Papers by Dr. Farida Ashraf Ali
Effective degradation of ciprofloxacin and Cr (VI) by surface plasmon resonance induced photocatalyst Ag (0)/BiVO4@SiO2: Performance and mechanism
Inorganic Chemistry Communications, Nov 1, 2022
International Journal of Engineering and Advanced Technology, 2019
This paper provides a complete idea about metal oxide semiconductors ((MOSs) for gas sensing appl... more This paper provides a complete idea about metal oxide semiconductors ((MOSs) for gas sensing application. Metal oxide semiconductor nano-materials are showing much higher strength in many industries, research laboratories and public health and so on with their effective chemical, physical, and electronic properties. The morphology, band gap, porosity, conductivity properties, low cost and high surface area etc. are few of the properties of MOSs that are responsible for the enhancement of sensing properties in various applications. Besides these, now-a-days MOSs are grown in different nanostructures like nano rods, nano flowers, nano sheets, nano-wires etc. using the various growth techniques which are further responsible for their betterment as gas sensors. Therefore, this paper gives a complete idea about the different methods of synthesis of MOSs.
ijcaonline.org
The idea is to convert the heat generated in computer processors to electrical energy and increas... more The idea is to convert the heat generated in computer processors to electrical energy and increase the battery back-up time of the system. A cathode of low work function will closely surround the processor. An anode will be kept closely to cathode. A unit ...
Solid-state gas sensors: sensing mechanisms and materials
Bulletin of Materials Science
Rapid population growth and industrial development are the major reasons for rapid consumption of... more Rapid population growth and industrial development are the major reasons for rapid consumption of our natural resources and increase in pollution. Monitoring of such pollutants and their control is peremptory to avoid any kind of environmental disasters. For this purpose, conventional analytical instruments were used till date, but as per their size, cost, processing and measurement time point of view, they are not the suitable candidates to be used on the forefront. In recent years, with the advancements in the field of material sciences, improvements in the processing and miniaturization techniques, solid-state gas sensors are presenting themselves as an effective alternative for the targeted functionalities in real time. Though they are not capable of giving such precise analysis like analytic instruments, they prove themselves to be the next generation state-of-the-art gas sensors when compared with respect to their cost, compactness, robustness, versatility, etc. The current review article is based on few chemical sensors that measure the concentration of targeted gas using ‘solid state platforms’. Specifically, this paper concentrates on electrochemical-, capacitance- and heterojunction-based solid state sensors explaining their detection principle, mechanism and structure. Over the past few years, the growth and advancement in the area of porous metal oxide (PMO)-based sensors has shown great potential in the field of gas sensing. Owing to the current developments in synthesis methods, numerous porous metal oxides with well-defined surface modification are possible. Therefore, this review article summarizes the different PMO materials employed to enhance the unique properties like increasing surface area, tunable pore sizes, high pore volume, etc. to address the advancements in the field of solid-state gas sensors.
Socially Active Humanoid Robots (SAHRs) in Healthcare
Advances in Medical Technologies and Clinical Practice
Socially active humanoid robots (SAHRs) are designed to communicate and interact with humans in h... more Socially active humanoid robots (SAHRs) are designed to communicate and interact with humans in humancentric environment using speech, movements, gestures, or facial expressions to communicate with their users following some set of social behavior while providing their assistance. Just like humans interact in an adaptive manner with others by changing their speech, tone, and body language intuitively, such type of adaptive behavior can be developed in SAHRs to get a human-like rich interaction capabilities. Therefore, a lot of research work and studies are going on to replicate various behavioral aspects of humans into SAHRs, so that human-robot interaction can be improved further. Besides interacting with humans, humanoid robot should be able to perform the assigned tasks remotely and also in real time with better accuracy. Thus, these social robots designed can be used in a diversified field of applications like education, healthcare, entertainment, communication, constructions, m...
Characterization of strained silicon MOSFET in nano-scale regime using T-CAD
ABSTRACT The challenges to achieve higher mobility, high speed and drive current in transistors w... more ABSTRACT The challenges to achieve higher mobility, high speed and drive current in transistors with traditional scaling, have led to think beyond the conventional Si technology. Strained-Si is one of the promising performance boosters to overcome these entire shortcomings. Here Strained-Si heterojunction p-channel MOSFETs with an abrupt buffer cap of relaxed Si0.7Ge0.3 with 120nm, 100nm and 80nm channel length have been designed and simulated. The simulation provides promising results in terms of transfer characteristics, output characteristics and C-V characteristics. The enhancement in transconductance has been observed upto 1.5 to 2 times higher with reduction of gate length. Furthermore, threshold voltage and subthreshold swing of the above three structures have been extracted. Out of the above three devices, MOSFET with 120-nm channel length provides stable subthrshold swing of 76mv/decade and threshold voltage of 0.42 volt. Further study for the same structure (120-nm) has been done in terms of hole concentration and band effect by replacing abrupt buffer layer as graded SiGe layer. This improvises the band alignment and shows increase in hole concentration by reducing the buried channel effect.
