International Journal of Nano and Biomaterials (7 papers in press)
Polysaccharide capped antibacterial silver nanoparticles synthesis using green chemistry
by Joy Sarkar, Gajendra Nath Maity, Somanjana Khatua, Soumitra Mondal, Krishnendu Acharya
Abstract: Advancement of an environment friendly, trustworthy, and speedy route for the production of Ag-NP using natural system is an essential urge in nanotechnology. Biological synthetic techniques are considered as a better alternative over other conventional methods. Silver is a safe inorganic element that are projected as next-gen antimicrobial agent and had been extensively used against several bacterial strains from the ancient times. Here, we document a low-cost green synthesis approach for construction of Ag-NP using fruit extracted polysaccharide of Bruguiera cylindrica, a mangrove plant of Sundarban. During the investigation of GC-MS an adequate amount of glucose was found as major carbohydrate molecule in the extracted polysaccharide. Synthesized Ag-NP were also characteristically described by UV-Vis, DLS, TEM, EDAX, XRD and FTIR. The average diameter of the Ag-NP was 4.5
Keywords: Green synthesis; Bruguiera cylindrica; Polysaccharide; Silver Nanoparticle; Bacterial Growth.
Special Issue on: DevIC 2019 Impact of Nanotechnology on Devices for Integrated Circuits
Extended Nucleic Acid Memory as the Future of Data Storage Technology
by Saptarshi Biswas, Subhrapratim Nath, Jamuna Kanta Sing, Subir Kumar Sarkar
Abstract: The amount of operational data being generated at an exponential rate in various spheres of computing, in turn, has culminated in a pressure on the available silicon memory-constrained by its limited capacity. In recent times, research has been undertaken on DNA computing for memory technology where Nucleic Acid Memory (NAM) was formulated and found to be an efficient alternative for storing a large amount of digital data in the molecular space. This work presents a new encoding scheme which efficiently maps the binary data into a hybrid system of standard as well as non-standard genetic nucleotides to achieve a higher data capacity. Comparative studies have been done with existing encoding schemes, moreover, this work demonstrates the use of unnatural base pairs like Ds-Px and Im-Na which exhibit high stability and high selectivity in a DNA molecule.
Keywords: Memory technology; Nucleic Acid Memory (NAM); Unnatural base pair; Nonstandard nucleotide;.
Role of Stress/Strain Mapping and Random Dopant Fluctuation in Advanced CMOS Process Technology Nodes
by Taraprasanna Dash, Jhansirani Jena, Eleena Mohapatra, Sanghamitra Das, Suprava Dey, Chinmay Maiti
Abstract: Multiple-gate MOSFETs have emerged as potential candidates for the future device generations considering the continuous increase in performance requirements. Introduction of intentional or unintentional stress/strain in CMOS devices is now an integral part of semiconductor manufacturing. Therefore, a great demand to control strain/stress and study their variation in different regions of the MOSFETs has emerged. In this work, biaxial and uniaxial strain techniques are implemented in the channel for both p- and n-type FinFETs necessary for advanced CMOS applications. Stress/strain mapping in strained-Si (n-type) and strained-SiGe (p-type) channels (in trapezoidal tri-gate FinFET devices) are studied through three-dimensional (3D) numerical simulation, with particular focus on the enhancement of drain current. Following the strain/stress profiles simulated, the piezoresistive changes are implemented in the simulator to describe the strain effects on device operation. Further, using an advanced technology CAD (TCAD) simulation framework we have also examined the effects of process-induced variability source such as random discrete dopants (RDD) on the current-voltage characteristics of both types of FinFETs at 7nm Technology Node. We have investigated the impacts of random discrete dopant variability on the characteristics of a 14-nm gate length FinFET transistors (both n and p-type) using a 3D finite element quantum corrected drift-diffusion device simulator. We have also found the fluctuation of critical device parameters such as threshold voltage (VTH), subthreshold slope (SS), on current (ION), and off state current (IOFF), etc., mainly originated from the randomness of distribution of the dopants. Simulation results show the significant fluctuation of the crucial device parameters for both n and p-channel devices at 7nm technology node.
Keywords: Strained-Si; Strained-SiGe; stress/strain mapping; FinFET; Technology computer aided design (TCAD); random discrete dopants (RDD).
