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This article studies the combined effect of spatial heterogeneity and capillary pressure on the saturation of two fluids during the injection of immiscible nanoparticles. Various literature review exhibited that the nanoparticles are helpful in enhancing the oil recovery by varying several mechanisms, like wettability alteration, interfacial tension, disjoining pressure and mobility control. Multiphase modelling of fluids in porous media comprise balance equation formulation, and constitutive relations for both interphase mass transfer and pressure saturation curves. A classical equation of advection-dispersion is normally used to simulate the fluid flow in porous media, but this equation is unable to simulate nanoparticles flow due to the adsorption effect which happens. Several modifications on computational fluid dynamics (CFD) have been made to increase the number of unknown variables. The simulation results indicated the successful transportation of nanoparticles in two phase fluid flow in porous medium which helps in decreasing the wettability of rocks and hence increasing the oil recovery. The saturation, permeability and capillary pressure curves show that the wettability of the rocks increases with the increasing saturation of wetting phase (brine).

An extended short-wavelength nBn InAs/GaSb/AlSb type-II superlattice-based infrared focal plane array imager was demonstrated. A newly developed InAs_0.10Sb_0.90/GaSb superlattice design was used as the large-bandgap electron barrier in this photodetector. The large band gap electron-barrier design in this nBn photodetector architecture leads to the device having lower dark current densities. A new bi-layer etch-stop scheme using a combination of InAs_0.91Sb_0.09 bulk and AlAs_0.1Sb_0.9/GaSb superlattice layers was introduced to allow complete substrate removal and a shorter wavelength cut-on. Test pixels exhibit 100% cutoff wavelengths of ∼2.30 and ∼2.48  μm at 150 and 300 K, respectively. The devices achieve saturated quantum efficiency values of 59.7% and 63.8% at 150 and 300 K, respectively, under backside illumination and without any antireflection coating. At 150 K, photodetectors exhibit dark current density of 8.75×10^−8  A/cm^2 under −400  mV applied bias, providing specific detectivity of 2.82×10^12  cm·Hz^1/2/W at 1.78 μm. At 300 K, the dark current density reaches 4.75×10^−2  A/cm^2 under −200  mV bias, providing a specific detectivity of 8.55×10^9  cm·Hz^1/2/W 1.78 μm.

A versatile infrared imager capable of imaging the near-visible to the extended short-wavelength infrared (e-SWIR) is demonstrated using e-SWIR InAs/GaSb/AlSb type-II superlattice-based photodiodes. A bi-layer etch-stop scheme consisting of bulk InAs_0.91Sb_0.09 and AlAs_0.1Sb_0.9/GaSb superlattice layers is introduced for substrate removal from the hybridized back-side illuminated photodetectors. The implementation of this new technique on an e-SWIR focal plane array results in a significant enhancement in the external quantum efficiency (QE) in the 1.8–0.8 μm spectral region, while maintaining a high QE at wavelengths longer than 1.8 μm. Test pixels exhibit 100% cutoff wavelengths of ∼2.1 and ∼2.25  μm at 150 and 300 K, respectively. They achieve saturated QE values of 56% and 68% at 150 and 300 K, respectively, under back-side illumination and without any anti-reflection coating. At 150 K, the photodetectors (27  μm×27  μm area) exhibit a dark current density of 4.7×10^−7  A/cm^2 under a −50  mV applied bias providing a specific detectivity of 1.77×10^12  cm·Hz^1/2/W. At 300 K, the dark current density reaches 6.6×10^−2  A/cm^2 under −50  mV bias, providing a specific detectivity of 5.17×10^9  cm·Hz^1/2/W.

The present study demonstrates an innovative single-step thermal synthesis of nano-sized lithium tetraborate dosimeter and its characterization. The optimum calcination temperature and time for the synthesis of the nanoparticles material was 750°C and 2h, respectively. Characterization of the samples was carried out using X-ray diffractometry (XRD), Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), and thermoluminescence (TL). FT-IR, XRD and TEM results confirmed the formation of pure nano-crystalline lithium tetraborate. The product showed a linear response over a wide range of doses from 10−1to 1.5×102Gy. Moreover, the samples illustrate non-energy dependence among a wide range energy interval from 24keV up to 1250keV and almost no fading during one month storage.

This study includes the synthesis of nano-sized lithium tetraborate by an innovative single step thermal treatment method and characterization of the products. The heating temperature for the synthesis was varied between 200 and 850°C with the retention time of 2h. Polyvinyl pyrrolidone (PVP) with different concentrations was used as surfactant. Characterization of the samples was achieved by thermogravimetric analysis (TGA), derivative thermogravimetry analysis (DTG), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM) techniques and UV–vis spectroscopy. Thermal analysis of initial solution allowed the optimization of the heat treatment program and showed that the thermal stability of samples is started at 460°C. FT-IR, XRD and TEM results proved the formation of pure nano-crystalline lithium tetraborate at temperature between 460 and 750°C. Furthermore, the band gap investigation was performed using UV–vis spectra in the presence of different concentrations of PVP and in variety of calcination temperatures. The estimated optical bandgap was found to be between 5.2 and 6.2eV.

