Journal of Interfaces, Thin Films, and Low dimensional systems
https://jitf.alzahra.ac.ir/
Journal of Interfaces, Thin Films, and Low dimensional systemsendaily1Mon, 01 Mar 2021 00:00:00 +0330Mon, 01 Mar 2021 00:00:00 +0330An evaluation for CIGS based thin-film solar cells development
https://jitf.alzahra.ac.ir/article_6130.html
This review summarizes the current status of chalcopyrite CIGS thin film solar cell technology with a focus on recent advancements and emerging concepts intended for higher efficiency and novel applications. The recent developments and trends of research in labs and industrial achievements communicated within the last years are reviewed and the major developments linked to alkali post deposition treatment and composition grading in CIGS, surface passivation, buffer and transparent contact layers are emphasized. In recent years, a lot of efforts have been initiated to develop low-cost thin-film solar cells, which are alternatives to high-cost silicon (Si) solar cells. Copper Indium Gallium Selenide (CIGS) based solar cells have become one of the most promising candidates among the thin film technologies for solar power generation. The current record efficiency of CIGS has reached 22.6%, which exceeds the current multi crystalline Si record efficiency (21.9%). However, material properties and efficiency on small area devices are crucial aspects to be considered before manufacturing into large scale. Chalcopyrite-based solar cells were first developed using CuInSe_2 absorber material, but it was quickly become dependent on the [Ga&frasl;((In+Ga)]) ratio.Thermal entanglement in spin chain with XX, XY, and XZ Heisenberg interaction
https://jitf.alzahra.ac.ir/article_6131.html
In this paper, the quantum correlation of the 2- spin Heisenberg model systems with Dzyaloshinskii-Moriya interaction and in the presence of the external magnetic field is studied. Three types of the exchange interaction, XX, XY, and XZ interactions are considered . The thermal entanglement of these systems is investigated under the change of the external magnetic field. We found that the temperature behavior of three models is similar, although the critical temperature is different. Also, we investigated the effect of the external magnetic field on the negativity of the system. We observed that all three models have the critical magnetic field in which the negativity of the system becomes zero. In fact, the anisotropic Heisenberg interaction can affect the critical temperature and critical magnetic field of the two- spin systems.DFT study of Silicon channel effects embedded between armchair graphene nanoribbons with different widths on mechanical and electronic properties
https://jitf.alzahra.ac.ir/article_6133.html
Graphene Nano-Ribbons (GNR) are strong candidates for future materials in the electronics industry. In this paper, we extract the mechanical and electrical properties of AGNRs combination of different widths and deposition of silicon dimer to create Metal-insulator-semiconductor by the DFT method. Results demonstrate that by decreasing the mean width and strain of AGNR-AGNR composite and replacing the carbon dimer with silicon dimer, the bandgap of the system will reduce. The AGNR-Si-AGNR composite is a promising candidate for transistor application due to the small bandgap and high current flow allowance due to the high near the Fermi&rsquo;s level electronic state involvement under the bias voltage.Effect of vacancy defects on the Josephson current in zigzag graphene narrow strips
https://jitf.alzahra.ac.ir/article_6132.html
We investigate the Josephson current in a superconductor/zigzag graphene narrow strip/superconductor (Sc-ZGNS-Sc) junction, with vacancy defects. For this purpose, we extend a recursive Green&rsquo;s function based numerical method to ZGNSs and take into account the effect of vacancies including random single vacancy distributions and also chain-like linear defects. We investigate how the Josephson current is affected by the length and the width of the strip and the concentration of the vacancies. We find that the Josephson current exhibits an exponentially dependence on the vacancy concentration. The exponent coefficient is a nonlinear function of the length of the lattice and the vacancy concentration. For the width dependence we find a linear relation between the Josephson current and the width of the ZGNS which propose a semi classical treatment of the electron transport in this system. Finally, we study the effect of chain-like linear defects and compare them with randomly distributed single vacancies.Optimization of electron scattering from random potential barriers on the surface of topological insulators
https://jitf.alzahra.ac.ir/article_6155.html
Optimization of electron scattering has been investigated using random potential barriers. Random pottential barriers can be defined in two ways: when these line defects are placed on the insulation surface, but strength of their potential is changing randomly, and the other is when potential barriers have a constant value, while their location on the surface of topological insulators is changing randomly. To observe the better passage of electrons, the probability of transmission in the random potential state is calculated N times. These N values are averaged and with the probability of transmission, in the local potential state is compared. It seems that, to propagating of incident electron for some amount of incident energy, the number of defects, strength of potential and even direction of propagation electron, to the same result for the local line defects is close. But for some amounts of incident energy or some structural changes show significant changes.Electrical properties of magnetic tunnel junctions affected by two types of interfacial roughness
https://jitf.alzahra.ac.ir/article_6156.html
The theoretical study has been done for investigating the effect of two types of rough interfacials on the electrical properties of a the magnetic tunneling structures. Surface roughness is found to have a strong influence on the spin polarized transport throughmagnetic tunneling junctions . The scattering mechanism because of rough interfaces causes to reduction of maximum achievable value of transmission probability resonance. Also, the presence of roughness interfacial causes to change in the spin polarization and the tunneling magnetoresistance ratios. The asymmetry distribution of the density of states may be reduced and the spin polarization and the tunneling magnetoresistance show the irregular behavior.Temperature effect on femto-dimensional bound states
https://jitf.alzahra.ac.ir/article_6209.html
The bound state of exotic gluons with a thermal background in the framework of the projective unitary representation in the physics model at high energy interactions has been investigated. The ground and excited states of gluonic systems to describe the temperature effect of the mass spectrum have been defined. The problem of calculating the mass spectrum of coupled states based on the QFT in its broadest sense is a technique, to detect and obtain reasonable objectives and goals. The aim of this paper is to present the possible use of symplectic space in Femto-dimensional bound states at a finite temperature within strong interaction. The results can be used for describing nonzero and zero temperature mass spectra of mesons and multigluon-bound states. The problem of determining coupled state masses based on the polarization function is examined in detail. The Hamiltonian of the interaction and the structure of the bound state with the Schr&ouml;dinger equation within the color-confining potential and Debye mass at finite temperature is presented and then the mass spectrum of a glueball at high energy interaction is determined. The mass spectrum of a two-gluon coupled state is calculated. The results are presented in the figures and table.Interface roughness scattering effect on electrical properties of heterojunctions
https://jitf.alzahra.ac.ir/article_6266.html
In the present work, the effect of roughness in resonant tunneling diodes have been considered to track two main goals. At first, the roughness impact on the transport through these heterojunctions has been studied, and then roughness type effect have been also investigated. For calculating the electrical transport, the transfer matrix technique has been used in simulations. Two different standard methods of deposition - Random deposition (RD), and Ballistic deposition (BD)- have been applied to generate two dissimilar rough interfaces. The scattering process cause to reduction of transport probability. The conductivity as a function of voltage has been also calculated. Effect of interface roughness on the peak-to-valley current ratio in the presence of roughness have been discussed. The results show that the scattering affect it significantly. As the applied voltage increase, at first, the value of current reaches to maximum amount, and then with increasing the voltage, the current falls in a negative differential resistance region.