Infrared detectors can be used for a variety of applications such as: using in fiber-optic communications. Conventional technology for IR detectors is using p-i-n structure based on GaAs compound. This paper reports on the design and modeling of an IR detector using a p-i-n GaAs structure. Comsol software is used to simulate the model and the detector is discussed for terminal current, dopant profile, and energy band diagram. Finally, we have studied electric field according to layer depth under thickness, bias voltage, and field magnitude. we analyzed the electronic and optic behavior of IR detectors simultaneously and detection spectrum was obtained in terms of wavelength. تفاصيل المقالة

In this paper, the structure of SAW has been studied. In previous work in SAW, materials such as lithium niobium, lithium tantalite and gallium nitride were used in the structure of SAW, and thus had a low operating frequency and the highest reported operating frequency was about 4 GHz. In this paper, aluminum nitride and gallium nitride in the SAW structure are used in combination. The electrodes used in the structure are also made of aluminum. Comsol software was used to simulate the structure, and for the structure, the operating frequency was 7.02 GHz.and this wave guide by this design have a better performance of another structures تفاصيل المقالة

A computational study based on first-principles calculations by supercomputers for nanoelectronic devices sometimes leads to results that can rarely be obtained in experimental laboratories with measuring tolerances. In this paper, therefore, we obtained the electronic, electrical, and optoelectrical properties of silicon p-n junction nanostructures by solving Non-Equilibrium Green’s Function (NEGF) using the first-order perturbation theory. We extracted the density of states (DOS), quantum carrier transport coefficient, IV-curve, and optoelectrical behavior by calculating the photocurrent and then plotted the light absorption spectrum. In the studied silicon nanostructure, light absorption is negligible for incident photon energy below 1 eV, and peak absorption occurs at 4 eV. In this research, the developed computational model paves the way for the study of nano-opto-electronic devices. تفاصيل المقالة

Using Photovoltaic systems is gradually expanded by increasing energy demand. Abundance and availability of this energy, has turned to one of the most important sources of renewable energy. Unfortunately, photovoltaic systems have two big problems: first, those have very low energy conversion efficiency (in act between 12 and 42 percent under certain circumstances). Second, the power produced by the solar cell depends on nonlinear conditions such as solar radiation, temperature and charge feature. According to this, received power maximum of photovoltaic cells depends on different non-linear variables, it is necessary to be continuously traced, as maximum received power of the cell (by controller). In this research, the increasing efficiency of photovoltaic systems has been investigated by using Maximum Power Point Tracking (MPPT) in two different modes contained connected to the Grid and disconnected from the grid with simulation by MATLAB software. The obtained results showed that the proposed technique is able to improve the current, voltage and power output of photovoltaic cells. تفاصيل المقالة