The spark of aggressive scaling of transistors was started after the Moors law on prediction of device dimensions. Recently, among the several types of transistors, junctionless transistors were considered as one of the promising alternative for new generation of nanotransistors. In this work, we investigate the pinch-off effect in double gate and single gate junctionless lateral gate transistors. The transistors are fabricated on lightly doped (1015) p-type Silicon-on-insulator wafer by using an atomic force microscopy nanolithography technique. The transistors are normally on state devices and working in depletion mode. The behavior of the devices confirms the normal behavior of the junctionless transistors. The pinch-off effect appears at VG +2.0 V and VG +2.5 V for fabricated double gate and single structure, respectively. On state current is in the order of 10-9 (A) for both structures due to low doping concentration. The single gate and double gate devices exhibit an Ion/Ioff of approximately 105 and 106, respectively.

In this work, we have investigated the fabrication of Double gate and Single gate Junctionless silicon nanowire transistor using silicon nanowire patterned on lightly doped (105 cm-3) p-type Silicon on insulator wafer fabricated by Atomic force microscopy nanolithography technique. Local anodic oxidation followed by two wet etching steps, Potassium hydroxide etching for Silicon removal and Hydrofluoric acid etching for oxide removal, were implemented to reach the structures. Writing speed and applied tip voltage were held in 0.6 µm/s and 8 volt respectively for Cr/Pt tip. Scan speed was held in 1.0 µm/s. The etching processes were elaborately performed and optimized by 30%wt. Potassium hydroxide + 10%vol. Isopropyl alcohol in appropriate time, temperature and humidity. The structure is a gated resistor turned off based on a pinch-off effect principle, when essential positive gate voltage is applied. Negative gate voltage was unable to make significant effect on drain current to drive the device into accumulation mode.

Type-II InAs/GaSb superlattices (T2SLs) has drawn a lot of attention since it was introduced in 1970, especially for infrared detection as a system of multi-interacting quantum wells. In recent years, T2SL material system has experienced incredible improvements in material quality, device structure designs and device fabrication process, which elevated the performances of T2SL-based photo-detectors to a comparable level to the state-of-the-art material systems for infrared detection such as Mercury Cadmium Telluride (MCT). As a pioneer in the field, center for quantum devices (CQD) has been involved in growth, design, characterization, and introduction of T2SL material system for infrared photodetection. In this review paper, we will present the latest development of bias-selectable multi-band infrared photodetectors at the CQD, based on InAs/GaSb/AlSb and InAs/InAs1-xSbxtype-II superlattice.

We report the substrate transfer of InAs/GaSb/AlSb based type-II superlattice (T2SL) e-SWIR photodetector from native GaSb substrates to low-loss sapphire substrate in order to enhance the frequency response of the device. We have demonstrated the damage-free transfer of T2SL-based thin-films to sapphire substrate using top-down processing and a chemical epilayer release technique. After transfer the ?3 dB cut-off frequency increased from 6.4 GHz to 17.2 GHz, for 8 ?m diameter circular mesas under ?15 V applied bias. We also investigated the cut-off frequency verses applied bias and lateral scaling to assess the limitations for even higher frequency performance.

We fabricated ?-Ga2O3:Si metal-oxide field-effect transistors (MOSFETs) on c-plane sapphire substrates which typically showed maximum drain current of 100 mA mm?1. ?-Ga2O3:Si thin films were realized on c-plane sapphire substrates through a combination of metalorganic chemical vapor deposition and post-annealing. The MOSFET device presented excellent on/off drain current ratio of ?1011with very low gate leakage current, sharp pinch off behavior, and a breakdown voltage of 400 V at VG= ?40 V. The growth and fabrication of ?-Ga2O3:Si MOSFETs on c-plane sapphire is valuable to its demonstration of the great potential for future high-power electronic devices.

We fabricated b-Ga2O3:Si metal-oxide field-effect transistors (MOSFETs) on c-plane sapphire substrates which typically showed maximum drain current of 100 mA mm[?]1. b-Ga2O3:Si thin films were realized on c-plane sapphire substrates through a combination of metalorganic chemical vapor deposition and post-annealing. The MOSFET device presented excellent on/off drain current ratio of [?]1011 with very low gate leakage current, sharp pinch off behavior, and a breakdown voltage of 400 V at VG = [?]40 V. The growth and fabrication of b-Ga2O3:Si MOSFETs on c-plane sapphire is valuable to its demonstration of the great potential for future high-power electronic devices.