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Pure and Al doped nanocrystalline ZnO films have been prepared on Hydrogen terminated Si(100) substrates by nebulized spray pyrolysis. The dependence of the structural, compositional and electrical properties were investigated using XRD, EDX, AFM and spectrophotometer. The X-ray diffraction data coincide well with the pattern of ZnO reported with the Standard Database. Films annealed at higher temperatures show better orientation, as revealed from X-ray diffraction patterns. Annealing the films in air improved the electrical properties. From the I-V characteristics, the nonlinear coefficient α value has been estimated. Reflectance measurements show good reflectance in the IR region for pure ZnO films, and Al doping improved the reflectance values.

The quantum transport in the Superconductor–Semiconductor (S–Sm) mesoscopic interface is investigated in the presence of an external electromagnetic field by suggesting a Maxwell potential at the interface. We analyze the current spectrum as a function of the frequency and the distance between the superconductor electrodes. The current displays oscillations with an amplitude that shows a strong dependence on the photon frequency, the field intensity dependence of the current can give direct information of the lead–semiconductor interface energy spectra.

We have numerically investigated electronic transport properties in single-walled carbon nanotubes (SWCNTs) doped with boron (B) and nitrogen (N) substitutional impurities. Our calculations are performed by the ab initio density functional theory (DFT) and the nonequilibrium Green's function (NEGF) approach. We show that the electronic transmissions are moderated after the doping on both metallic and semiconducting CNTs. In B and N codoping nanotubes, depending on the arrangements of B and N substitutions, electronic and transport properties have been also modified. Calculating from electronic transmissions under bias, I–V characteristics of doped CNTs are demonstrated. In our simulations, we find that the substituting impurities in the semiconducting CNT raise the conductivity regardless of p- or n-type doping, whereas the conductivity of metallic CNTs is reduced by doping.

In this paper, ZnO nanorods were grown by wet chemical method on p-Si (100) substrate to form n-ZnO nanorods/p-Si (100) heterojunction. The optical, electrical, structural properties of n-ZnO nanorods/p-Si(100) heterojunction were analyzed by the photoluminescence (PL) spectroscopy, $I$–$V$ measurement, X-ray diffraction (XRD) and scanning electron microscope (SEM), respectively. The room temperature PL spectra reveal the good optical property of the heterojunction with strong UV peak at 385nm. The ZnO nanorods were vertically well-aligned on p-Si (100) and had an average height of about 1.6$\mu$m. The n-ZnO nanorods/p-Si (100) heterojunction also exhibits diode-like-rectifying-behavior.

In this study, the effects of introducing a zinc cation into a zinc-phthalocyanine (ZnPc) cluster are examined in relation to organic phthalocyanine material. The Au/ZnPc/Si-based organic diode is made using the thermal evaporation method. The optical properties of the filter are checked and a selected wavelength of 360nm is recorded. Au/ZnPc/Si/Al exhibits high rectifying performance, and the organic device’s primary conduction mechanism is Space Charge Limited Current. ZnPc film’s superior transparency is shown in the visible spectrum, and its optical bandgap of 3.32eV is found. According to this result, ZnPc is a semiconductor. ZnPc has a weak exciton binding energy (600meV), a high chemical stability, and non-zero value of second hyperpolarizability (4.7310${}^{-36}$esu). These features can offer our ZnPc-based organic device a wide range of applications, including microelectronics, solar cells, and nonlinear optical devices.

The photopatterning process of self-assembled monolayer has been used as template for fabricating biomolecular microstructures. Alkanethiolates formed by the adsorption of 1-octanethiol molecules on a gold substrate were oxidized by the irradiation of deep UV light and then developed with deionized water. The resulting positive patterned substrate was immersed into a dilute ethanolic solution of 11-mercaptoundecanoic acid (11-MUDA). Cytochrome c monolayers were immobilized onto the patterned gold substrate by self-assembly technique and their electrochemical properties were investigated through the measurements of cyclic voltammetry. Also, I–V characteristics of biomolecular multilayers consisting of cytochrome c and green fluorescent protein (GFP) were studied with a scanning tunneling microscope (STM).

Dye-sensitized solid-state solar cells (DSSC) based on n-type ZnO and p-type CuSCN have been fabricated with highest recorded power conversion efficiency. The working electrode of the cell is composed of D149 dye-coated ZnO-based interconnected nanoparticulate (20 nm) mesoporous layer with ZnO-based dense layer which was prepared on fluorine-doped tin oxide (FTO) glass substrates. CuSCN deposition was carried out according to the previously reported procedure which ensures enhanced p-type conductivity of CuSCN. The surface morphologies of the ZnO dense layer, ZnO porous layer and CuSCN layer have been visualized using scanning electron microscopy (SEM). The cells were fabricated with the configuration of FTO/ZnO dense layer/ZnO porous layer/D149/CuSCN/Graphite/Cr-coated FTO. Then the cells were characterized using I-V data as functions of the dense layer resistance (which is proportional to the thickness of the dense layer) and the porous layer thicknesses. The optimum dense layer is found to have 1500 Ω/□ sheet resistance. The cell with porous layer thickness of 9 μm at this dense layer resistance shows the maximum power conversion efficiency of 2.28%. The solar cell parameters of this optimized cell are an open circuit voltage of 0.55 V, a fill factor of 0.51 and a short-circuit current density of 8.2 mA cm^-2.

