Papers by Keyword: Semiconductor

Abstract: This paper presents system performance indices for a class-B power amplifier using Double-Gate (DG) Metal Oxide Semiconductor Field Effect Transistor (MOSFET). It also presents a comparative analysis of three power amplifiers using different switching devices, i.e. Bipolar Junction Transistor (BJT), MOSFET, and DG MOSFET. The MOSFET used in this research work is based on Silicon for n-MOSFET and SiO₂ has been used as oxide layer. These power amplifiers are also being designed and simulated to test the speed and time (taken for each of these power amplifiers) to get the output signal when an input signal is applied. A comparison of these three power amplifier circuits is taken in the tabular form to conclude which power amplifier circuit performs better regarding its switching speed and the time. Switching speed relates with the time taken to amplify the signal, which is the same as its time to amplify the signal to a specific gain. Settling time for these three types of power amplifiers have also been tested and presented for the performance of these power amplifiers.

Abstract: Synthesis and characterization of CuInS₂ quantum dots (QDs) and CuInS₂ QDs/TiO₂ with varied temperature reaction (200; 215°C) and TiO₂ precursor concentrations was conducted using wet chemical method. The as-synthesized CIS with higher reaction temperature exhibited deep-red emissions and enhanced the photoluminescence (PL) intensity, indicating the reduction of surface defects. With the addition of TiO₂ precursor, particle size decreased, bandgap energy increased, and the absorption edge shifted to the blue region. The UV-Vis absorption shifting expands the light-absorbing region. CIS hybridized with 150 μl TiO₂ precursor (CIS-TO 150) has particle size 2.15 nm with tetragonal chalcopyrite crystal structure and bandgap energy 2.72 eV. This property gives a great potential for wide range of application via photocatalytic mechanism under visible light.

Abstract: This research work designs a power amplifier with the use of Silicon-based Double-Gate (DG) MOSFET. It is a novel device used to amplify the input signal of an audio signal, etc. This research paper provides information on the problem identification in the existing models and its design objectives with its design constraints. It also reduces crossover distortion due to DG MOSFET instead of BJTs and MOSFETs in the class-B power amplifier. This is a low-power device for the mA range using SiO₂ as a dielectric material.

Abstract: This present work is about simulating and analysing a Vertical Cavity Surface Emitting Laser (VCSEL) structure used in optical fibre communication systems. In this paper a VCSEL structure made of seven Quantum Wells of Indium Gallium Arsenide Phosphide (InGaAsP) emitting at 1550 nm is simulated. The device is analysed looking at the following characteristics: Direct current current and voltage (IV) characteristics, light power against electrical bias, optical gain against electrical bias, light distribution over the structure, output power and threshold current. Specification of material characteristics, ordinary physical models settings, initial VCSEL biasing, mesh declarations, declaration of laser physical models, their optical and electrical parameters were defined using Atlas syntax. Mirror ratings and quantum wells are the two main parameters that were studied and analysed to come up with structure trends. By determining important device parameters such as proper selection of the emission wavelength and choice of material; a VCSEL with an output power of 9.5 mW was simulated and compared with other structures.

Abstract: The non-linear components has been emphasized for its multiple applications in rewritable recording and data storage devices. Chalcogenide glasses materials are promising due to their high refractive index. In this paper, alloys for Ge₃₀Te _70-xSb_x glasses semiconductor (where x =0.0, 5, 10, 15 and 20) will be fabricated by melt quenching method. The effect of partial substitution on DC electric power parameters, and its knowledge of electrical conduction mechanisms, were investigated to determine the effect of Antimony on the density of extended states, local states, and in Fermi energy states. The electrical measurements revealed the existence of three conduction mechanisms depend on the temperature: at high temperature the conduction will be in the extended state. The local states are responsible at medium temperature, and at low temperature it will related to the Fermi level. The effect of partial substitution had produced change in all electrical conductivity parameters including the (extended, localized, and Fermi) density of states, the activation energy, tail width (ΔE), hoping transition distance (R), and interatomic distances a.

