Abdulrahman M. Alamoud

Effects of sulfurization temperature on Cu2ZnSnS4 thin film deposited by single source thermal evaporation method

In this study, the effects of sulfurization temperature on the properties of thermally evaporated Cu2ZnSnS4 (CZTS) thin films were investigated. Molybdenum (Mo) coated soda lime glass (SLG) was used as substrates and stoichiometric CZTS powder (99.95%) was used as the source material. XRD patterns showed that CZTS were formed with preferential orientations of (112) > (220) > (312) for all the investigated films. The intensity of (112) peak is found increasing until a certain temperature indicating that the highest degree of crystallinity is achieved together with secondary phases such as ZnS and SnS. It was confirmed by raman shift at 338 cm−1 from Raman spectroscopy, scanning electron microscopy (SEM) and atomic force microscopy (AFM) results showed a trend for surface roughness as well as morphology. From Hall effect measurement, all deposited films exhibited p-type conductivity. From UV–vis spectroscopy measurement, the optical band gap of all the films are found in the range of potential absorbers for CZTS based thin film solar cells.

FPGA based processing of digital signals using Walsh analysis

A new technique for addition and subtraction of two digital signals is presented and implemented in FPGAs. The proposed technique is based upon the representation of signals as a Walsh series. A spectrum is generated which can be used for analysis and processing of digital signals directly. The results of addition and subtraction of two digital signals, represented as 8-bits signed number with 16 samples are presented.

A Novel Complete Set of Walsh and Inverse Walsh Transforms for Signal Processing

In this paper, we design and implement a novel complete set of Walsh and inverse Walsh transforms for signal processing. The system consists of Walsh Transforms (WT), Digital Signal Processing (DSP) block, inverse Walsh transform (IWT) and a dividing block. The Walsh and inverse Walsh transforms are designed to produce correct results for any input data combinations. A DSP block is designed to perform addition, subtraction and dyadic convolution of Walsh coefficients of two signals. It is found that the proposed Walsh transform structure is superior to many of the reported results when it is implemented on FPGAs.

FPGA Based Analysis and Multiplication of Digital Signals

The importance of processing of digital signals has dramatically increased due to widespread use of digital systems. A new FPGA based technique for processing of two digital signals to generate a new signal as a product of two signals is presented. The technique is based upon the use of orthogonal functions to describe digital signals.

Design and simulation of high-performance lateral bipolar junction transistor on partial buried oxide

ABSTRACT In this work, we propose a new structure of a lateral bipolar junction transistor (LAT-BJT) on partial buried oxide (PBOX). The novelty of the proposed LAT-BJT device is the use of PBOX, covering just base and emitter regions only. A two-dimensional (2D) calibrated simulation study of the proposed LAT-BJT device has shown that the proposed LAT-BJT on PBOX’s performance is unique when the PBOX is just covering base and emitter regions. At this length of PBOX, a sharp enhancement in cut-off frequency (fT) (~10 times higher) is achieved in the proposed LAT-BJT on PBOX in comparison to an LAT-BJT on silicon-on-insulator (SOI). The breakdown voltage of the proposed LAT-BJT on PBOX is double than that of the LAT-BJT on SOI device at this PBOX length. A notable enhancement in current gain (β) is observed in the proposed LAT-BJT on PBOX in comparison to the LAT-BJT on bulk device. To check the performance of the proposed LAT-BJT on PBOX at the circuit level, two inverters have been designed and simulated using the mixed-mode simulations of Atlas simulator. It has been observed that the proposed LAT-BJT on PBOX significantly outperforms the conventional LAT-BJT device in switching performance. A notable improvement of 32% in ON delay and 72.9% in OFF delay is obtained in the proposed LAT-BJT on PBOX device in comparison to the conventional LAT-BJT device.

DC modelling of modified field-effect transistor

An analytical as well as experimental study of JFET-BJT composite unit, referred to as a modified field effect transistor (MFET), is described. Complete analysis of the circuit is presented, and on the basis of this analysis a DC model is proposed. The proposed model showed a very good approximation of the MFET circuit compared to the experimental results.

Charge plasma based partial-ground-plane-MOSFET on selective buried oxide (SELBOX)

In this work, we propose a novel charge plasma based partial ground plane selective buried oxide MOSFET (CP-PGP-SELBOX-MOSFET). In the proposed device source, drain regions and the partial ground planes (PGPs) have been realized by using metals of different work-functions and not by the conventional method of doping. A two dimensional (2D) simulation study has revealed that the magnitude of the short-channel effects (SCEs) have got significantly reduced in the proposed device in comparison to the conventional one. Further, it has been observed that ION/IOFF ratio and subthreshold slope (SS) in the proposed device has been improved significantly in comparison to conventional SELBOX MOSFET. Further, the proposed device is free from doping related issues and can be fabricated at low temperature, as it does not employ the conventional ion implantation for realizing various regions.

A Test Procedure for Investigating Hot Spots in Upgraded Metallurgical Grade Silicon (UMG-Si) Photovoltaic (PV) Modules

A study is presented to investigate the effect of hot spot on Upgraded metallurgical grade silicon (UMG-Si) Photovoltaic and on modules. These modules are designed and fabricated based on cells with different breakdown voltage. The procedure of testing is applied to show the performance of modules for the worst case hot spot condition by using outdoor testing and infrared (IR) camera. This test procedure implements international standards of testing PV modules for hot spots with adaptation to the Kingdom of Saudi Arabia (KSA) environment where necessary. The behavior of modules is compared and studied at different situation to know if this type of material is appropriate for photovoltaic applications in the KSA.

Linearization of a nickel resistance temperature detector and its application in temperature measurement

A theoretical study of a nickel resistance temperature detector (RTD) response linearization incorporating a new scheme, as well as conventional methods, is presented. The proposed scheme exhibits superior performance over conventional methods and offers linear temperature/voltage conversion over a wide dynamic range.