Fabrication of efficient CuS/BiVO4 p-n heterojunctions for sensing and photo-reduction of Cr (VI)
Materials Research Bulletin, 2021
Abstract Applications in sensing and photo reduction of Cr (VI) by pristine BiVO4 are restricted ... more Abstract Applications in sensing and photo reduction of Cr (VI) by pristine BiVO4 are restricted because of the narrow band gap and easy electron-hole recombination. To overcome the issue, CuS is coupled to BiVO4indifferent molar ratios (1:1, 1:2, and 2:1) by hydrothermal synthesis and used in Cr (VI) sensing and photo-reduction. The tetragonal zircon phase of BiVO4 and hexagonal structure of CuS have been confirmed through XRD. Then n-type and p-type behavior of BiVO4 and CuS respectively have been shown from a Mott-Schotky study. The Current–Voltage characteristics of all the samples were found to be linear and ohmic in nature. The conduction and valence band position of BiVO4 (+0.33 eVand +3.08 eV) and CuS (-0.30 eV and +1.81 eV) ensures the development of p-n heterojunction and channelization of the photo-induced charge carriers. This helps in decreasing electron-hole recombination, thereby increasing the sensing efficiency (99%) and photo-reduction (98%) of Cr (VI) at a concentration of 40 ppm.
Journal of Materials Research and Technology, 2020
This research paper demonstrates the synthesis of zero-dimensional (0D) porous cupric oxide (CuO)... more This research paper demonstrates the synthesis of zero-dimensional (0D) porous cupric oxide (CuO) nanoparticles by two different methods i.e. reflux and precipitation, followed by calcinations at different temperatures starting from 350 to 550 • C with an increment of 100 • C. The synthesized materials when calcined at different temperatures not only retain their structure, but also improve the crystalline nature. The maximum mean pore radius is found to be 4.15 nm for the sample calcined at 550 • C, synthesized by reflux technique, which is confirmed through SANS studies. The Cu (II)-O bond has been recorded in the range of 400 to 600 cm −1 and the peak of Cu-O has been observed at 603 cm −1 which is analyzed through FTIR spectra. The optical band gap of CuO is estimated to be 1.8 eV by diffused reflectance spectroscopic studies which indicate that the synthesized CuO nanoparticles are good photo-catalysts for phenol degradation within the wavelength range of visible-light. However, the polydispersity of the calcined materials gradually decreases with increase in temperature. It has been found from the Hall measurement that the synthesized CuO material is p-type in nature and I-V characteristics are linear in nature. As the Ohmic current mechanism is dominant, therefore the synthesized CuO material is an ideal candidate for sensor applications. The electrical conductivity of the CuO nanoparticles enhances when the measurement has been carried out in presence of phenol. It is seen that 450 • C calcined CuO shows highest degradation efficiency of phenol (98%) and phenol sensing.
Microelectronics International, 2019
Purpose The purpose of this paper is to examine the growth and characterization of the two differ... more Purpose The purpose of this paper is to examine the growth and characterization of the two different compound semiconductors, namely, n-zinc oxide (ZnO) and p-gallium antimonide (GaSb). In this paper, fabrication and characterization of n-ZnO/p-GaSb heterojunction diode is analyzed. Design/methodology/approach Thermo vertical direction solidification (TVDS) method was used to synthesize undoped GaSb ingot from high purity Ga (5N) and Sb (4N) host materials. Thermal evaporation technique is used to prepare a film of GaSb on glass substrate from the pre-synthesized bulk material by TVDS method. Undoped ZnO film was grown on GaSb film by sol–gel method by using chemical wet and dry (CWD) technique to fabricate n-ZnO/p-GaSb heterojunction diode. Findings The formation of crystalline structure and surface morphological analysis of both the GaSb bulk and film have been carried out by x-ray diffraction (XRD) analysis and scanning electron microscopy analysis. From the XRD studies, the stru...
Study of 65 nm n-MOSFET Using SILVACO TCAD
Advanced Science Letters, 2016
ABSTRACT Generally, prior to IC fabrication the electrical parameters of transistors are simulate... more ABSTRACT Generally, prior to IC fabrication the electrical parameters of transistors are simulated by simulator software, but many a time to mathematical simulator software are validated by comparing with the experimental findings and then models are corrected accordingly. In this report, the electrical characterization of 65nm NMOS transistor structure is simulated by the ATLAS simulator software and then it is compared with the reported experimental results. The simulated threshold voltage was found to be 0.2V which matches well with the experimental value. Furthermore in the same structure, various short channel effects like punch through, velocity saturation and hot electron generation are studied and reported in this paper.