Abstract: This study investigated and calculated the fill factor and efficiency of N719 and D149 organic dyes in titanium dioxide (TiO₂) solar cell systems using a current equation that we derived using a quantum transition-state theory (TST). The theory of charge transfer reactions was used to investigate the electronic current to enhance both the fill factor and efficiency of both N719/ and D149/TiO₂ solar cell systems. The current calculated for Di-terabtylammoniumcis-bis (isthiocyanato) bis (2,2-bipyridyl-4,4dicarboxylato) ruthenicyanatoum (II)(N719) and 5-[[4-[4-(2,2-Diphenylethenyl) phenyl]-1,2,3-3a,4,8b-hexahydrocyclopent [b] indol-7-yl] methylene]-2-(3-ethyl-4-oxo-2-thioxo-5-thiazolidinylidene)-4-oxo-3-thiazolidineacetic acid indicated that the molecules of D149, an indoline-based dye, have to be in contact with the semiconductor due to the quantum donor-acceptor scenario model. The efficiency of N719/and D149/TiO₂ solar cells were significantly affected due to transition energy, which is caused by the mechanisms of the charge transfer process. Solvents; such as trifluoroethanol (C₂H₃F₃O), propanol (C3H8O), ethanol (C₂H₅OH), and acetonitrile (C2H3N); were used to determine the current, fill factor, and efficiency. Coefficients of charge transfer; such as transition energy, barrier, driving force energy, current, power-conversion efficiency, fill factor (FF), and efficiency; were evaluated theoretically. The current of the N719/ system with acetonitrile and ethanol solvents was higher than current of the N719/ system with trifluoroethanol and propanol solvents. While the current of the D149/ system with trifluoroethanol and propanol solvents was higher than current of the D149/ system with acetonitrile and ethanol solvents. The current and transition energy efficiencies of both systems varied. devices were found to have the best power conversion efficiency and low transition energies while the power conversion efficiency was large for devices with sizeable current density and activity with lower transition energies. Keywords: Fill Factor, Efficiency, Molecule/Semiconductor, Solar Cells.

Abstract: The evolution of semiconductor from the conventional type to organic semiconductor has not convincingly shown that it is eco-friendly both in the short and long term. This research presents the green solution bio-semiconductor that was synthesized from zinc coated carica papaya. It was observed that carica papaya extracts do not respond significantly to the extracting solution (methanol, ethanol and butanol). The band gap of sample 1 (extract in methanol solution), sample 2 (extract in ethanol solution) and sample 3 (extract in butanol solution) was calculated as 1.98 eV, 2.01eV and 1.93 eV respectively. Further research is therefore recommended for the perfection of the bio-semiconductor.

Abstract: There is the need for the use of biodegradable optical filters. This concept of this work is to solve the problems of electronic waste and enhance spectra filtering in photovoltaic (PV) module. The extract of the Ixora plant was used for this experiment. The extract was doped with 0.05 m of copper. The voltage peak analysis (VPA) was used to analyze the chemical stability of the filter. It was observed that the filter was chemically stable at certain time of the day due to temperature variations on the PV module.

Abstract: This paper describes a study on the remote plasma etching of silicon-based semiconductor wafers after laser separation. Several process parameters having impact on the chip reliability, expressed as changes in die material strength, have been studied and optimized. The results show the potential of fluorine-based plasma processing for cleaning dies and improving die performance and thus have a role as a process enabling advanced packaging technologies.

Abstract: The article covers a solution of a modern electronics problem: improvement of data transmission device speed using the example of fiber-optic communication lines (FOCL). The data processing rate and throughput of transmission channels are determined by capabilities of the optoelectronics and, first of all, by the performance of its hardware components. The article presents all possible ways to improve the performance of FOCL. Design and production of communication devices moves to the nanotechnological level that opens up new possibilities for creation of semiconductors with advanced characteristics. The methods and means chosen for production of the nanostructures are crucial for creation of the new generation hardware components. Graphene is considered as the most promising material for creation of the new generation hardware components for semiconductors. Potential capabilities of the material are not yet fully explored. Isotopic nanoengineering is used as the method for production of the nanostructures with improved characteristics. In particular, we use the neutron transmutation doping technology based on irradiation of a graphite sample with a neutron flux. This method increases content of the ¹³C isotope (natural graphite contains only about 1.1% of this isotope). As a result, the band gap opens bringing the properties of the material closer to the properties of a semiconductor. The closer the width of the graphene band gap to the width of the silicon band gap, the closer the properties of graphene to the properties of semiconducting silicon. Furthermore, all properties of the natural graphite (high throughput and sensitivity to almost the entire optical spectrum) are preserved.