فهرست مطالب

Journal of Progress in Physics of Applied Materials
Volume:2 Issue: 1, Jun 2022

  • تاریخ انتشار: 1401/08/08
  • تعداد عناوین: 12
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  • A. S. Shamsipoor, MohammadMehdi Bagheri-Mohagheghi *, Elham Mokaripoor Pages 1-10

    Boron (B) is considered as an important impurity in semiconductor physics and optoelectronic devices, especially to produce p-type silicon (p-Si). In this paper, we investigate the effect of Boron doping on the structural, electrical, optical, and photo-sensitivity properties of tin oxide (SnO2) semiconductor thin films. Boron doped tin oxide (SnO2: B) thin films were deposited on glass substrates at Ts=500 ͦ C for different atomic concentration of x=[B/Sn] = 0, 0.02, 0.04, 0.08, 0.10, 0.20, 0.30, and 0.50 by spray pyrolysis technique.The results of X-ray diffraction (XRD) analysis show the tetragonal rutile SnO2 structure with orientation along the (211) plane. The films have polycrystalline structure with granular and island-like grains morphology by Field-Emission Electron Microscope (FE-SEM). The SnO2:B films have shown n-type conductivity and decreasing - increasing behavior of electrical resistivity with B-doping for x ≤ 0.04 and x> 0.04, respectively. Also, carrier concentrations were obtained in the order of 1018-1020 cm-3. Average optical transmittance of SnO2:B thin films changed in the range of 65% to 87% in the visible region and SnO2:B (x=0.08) sample has highest transmittance. The optical gap of films was obtained in the range of 3.47-3.87 eV. From the photoconductive results, the x=0.50 film has exhibited the most optical sensitivity under light radiation.

    Keywords: Semiconductor thin films, SnO2, Boron, Spray pyrolysis
  • MohammadSadegh Riahimadvar, Mehdi Tajaldini * Pages 11-14

    In this paper, the ablation threshold of several metals has been considered by analogize the characteristics such as: fluence, specific heat of vaporization, and deposited energy. Analytically, the results showed that the threshold ablation happens when copper surface is radiated by CO2 laser pulses. Experimental observations showed the evaporation for Al and Zn and ablation threshold on Cu as expectation. Thereby, the analytical results have been confirmed by the experimental observation, completely. Oxidation has been observed on Cu surface in phase of Cu2O, particle sizes are around 200nm. The scanning electron microscope (SEM) image from the radiated surface clearly showed the starting point of the ablation, while the separation not happened, yet. Thus, observation could be interpreted as the ablation threshold. Notably, it could be concluded as such: first, the ablation threshold happens on the interaction of pulsed CO2 laser with copper surface. Second, observation on mentioned threshold approves the possibility of Cu2O nanoparticles synthesis by nanosecond CO2 laser in free space without a reactor.

    Keywords: CO2 laser, Ablation threshold, Cu, Nanoparticle Cu2O
  • Roghayeh Cheraghchi, Masoud Rezvani Jalal *, Masoud Pishdast, Alireza Abdikian Pages 15-19
    In this paper, investigation and simulation of nanoparticles grown by laser ablation in a liquid (LAL) are studied. Firstly, the probable growth mechanisms including “hydrodynamic condensation” and “electrical charging” are introduced. Then, using the Orbital Motion Limited (OML) theory, governing differential equations of growth by electrical charging mechanism (without surface evaporation) are obtained in the absence of plasma drift motion. By numerical solving of the equations in the hot and high-density plasmas (typical of laser ablation in liquids), the growth of nanoparticles is simulated and the upper limit of its size is obtained. The results show that the size of nanoparticles, by electrical charging mechanism, cannot be more than 10 nm. In the continuation, a drift motion is added to the plasma ions up to 8 km/s which is typical of an expanding plasma in liquid phase ablation. Simulation results show that such a drift motion will cause the nano-particles to miss their spherical shapes and get a pine-like shape. It is concluded that if the growth of nano-particles really obeys the electrical charging mechanism then the shape of the obtained nano-particles in the plasma phase of the LAL should not be spherical but must be pine-like and rather larger.
    Keywords: Electrical charging, Growth mechanism, Ion drift motion, Laser ablation in a liquid (LAL), Orbital Motion Limited (OLM)
  • B. Sahaya Infant Lasalle *, T. Kamalesh, P. Karuppasamy, Muthu Senthil Pandian, P. Ramasamy Pages 21-25
    The organic single crystal of 1,2,3- benzotriazole 2-chloro 4-nitrobenzoic acid (BCNB) was successfully grown by slow evaporation solution method using methanol as a solvent. The single crystal X-ray diffraction was used to analyse the lattice cell parameters of the grown BCNB crystal. The cell and lattice parameters of the BCNB crystal confirms the formation of monoclinic crystal structure with the P21/n space group. The diffraction planes (h,k,l) were determined by the powder X-ray diffraction (PXRD), which is in good agreement with the corresponding CIF file. The BCNB crystal exhibits good optical transmittance in the entire visible region, which is evident from the UV-Visible-NIR analysis. The photoconductivity analysis exposes the negative photoconductive nature of BCNB crystal. The self-defocusing and reverse saturable absorption effects of the BCNB is evident from the Z-scan experiment, which is prescribed in closed and open apertures and these results were used to deduce the 3rd order NLO parameters like n2, β and (χ(3)).
    Keywords: Nonlinear optics, Single crystal, PXRD, UV-Visible-NIR, Z-scan
  • Mohamad Mansouri *, Hamid Rezagholipour Dizaji, MohammadReza Saeidi, Majid Vaezzadeh Pages 27-34

