This paper reports the fabrication of silicon PN diode by using DNA nanostructure as the etching template for SiO2 and also as the n-dopant of Si. DNA nanotubes were deposited onto p-type silicon wafer that has a thermal SiO2 layer. The DNA nanotubes catalyze the etching of SiO2 by HF vapor to expose the underlying Si. The phosphate groups in the DNA nanotube were used as the doping source to locally n-dope the Si wafer to form vertical P-N junctions. Prototype PN diodes were fabricated and exhibited expected blockage behavior with a knee voltage of ca. 0.7 V. Our work highlights the potential of DNA nanotechnology in future fabrication of nanoelectronics.

In this paper, V2O5 thin-films were deposited on glass substrates by using the ultrasonically nebulized spray pyrolysis technique. Doping concentration of 1 %, 2 %, and 7 % of Sn, in V2O5 thin-films is studied by using metal–semiconductor-metal (MSM) based device structure. X-ray diffractometer (XRD) and field emission scanning electron microscope (FESEM) were used to analyze the surface morphology of the thin films. The XRD spectroscopic analysis shows the crystal size of above-mentioned samples, to be respectively 39 nm, 58 nm, 60 nm and 72 nm. The FESEM images showed the enhancement of crystal size with increase in Sn doping concentration. The optical properties of Sn doping on V2O5 thin film were studied by using UV–Vis spectrometer. The UV–Vis spectroscopic analysis shows that the absorption coefficient values decrease with increase in concentration of Sn metal doping in V2O5 thin film. The activation energies of all thin-film samples were calculated from Arrhenius plots and were found to be 0.938 eV, 1.101 eV, 1.11 eV and 1.169 eV, respectively, for all the thin-film samples mentioned above. The MSM based structure was fabricated by using a shadow mask and thermal evaporation. Later, the I-V characteristics of all the thin films were obtained by using semiconductor parameter analyzed at a biased voltage between −50 V and + 50 V with a step size of 1 V. Rectification ratio of the V2O5 films is significantly enhanced as the doping concentration increases. It was found that the rectification ratio of undoped V2O5 thin films increased linearly from 1.018 to 1.059 with an increase in temperature from room temperature to 130 °C. Similar trend was followed for 1 % (from 1.079 to 1.198), 2 % (from 1.081 to 1.224) and 7 % (from 1.095 to 1.311) Sn doped films. These results show the potential application of V2O5 thin films in the field of optoelectronics and thin film gas sensors.

The thermal stability of the γ-Fe2O3@SiO2 nanocomposites and super low friction of the γ-Fe2O3@SiO2 nanocomposite coatings in ambient air at high temperature are investigated in this paper. X-ray diffraction, scanning electron microcopy, transmission scanning electron microcopy, high-temperature tribometer, thermogravimetric analysis and differential scanning calorimetry were used to investigate the microstructure, surface morphology and high-temperature tribological properties of the γ-Fe2O3@SiO2 nanocomposite coatings, respectively. The results show that the γ-Fe2O3@SiO2 nanocomposite with the core–shell structure has excellent thermal stability because the SiO2 shell inhibits the phase transition of the γ-Fe2O3 phase to the α-Fe2O3 phase in the nanocomposites. The temperature of the phase transition in γ-Fe2O3 can be increased from 460 to 829 °C. The γ-Fe2O3@SiO2 nanocomposite coatings exhibit super low friction (0.05) at 500 °C. A high-temperature super low friction mechanism is attributed to γ-Fe2O3 and the tribochemical reactions during sliding.

GeFe2O4 (GFO) is a germanium mineral whose spinel crystal structure determines its interesting functional properties. Recently, it was proposed for application as an anode for Sodium and Lithium-Ion Batteries (SIBs and LIBs) thanks to its combined conversion and alloying electrochemical mechanism. However, its entire potential is limited by the poor electronic conductivity and volumetric expansion during cycling. In the present paper, pure and Sn or Mg doped GFO samples obtained from mechano-chemical solid-state synthesis and properly carbon coated were structurally and electrochemically characterized and proposed, for the first time, as anodes for SIBs. The spinel cubic structure of pure GFO is maintained in doped samples. The expected redox processes, involving Fe and Ge ions, are evidenced in the electrochemical tests. The Sn doping demonstrated a beneficial effect on the long-term cycling (providing 150 mAh/g at 0.2 C after 120 cycles) and on the capacity values (346 mAh/g at 0.2 C with respect to 300 mAh/g of the pure one), while the Mg substitution was less effective.

Fe/N-doped carbon (Fe-NC) is an excellent base-metal catalyst for use in an electrocatalytic oxygen reduction reaction (ORR) with high activity. In this paper, graphite phase carbon nitride (g-C3N4) was first obtained from the pyrolyzing of melamine, and then different proportions of FeCl3 were separately doped into g-C3N4 to further prepare the Fe-NC catalyst. The Fe-NC catalyst was applied in an ORR reaction, and the results show that the Fe-NC catalyst doped with 0.5 mmol FeCl3 possesses exceptional electrocatalytic performance, with an onset potential of 0.96 V and a half-wave potential of 0.81 V, which approaches that of a Pt/C catalyst. Meanwhile, the Fe-NC catalyst displays high stability and methanol resistance. The results supply a new way to prepare efficient ORR electrocatalysts.

This paper reports the detection of ferric ions (Fe ^3+ ) based on nitrogen and sulfur co-doped carbon quantum dots. These nitrogen and sulfur co-doped carbon quantum dots were synthesized via a hydrothermal route using northern Shaanxi potatoes as carbon sources and ammonium sulfate as nitrogen and sulfur sources. The quantum yields of the carbon quantum dots were found to be 16.96% and 4.23% with and without doping, respectively. The structural details, morphology, and optical properties of carbon quantum dots were analyzed using Fourier transform infrared spectroscopy (FT-IR), x-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), ultraviolet-visible absorption spectroscopy (UV–vis), and fluorescence spectroscopy. The as-prepared co-doped carbon quantum dots were utilized as a fluorescent probe for detecting Fe ^3+ ions, where the fluorescence intensity of carbon quantum dots was remarkably quenched in the presence of Fe ^3+ ions. A good linear relationship for Fe ^3+ ion detection was obtained from 0 to 500 μ mol/L with a detection limit as low as 0.26 μ mol/L. Furthermore, the proposed method also provided satisfactory results in the tap water.

GeFe2O4 (GFO), with its intriguing intercalation mechanism based on alloying–conversion reactions, was recently proposed as an anode material for sodium ion batteries (SIBs). However, drawbacks related to excessive volume expansion during intercalation/deintercalation and poor electronic conductivity enormously hinder its practical application in batteries. In this regard, some experimental strategies such as cation substitutions and proper architectures/carbon coatings can be adopted. In this paper, pure and Mn-doped GFO samples were prepared by hydrothermal synthesis. The doped samples maintained the spinel cubic structure and the morphology of pure GFO. The electrochemical tests of the samples, performed after proper carbon coating, showed the expected redox processes involving both Ge and Fe ions. The Mn doping had a positive effect on the capacity values at a low current density (about 350 mAh/g at C/5 for the Mn 5% doping in comparison to 300 mAh/g for the pure sample). Concerning the cycling stability, the doped samples were able to provide 129 mAh/g (Mn 10%) and 150 mAh/g (Mn 5%) at C/10 after 60 cycles.