Interface study of high-k/InAs/n-GaSb MOSCAP structures
2015 International Conference on Electrical, Electronics, Signals, Communication and Optimization (EESCO), 2015
Crystal Growth of Bulk Ga<SUB>1−<I>x</I></SUB>Ni<SUB><I>x</I></SUB>Sb Ternary Alloy and It's Characterization Between 78 K to 300 K
Advanced Science Letters, 2014
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Experiment and Modeling of Schottky Device of Bulk Au/n-GaSb by Vertical Bridgeman Growth
Advanced Science Letters, 2014
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Impact of In<SUB><I>x</I></SUB>Al<SUB><I>y</I></SUB>Ga<SUB>1−<I>x</I>−<I>y</I></SUB>N Layer on GaSb/AlGaAs High Electron Mobility Transistor
Advanced Science Letters, 2014
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2012 IEEE Student Conference on Research and Development (SCOReD), 2012
Optical Character Recognition has been a challenging field in the advent of digital computers. It... more Optical Character Recognition has been a challenging field in the advent of digital computers. It is needed where information is to be readable both to humans and machines. The process of OCR is composed of a set of pre and post processing steps that decide the level of accuracy of recognition. This paper deals with one of the pre-processing steps involved in the OCR process i.e. Skew (Slant) Detection and Correction. The proposed algorithm implemented for skew-detection is termed as the COG (Centre of Gravity) method and for that of skew-correction is Sub-Pixel Shifting method. The algorithm has been kept simple and optimized for efficient skew-detection and correction. The performance analysis of the algorithm after testing has been aptly demonstrated.
Characterisation of bulk GaSb using TCAD
IEEE Technology Students' Symposium, 2011
The III-V compounds have turned out to be promising candidates for high speed electronics and pho... more The III-V compounds have turned out to be promising candidates for high speed electronics and photonic devices. Among I1I-V compounds, gallium antimonide (GaSb) is particularly interesting as a substrate material because its lattice parameter matches solid solutions of various ternary and quaternary III-V compounds whose band gaps cover a wide spectral range. These have stimulated a lot of interest in GaSb for basic research in materials as well as device fabrication. In this paper, investigation is done for the hole transport property of bulk GaSb with intrinsic concentration 1.5x10 15 cm·3• Hole concentration and mobility of bulk GaSb were investigated by simulation method using the device simulation software ATLAS (SILVACO) in the temperature range 77K to 320K in an interval of 5Kand 10K. It also shows that the effective hole mobility is about 461 cm2Ns with the concentration ;:; 1.5 x lOIS cm-3 at room temperature i.e. 300K. It has been found that the effective mobility is affected by ionized impurity scattering; in contrast at higher temperatures (;:; 300K) acoustic, polar optical and non-polar optical scattering processes dominate the mobility. The agreement of simulated data with that of reported experimental data is found to be satisfactory.
Interface Study of Individual and Stacked High-k/P-Si MOSCAPs by CV Technique
Advances in Intelligent Systems and Computing, 2014
Interface trap charge density, threshold voltage, and flat band voltage of aluminum oxide (Al2O3)... more Interface trap charge density, threshold voltage, and flat band voltage of aluminum oxide (Al2O3), hafnium oxide (HfO2), titanium oxide (TiO2), and yttrium oxide (Y2O3) of different oxide thickness have been calculated after high-frequency CV simulation of MOSCAPs at room temperature, where P-type silicon is taken as substrate. The calculated Dit value is less in TiO2 (1.37 × 1010 eV−1 cm−2) than Al2O3 (4.81 × 1010 eV−1 cm−2), HfO2 (1.58 × 1010 eV−1 cm−2), and Y2O3 (2.34 × 1010 eV−1 cm−2) for 5 nm oxide thickness. The threshold and the flat band voltage of all oxide layers are found to be around 0.35 and −0.3 V, respectively, which match well with the experimentally reported values. Furthermore, the CV simulation, threshold, and flat band voltage calculations were done for 10-nm and 15-nm-thick individual oxides (Al2O3, HfO2, TiO2, and Y2O3) and compared. In addition, the interface trap charge densities, threshold voltages, and flat band voltages of stacked HfO2/TiO2 and Al2O3/TiO2, Y2O3/TiO2 are calculated for 2 nm oxide thickness by the same CV technique. It is found that the interface states of stacked HfO2/TiO2 (1.18 × 1010 eV−1 cm−2) are marginally less than stacked Al2O3/TiO2 (1.34 × 1010 eV−1 cm−2) and Y2O3/TiO2 (1.29 × 1010 eV−1 cm−2).
Simulation and Analysis of Interface Properties Due to Variation of Gate Oxide Thickness in Au/Al<SUB>2</SUB>O<SUB>3</SUB>/<I>n</I>-GaSb MOSCAP
Advanced Science Letters, 2014
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Papers by Dr. Farida Ashraf Ali