    Experimental results show that there are uninterpreted physical phenomena in the resistivity behavior of carbon nanotubes (CNT) in terms of their diameter changes. In this paper, a model based on previously published empirical data is created. This model is used later to analysis the effect of repulsion on electron transport throughout CNT. The relationship between the resistivity and the diameter of CNT, with an introduced parameter named 'electron gas hardness' has theoretically investigated. The results show an acceptable theoretical model for the behavior of electrical resistivity to reduce the diameter of nanotubes and is predicted by physico-mathematical calculations. Furthermore, a detailed analysis of the temperature effects on the transport properties in CNT and how compare to electron-phonon interactions that have been shown to affect resistivity and a theoretical model of electrical resistivity to changes of two important parameters of diameter and temperature of carbon nanotubes, physical formulation and modeling is presented.These results are consistent with the experimental results and are generalized.

    Keywords: Carbon nanotubes, Electron Gas Repulsion, Resistivity, Mean Free Time, Critical Diameter
  • Sanaz Alamdari *, Maryam Haji Ebrahimi, Omid Mirzaee, Majid Jafar Tafreshi, MohammadHosein Majlesara, Mohammad Tajali, Morteza Sasani Ghamsari, Aghil Mohammadi Pages 35-40

    TLDs (thermoluminescent dosimeters) and ionizing ray sensors are well-known and essential instruments in a variety of medical fields. This work reports the investigation of structural, optical, and thermoluminescence (TL) properties of the Ce: CdWO4 and Ce: WO3 nanopowders prepared by the co-precipitation method. XRD and EDX-elemental mapping analyses were performed in order to confirm the crystalline phase and the presence of the elements in the synthesized samples. FESEM images showed that the 70 nm diameter spheroid-like particles and 204 nm diameter cubic-like particle were found in the Ce: CdWO4 and Ce: WO3 samples, respectively. The TL measurement was done by exposing the produced pellets to a gamma source. Prepared powders showed strong blue-green emissions at room temperature and a strong TL peak at 350-450 °C under UV and gamma-ray excitation respectively. Obtained results indicate that the nanopowders produced in this work have the potential for use as thermo/photoluminescent materials in photonic devices and detectors.

    Keywords: luminescence, CdWO4, Ce dopant, Ionizing ray sensor, Thermoluminescence
  • Shadi Esmaeili *, Mustafa Aghazadeh, Isa Karimzadeh, Fatemeh Shokrian Pages 41-47
    In this study, the effect of different substitutions (Eu, Ce, Al, and Bi) on the structural and magnetic properties of Fe3O4 is investigated. All samples were synthesized with the cathodic electrochemical deposition method. The structural properties and surface morphology are investigated by  XRD and FESEM analyses. Structural analysis of the samples showed the formation of a single-phase structure with an Fd-3m space group. The results also showed that the lattice constant and the cell volume increase by increasing the substituted ion's radius. The results of surface morphology of the samples also showed that with increasing substituted ion radius, the average diameter of the samples increases. For BiFe2O4, EuFe2O4, CeFe2O4, and AlFe2O4 samples, the mean diameter was obtained at 50.038 (±13.60)nm, 47.95 (±9.62)nm, 36.06 (±8.29)nm, and 45.72 (±5.39)nm, respectively. And, the magnetic properties of the samples were investigated by VSM analysis. The study of the magnetic properties of the samples shows the superparamagnetic behavior for all samples. Also, the results show that substituting Fe ions with larger radii ions leads to a decrease in saturation magnetization (Ms) and residual magnetization (Mr).
    Keywords: Fe3O4 ferrite, Substitutions, Cathodic electrical deposition method, Magnetic properties
  • Leila kafi ahmadi, shahin khademinia Pages 49-56

    Synthesis of Cu2V2O7 nanoparticles was performed successfully using Cu(NO3)2 and V2O5 raw compounds in one step solid state method. Cu2V2O7 nano powders were used as photocatalysts to remove pollutant dye under visible light irradiation. X-ray diffraction (XRD) technique was applied to characterize the crystal phase type of the as-prepared sample. The XRD results showed that the patterns had a main Cu2V2O7 structure with a space group of C2/c. Field emission scanning electron microscopy (FESEM) images showed that the synthesized Cu2V2O7 particles had mono-shaped sphere morphologies. The as-prepared Cu2V2O7 nanomaterial exhibited high catalytic activity in multi-component reaction for the one-pot synthesis of heterocyclic compound 3,4-dihydropyrimidin-2(1H)-ones (DHPMs). Additionally, the nanocatalyst can be reused for several times without apparent loss of its catalytic activity, confirming it is a highly stable and reusable material for this reaction. It is found that the optimum values for catalyst amount, reaction time and temperature are 50 mg, 50 min and 90 ºC, respectively.

