Kaushik Mazumdar

Bio: Kaushik Mazumdar is an academic researcher from Indian Institutes of Technology. The author has contributed to research in topic(s): Superlattice & MOSFET. The author has an hindex of 3, co-authored 14 publication(s) receiving 24 citation(s).

Generation of square and triangular wave with independently controllable frequency and amplitude using OTAs only and its application in PWM

Abstract: This paper presents a self-generating square/triangular wave generator using only the CMOS Operational Transconductance Amplifiers (OTAs) and a grounded capacitor. The output frequency and amplitude of the proposed circuit can be independently and electronically adjusted. The proposed circuit validates its advantage by consuming less amount of power, which is about 71.3 µW. The theoretical aspects are authentically showcased using the PSPICE simulation results. The performance of the proposed circuit is also verified through pre layout and post layout simulation results using the 90 nm GPDK CMOS parameters. A prototype of this circuit has been made using commercially available IC CA3080 for experimental verification. Experimentation also gives the similar output as per the theoretical proposition. The designed circuit is also made applicable to perform pulse width modulation (PWM).

Nanocrack formation due to inverse piezoelectric effect in AlGaN/GaN HEMT

Abstract: In AlGaN/GaN HEMTs, electrical degradation occurs due to high-voltage stress operation which can be described by a critical voltage operation by which degradation starts to take place which is irreversible. Our investigation is on how electrical degradation occurs due to physical degradation in the device. In this work using Griffith's Equation and inverse piezo electric effect we have shown how physical degradation affects electrical properties of the device and we have also shown how cracks are generated in AlGaN epitaxial layer of the device.

Analysis of electron transport in AlGaN/GaN superlattice HEMTs for isotopes 14 N and 15 N

Abstract: There has been considerable interest in superlattice structures of large band gap semiconductors like AlGaN/GaN based arrangements due to its measured parameter and favorable material properties, such as high electron mobility and very high thermal conductivity Hence, an understanding of the electron transport in GaN has always been prioritized to improve the GaN semiconductors based devices Here the transport properties of electron in isotopically mixed Ga 14 N 15 N alloy channels have been studied Different ratio of isotopes has been considered and their effect on the alloy scattering phenomenon of specimen is studied

TUNNELING EFFECT IN DOUBLE BARRIER NITRIDE (AlGaN/GaN) HETEROSTRUCTURES AT VERY LOW TEMPERATURE

Abstract: Tunneling effect has been studied in double barrier (AlGaN/GaN) heterostructure and tunneling probability has been found out for electrons to tunnel across the barrier. Tunneling probability changes as the temperature changes. Here tunneling probability has been taken at very low temperature (77K). The potential distribution has been shown in the heterostructure. Tunneling current for double barrier nitride (AlGaN/GaN) heterostructure has been traced and revealed figure of merit at 77K equals about 15.

Mobility of 1-D GaAs Quantum Wire Limited by Polar Optic Phonon Scattering

Abstract: The polar optical phonon (POP) scattering limited mobility in 1-DEG quantum wire of GaAs has been investigated The variation of mobility with well width for 1D GaAs quantum wire has been studied The mobility dependence on the transverse dimension of quantum wire for different values of electron energy has been also been investigated The results obtained at 300K for GaAs wire reveal that the variation is almost linear in nature

Electron transport within the wurtzite and zinc-blende phases of gallium nitride and indium nitride

Abstract: Wide energy gap semiconductors are broadly recognized as promising materials for novel electronic and opto-electronic device applications. As informed device design requires a firm grasp on the material properties of the underlying electronic materials, the electron transport that occurs within the wide energy gap semiconductors has been the focus of considerable study over the years. In an effort to provide some perspective on this rapidly evolving and burgeoning field of research, we review analyzes of the electron transport within some wide energy gap semiconductors of current interest in this paper. In order to narrow the scope of this review, we will primarily focus on the electron transport that occurs within the wurtzite and zinc-blende phases of gallium nitride and indium nitride in this review, these materials being of great current interest to the wide energy gap semiconductor community; indium nitride, while not a wide energy gap semiconductor in of itself, is included as it is often alloyed with other wide energy gap semiconductors, the resultant alloy often being a wide energy gap semiconductor itself. The electron transport that occurs within zinc-blende gallium arsenide will also be considered, albeit primarily for bench-marking purposes. Most of our discussion will focus on results obtained from our ensemble semi-classical three-valley Monte Carlo simulations of the electron transport within these materials, our results conforming with state-of-the-art wide energy gap semiconductor orthodoxy. A brief tutorial on the Monte Carlo electron transport simulation approach, this approach being used to generate the results presented herein, will also be provided. Steady-state and transient electron transport results are presented. The evolution of the field, a survey of the current literature, and some applications for the results presented herein, will also be featured. We conclude our review by presenting some recent developments on the electron transport within these materials. This review is the latest in a series of reviews that have been published on the electron transport processes that occur within the class of wide energy semiconductor materials. The results and references have been updated to include the latest developments in this rapidly evolving field of study.