The role of Cl and H atoms inside AlPc organic molecule by experimental, DFT, and TD-DFT methods is investigated. A detailed study of Pc, AlPc-Cl, and AlH-Pc absorption wavelengths, energies, and oscillator strengths are achieved. To strengthen such investigation, HOMO-LUMO and DOS spectrum analysis are described showing the optical band of 2.01, 2.11, and 2.18 eV for Al-Pc, AlH-Pc, and AlCl-Pc compounds respectively, and nonlinear optical properties are presented. Furthermore, the values of calculated dipole moment, polarizability, and second-order static hyperpolarizability of AlCl-Pc, AlH-Pc, Al-Pc, and Pc compounds are studied. The heterojunctions based on AlPc-Cl and AlPc-H are fabricated by low-cost routes. I-V characteristics are demonstrated under dark and room temperatures. A high rectifying ratio of our heterostructures based on AlPc is exhibited. Non-ideal behavior, $n>$ 1, of the fabricated heterostructures due to the presence of interface states is revealed.

The control of ionic transportation inside the multi asymmetric conical nanopores in polyethylene terephthalate (PET) membrane was investigated. The conical nanopores were prepared by chemical etching in irradiated PET foil using etchant (9 M NaOH) and stopping solution (1 M NaCl $+$ 1 M HCOOH). The behavior of ionic current was recorded under stepping voltage $-$2V to $+$2V at different molar concentrations of potassium halides (KCl, KBr and KI) under symmetric bathing condition in electrochemical cell. It is found that the presence of multiple ionic species and the occurrence of counterion condensation of charge regulated polyelectrolyte play an effective role in ionic current rectification (ICR). The electrical conductance of conical nanopores may be estimated by measuring the ionic current rectification properties of track-etched nanopores. The charge transport properties vary with molar concentration and pH of electrolyte. Moreover, ICR may be used as a voltage gating phenomena with wide technological applications.

This paper presents the effect of dielectric materials i.e., hafnium dioxide (HfO₂, high-$k)$ and silicon dioxide (SiO₂, low-$k)$, as gate-oxide material for the nonaligned double gate junction $n$-channel field effect transistor (NADG-NFET). The NADGNFET device proposed in this work lowers the second order effects and improves the transistor linear performance at radio frequency. The device response with gate-oxide material is investigated by using two dielectric materials on the obtained current–voltage characteristics, intrinsic gain, and linearity parameter. The device simulations were done using a 2D-sentaurus TCAD tool. The results were examined in terms of DIBL (drain-induced barrier lowering), SS (subthreshold swing), $I_{\mathrm{\text{ON}}}$ current, $I_{\mathrm{\text{ON}}}/I_{\mathrm{\text{OFF}}}$ ratio, the Intrinsic gain ($A_{\mathrm{\text{VO}}})$, and intermodulation distortion power-3 (IMD3) parameter. It has been found that high-$k$ dielectric decreases the DIBL by 40%, improves the $I_{\mathrm{\text{ON}}}/I_{\mathrm{\text{OFF}}}$ ratio by 8 times, and also improves the intrinsic gain by 38% compared to low-$k$ dielectric material. However, the high frequency parameter result was better with low-$k$ dielectric material. This gives a trade-off in the device applications. The IMD3 plot shows that using the two gate-oxide material will give the same performance to the radio frequency (RF) signal.

Nanocrystalline ruthenium (Ru)-doped ZnO thin films on sapphire substrate was prepared using sol–gel method by spin coating technique. The structural and I-V characteristics of Ru doped ZnO thin films were studied from the X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) analysis and Raman spectroscopy. X-ray diffraction (XRD) results revealed that the deposited films belonged to hexagonal wurtzite structure with c-axis orientation. It is also confirmed from the Raman spectra. Enhancement of longitudinal optical (LO) phonon is observed by the strong electron–phonon interaction. An observed increment in sheet resistance with increase in dopant percentage of Ru (1–2mol%) in ZnO films was found and better I-V characteristic behavior was observed at 1mol% of Ru-doped ZnO thin films. Trap limited current flow inside the material was calculated from the log I versus log V plot in the higher voltage region.

The photopatterning process of self-assembled monolayer has been used as template for fabricating biomolecular microstructures. Alkanethiolates formed by the adsorption of 1-octanethiol molecules on a gold substrate were oxidized by the irradiation of deep UV light and then developed with deionized water. The resulting positive patterned substrate was immersed into a dilute ethanolic solution of 11-mercaptoundecanoic acid (11-MUDA). Cytochrome c monolayers were immobilized onto the patterned gold substrate by self-assembly technique and their electrochemical properties were investigated through the measurements of cyclic voltammetry. Also, I–V characteristics of biomolecular multilayers consisting of cytochrome c and green fluorescent protein (GFP) were studied with a scanning tunneling microscope (STM).