    Keywords: Copper pyrovanadate, Solid state, Nanomaterial, Catalyst, Biginelli
  • sepideh pazouki, Nafiseh Memarian Pages 57-61

    In this article, tin oxide nanoparticles were prepared by hydrothermal method and then deposited on fluorine doped tin oxide(FTO) glass by Dr. Blade method and dye sensitized solar cell (DSSC) was fabricated with tin oxide photoanode. To improve cell efficiency, the prepared photoanode was doped with titanium and the effect of Ti doping on physical properties and performance of DSSCs were investigated. The physical properties of the synthesized nanostructures were investigated by XRD, SEM, BET, and DRS analyses. Finally, DSSC solar cells were constructed from prepared photoanodes and current-voltage analysis was performed. The results showed that Ti doping affects the adsorption-desorption isotherm of the sample and increases the specific surface area significantly. Thus, specific surface area has increased from 36.23 m2/g for the SnO2 sample to 508.13 m2/g for the Ti doped sample. The results showed that the DSSC made with doped photoanode showed much better performance and titanium doping increased both the short circuit current and open circuit voltage. The titanium doped sample showed an increase in efficiency of about 2 times compared to the pure SnO2 photoanode.

    Keywords: Dye sensitized solar cell, Nanoparticles, Tin oxide, Titanium doping
  • samira hadilou, mahdi behzad, shahin khademinia Pages 63-69

    Yb2V2O7 nano-powders were synthesized via solid state and hydrothermal reactions using Yb2O3 and Na2VO4 at stoichiometric 1:1 Yb:V molar ratio as raw materials for the first time. The synthesized materials were characterized by powder X-ray diffraction (PXRD) technique. Structural analysis was performed by FullProf program employing profile matching with constant scale factors. The results showed that the patterns had a main Yb2V2O7 structure with a space group of . Besides, the data revealed that the reaction conditions affected the physical property and crystal phase growth of the obtained materials. FESEM images showed that the synthesized Yb2V2O7 particles had mono-shaped sphere morphologies. Ultraviolet–visible spectroscopy (UV-Vis) analysis showed that the nanostructured Yb2V2O7 powders possessed strong light absorption properties in the ultraviolet-visible light region. The direct optical band gaps were 3.90, 4.10, 4.15, and 4.35 eV for S1, S2, S3, and S4, respectively. Electrochemical property of Yb2V2O7 nanoparticle was studied by cyclic voltammetry (CV) technique in NaOH electrolyte medium.

    Keywords: Yb2V2O7, Hydrothermal Method, Nanomaterial, Solid State Method, Cyclic Voltammetry
  • Seiyed HamidReza Shojaei, Mahmoud Oloumi Pages 71-75

    The lattice-matched system (GaAs)n/(AlAs)n superlattice is calculated for two different values of n=3 and 6 within ab initio pseudopotential density-functional theory using Quantum Espresso package of program exploiting the ultra-soft atomic pseudopotentials. Their band offsets, which is a well-known and inextricable problem at semiconductor interfaces, have been determined in this paper and were compared with experimental results. Discontinuities of valance and conduction bands were obtained as 0.46 and 0.25 eV, respectively. The averaged self-consistent potential across the [001] interface in GaAs is about 0.061 eV higher than its value in AlAs. The local density of states for both superlattices was also studied. The effect of different factors e.g. orientation, transitivity, and composition dependence is reported in this study. We found that, in the [110] direction of GaAs/AlAs superlattice, the dependence of the band offset on the orientation is negligible. The calculated band gap of is linearly dependent on aluminum content.

    Keywords: Nanosemiconductors, Density functional theory, Band discontinuities, Pseudopotential, Local density of States
  • shiva salehi, Mustafa Aghazadeh, Isa Karimzadeh Pages 77-82

    A Zn-based metal–organic framework (Zn-MOF) was synthesized by a novel electrodeposition method. The prepared Zn-MOF was characterized using powder X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy techniques. The supercapacitive behavior of synthesized MOF was examined using cyclic voltammetry (CV), galvanostatic charge/discharge, and electrochemical impedance spectroscopy (EIS) measurements in 3 M KOH. SEM images confirmed that Zn-MOF is composed of layered cuboid structure properly attached on to nickel foam substrate. Electrochemical behaviors of the Zn-MOF/Ni foam were also evaluated through GCD tests, which showed high specific capacitance of 288 F g–1 at the current density of 2 A g–1. The outcomes showed great potential of fabricated Zn-MOF as a high-performance electrode material for electrochemical supercapacitors.

    Keywords: Electrodeposition, Energy storage, conversion, Metal-Organic-Frameworks, Specific capacitance