Perovskite solar cell-hybrid devices: thermoelectrically, electrochemically, and piezoelectrically connected power packs

Abstract: Findings and reports in the field of perovskite solar cells (PSCs) have been phenomenal and embrace diverse perspectives such as technical issues, yielding, marketing, and environmental concerns. Bottlenecks in the structure, manufacturing, and operation of PSCs have been frequently addressed; the use of various means including crystallography and kinetics studies, simulation, material, solution, and surface/interface engineering, as well as their outcomes, have yielded certified efficiency of 23.7%. However, the short lifecycle, large waste-to-harvest ratio, functional failure during bending and in the dark mode, environmental and stability issues, and lack of power storage hinder their commercial viability. As a remedy, PSCs can be teamed up with one or multiple mechanical or thermal energy-harvesting or electrochemical power storage devices that can fully or partially overcome these nonidealities. Here, the means of integrating different devices with PSCs to form hybrid packs are discussed. The factors contributing toward the efficiency and mechanical robustness of PSCs and their hybrid devices upon integration are investigated. As an essential bridging component, carbon electrodes are also considered. Furthermore, due to the pressing standards in the energy sector, hybrid devices with nontoxic lead (Pb)-free perovskites should form ideal power packs. Therefore, with reference to their lattice model, optical characteristics, and resulting photovoltaic (PV) performance, they have also been briefly highlighted.

A novel Schmitt trigger and its application using a single four terminal floating nullor (FTFN)

Abstract: In this research paper, a simple clock wise and counter clock wise Schmitt trigger employing single four terminal floating nullor (FTFN) with two external resistors is presented. The proposed Schmitt trigger avails CMOS based FTFN and it is extended for the application as a square and triangular wave generator, by adding an external capacitor to it. In addition, the proposed waveform generator provides independent tunability of amplitude of square wave by implementing the passive resistors using MOS transistors which make the circuit to be integrated fully. Finally, the verification of the proposed design is verified using PSPICE to justify the theoretical analysis. Also, post layout simulation and the experimental verification using commercially available current feedback operational amplifier named as ICAD844 based implementation for FTFN are included to confirm the reliability of the circuit.

Fully Electronically Tunable and Easily Cascadable Square/Triangular Wave Generator with Duty Cycle Adjustment

Abstract: A novel multiple-output dual-X current conveyor transconductance amplifier with buffer-based square/triangular wave generator is introduced in the paper. The proposed generator provides square wave...

Self generating square/triangular wave and pulse width modulator using a single MO-CCCDTA

Abstract: A self-generating square/triangular wave and pulse width modulator (PWM) using multiple output current controlled current differencing transconductance amplifier (MO-CCCDTA) is presented. To obtain all the three functions simultaneously from the same topology, the MO-CCCDTA is modified a little bit. The characterisation of the modified MO-CCCDTA structure shows that the parasitic resistances at input terminals (n and p) can be varied via bias current. The maximum useful frequency range is found to be 635 MHz, which is higher than the available literature. The waveform generator and PWM circuit use only one MO-CCCDTA, one grounded capacitor and no resistor; hence suitable for IC implementation. The duty cycle of proposed pulse width modulation can be tuned by bias current of MO-CCCDTA over a wide range. The performances of the proposed block and its applications (square/triangular/PWM) are verified by PSPICE simulation using TSMC 0.35 µm technology. The power consumption is about 1.12 mW. To verify experimentally, a prototype of MO-CCCDTA has been made using commercially available ICs (AD844AN and CA3080) on printed circuit board. The simulation and experimental results verify theoretical proposition well. Monte carlo simulation is carried out, which proves satisfactory performance of the proposed circuit against mismatches. The performance of the proposed circuit is also verified through pre-layout and post-layout simulation results. The required chip area is only 22.415 × 14.6 µm2.