Strain Engineering in AlGaN/GaN HEMTs for Performance Enhancement
by Eleena Mohapatra, Rajib Nanda, Sanghamitra Das, Taraprasanna Dash, Jhansirani Jena, Suprava Dey, Chinmay Maiti
Abstract: Power transistors based on gallium nitride enable electronic switches to operate at a much higher speed compared to those based on silicon. The primary focus of the work is to improve the GaN high electron mobility transistor design, to identify the parameters critical to the device breakdown and to develop techniques for high frequency device design with high breakdown voltage using field plate technology. In the first part of this work, using TCAD simulations, we examine the breakdown voltage as a function of field plate geometry. We study the electrostatics of the breakdown fields and the map the strain/stress profile as a function of field plate length and height. In the second part, we show that field plate based GaN HEMT structures can be optimized to have effectively reduced undesirable parasitic capacitances to greatly improve both the high transconductance and current gain cutoff frequency simultaneously. We report a new generation of high performance AlGaN/GaN HEMTs grown on high resistivity SiC substrates. We examine the small signal and large signal device performances against technological parameters such as the gate length, field plate length, and the source-drain contact separation. The device with a gate length of 0.25?m and field plate length of 0.3?m exhibits a maximum dc drain current density of 3.66 A/mm at VGS=3V with an extrinsic transconductance of 233.6 mS/mm and an extrinsic current gain cut-off frequency (ft) of 78.9 GHz.
Keywords: HEMT; AlGaN/GaN; SiC; field plate; drift-diffusion model; hydrodynamic model; TCAD.
All optical Four Bit Twos Complement Generator and Single Bit Comparator using Reflective Semiconductor Optical Amplifier
by Kousik Mukherjee, Kajal Maji, Ashif Raja
Abstract: All Optical Twos complement generator for four bit binary numbers and single bit comparator is proposed and analyzed using reflective semiconductor optical amplifier (RSOA). We use Soliton bits to implement the device and therefore, find application in long distance communication systems. The performance is analyzed in terms of input-output bit patterns, quality factor, extinction ratio, contrast ratio, quality factor, pseudo eye diagram, relative eye opening and amplified spontaneous emission characteristics.
Keywords: All Optical Logic; Two’s complement; Single bit comparator;Semiconductor Optical Amplifier; Soliton Pulse; Quality Factor.
Controlled Hardware Architecture for Fractal Image Compression
by Hasanujjaman ., U. Biswas, M.K. Naskar
Abstract: Fractal Image Compression utilising algorithms have a high demand rnon the memory interface and the processor's arithmetic unit, which in turn fails rnto utilise the full capabilities of a general purpose processor. Since the rnalgorithm is repetitive, the parallelization reduces the time complexity of the rnotherwise expensive coding scheme. The design for FIC is proposed in this rnpaper. It is based on the fact that the algorithm requires only integer arithmetic rnwith repetitive use of the same data set. Making use of multiple functional rnunits, controlled parallelism is introduced in this process. This makes encoding rntime 80 times faster than high-level software implementation. It is 25 times rnfaster than the assembly level implementation on a DSP Processor.
Keywords: FIC; Hardware Architecture; Iterated function systems; Verilog HDL.
Special Issue on: Smart and Nano Materials Applications
Investigation on microstructures and phases of Fe-Ga alloy films deposited by magnetron sputtering
by Jianwu Yan, Ran Zhao, Yingpeng Cha, Qingpeng Li
Abstract: Galfenol (Fe-Ga alloy), as a new magnetostrictive materials, has potentially wide applications in magnetostrictive devices. In this work, Fe-Ga alloy thin films were prepared by slice-style target magnetron sputtering and investigations on microstructures and phases of Fe-Ga alloy films were made to explore the relationship of properties and microstructures. The results show that the component of alloy thin film is related to physical properties of the material itself as well as the area ratio of the patch and target. The phase formed in the films in is disorderly A2 phase with face-centered cubic structure. The films prepared by magnetron sputtering exist in the form of polycrystalline with <110> crystallographic texture perpendicular to the film plane. The structure shape of as-deposited specimens present a maze domain with different contrast and resolution and the magnetic domain decreased with the increase of the Ga content. With the increase of the Ga content, the magnetic domains become more and more irregular. Fe-Ga thin film morphology is related to the growth mode of the film. The microstructures of Fe-Ga alloy films can be controlled by magnetron sputtering technology.
Keywords: Fe-Ga alloy films; magnetron sputtering; magnetic domain; A2 phase.