Department of Electrical Engineering

&ldquo;IIT Jodhpur is committed to impart quality education to facilitate the creation of qualified, competent and responsible human resources to meet the emerging technological challenges of the world. It is working towards creating an equitable learning platform that is positive, accessible and effective in the face of the modern societal and scientific advancements.

Flexibility in curriculum, in all its academic programs, encompassing elements of teaching, research, creativity, innovation and entrepreneurship is the most unique feature of IIT Jodhpur. The Department of Science and Technology (DST), under the National Mission on Cyber Physical Systems, has identified IIT Jodhpur as a Technology &amp; Innovation Hub in the area of Augmented Reality and Virtual Reality. The institute has also been nominated as the coordinator for the Jodhpur City and Knowledge Cluster by the Office of Principal Scientific Adviser, Government of India.

The sprawling 852-acre IIT Jodhpur campus is a majestic tribute to the deep-rooted diverse cultural heritage of the region. The campus is an architectural masterpiece, which is slated to become an international exemplar of sustainability with net-zero energy, and advanced water and waste management strategies.&rdquo;

IIT Jodhpur

This chapter discusses the parameter extraction procedure of the BSIM-IMG model. Every model has its own flow and it is crucial to carefully understand that for parameter extraction. We consider several variables like temperature, geometry, biases, etc. to give a coherent picture of the parameter extraction method. © 2019 Elsevier Ltd. All rights reserved.

Industry Standard FDSOI Compact Model BSIM-IMG for IC Design

Parameter extraction with BSIM-IMG compact model

In this paper, analysis and design of a three-phase-isolated Cuk-based power factor correction (PFC) converter have been proposed. The proposed converter is operated in discontinuous output inductor current mode to achieve PFC at ac input. This avoids the inner current control loop which further eliminates the sensing of current. This makes the system more reliable and robust. The converter requires only one simple voltage control loop for output voltage regulation, and all the power switches are driven by the same gate signal which simplifies the gate driver circuit. The detailed operation of the converter and design calculations are presented. And also a small-signal model of the converter by using current injected equivalent circuit approach is presented to aid the controller design. The experimental results from a 2-kW laboratory prototype with 208-V line-to-line input voltage, 400-V output voltage are presented to confirm the operation of the proposed converter. An input power factor of 0.999, an input current total harmonic distortion of as low as 4.06%, and a high conversion efficiency of 95.1% are achieved from laboratory prototype. © 1986-2012 IEEE.

World University root node

IEEE Transactions on Power Electronics

Three-Phase Single-Stage-Isolated Cuk-Based PFC Converter

The switched boost inverters are single stage topologies that boost dc voltage and convert it to required ac voltage. It requires lesser number of components and is more efficient compared to conventional two stage dc-dc-ac methods. The dc-ac conversion results in second order harmonic currents (SHCs) to be reflected at the source end. It causes various problems such as heating or failure of sources, oscillations in maximum power point tracking. The active or passive filters for SHCs may increase component count as well as increase overall cost of the system. In this paper, a sliding mode control based voltage and current control method method is proposed so as to reduce the SHCs in Switched Boost Inverter (SBI). Also, the transients during dc or ac load variations are kept within allowed range. This results in excellent voltage regulation during load changes. The proposed controller is validated through simulation for different types of load and upto 50 % load variations. © 2019 IEEE.

2019 IEEE 4th International Future Energy Electronics Conference, IFEEC 2019

Second Order Ripple Reduction in Switched Boost Inverter for Standalone Nanogrid Applications

In part I of this paper, we developed physical insights into the role and impact of acceptor and donor traps - resulting from C-doping in GaN buffer - on avalanche breakdown in AlGaN/GaN HEMT devices. It was found that the donor traps are mandatory to explain the breakdown voltage improvement. In this paper, silicon doping is proposed and explored as an alternative to independently engineer donor trap concentration and profile. Keeping in mind the acceptor and donor trap relative concentration requirement for achieving higher breakdown buffer, as depicted in part I of this paper, silicon carbon codoping of GaN buffer is proposed and explored in this paper. The proposed improvement in breakdown voltage is supported by physical insight into the avalanche phenomena and role of acceptor/donor traps. GaN buffer design parameters and their impact on breakdown voltage as well as leakage current are presented. Finally, a modified Si-doping profile in the GaN buffer is proposed to lower the C-doping concentration near GaN channel to mitigate the adverse effects of acceptor traps in GaN buffer. © 1963-2012 IEEE.

IEEE Transactions on Electron Devices

Part II: Proposals to Independently Engineer Donor and Acceptor Trap Concentrations in GaN Buffer for Ultrahigh Breakdown AlGaN/GaN HEMTs

Effect of UV irradiation (λPeak = 365 nm) on the electrical performance of the OFETs with CuPc as active layer is demonstrated. The devices have shown stable electrical performance under dark with avg. and max. field effect mobility of ( 1.0 ± 0.3 ) × 10 -2 and 1.4 × 10-2 cm2, V-1, s-1 respectively. Under UV illumination there found a shift in threshold voltage and change in ON current along with fast response and recovery time of 0.4 s and 2 s respectively with periodic UV ON-OFF pulses. © 2019 IEEE.

2019 Electron Devices Technology and Manufacturing Conference, EDTM 2019

Copper (II) Phthalocyanine based Organic Field-Effect Transistors for UV Photo-detection

Due to increase in number of wireless devices for the development of smarter spaces such as offices, homes etc., Wi-Fi devices are available as off-the-shelf sensing devices. Researchers are looking for various sensing applications which can make reuse of already installed devices to make the human life easy. Wireless human sensing (WHS) has evolved as a field of study of interaction between the human body and on-going wireless communication to extract various human activities, such as sleep, without attaching any sensor to the body. Sleep is an important part of human life and a quality sleep is essential for healthy being. Due to various sleep disorders and physiological conditions quality sleep is obstructed. It is essential to monitor the sleep to estimate quality of the sleep so the remedial measures can be taken thereof. The movements viz. of limbs turns and rollovers made by the subject on the bed during the sleep can be observed with the proposed method of sleep monitoring and a corresponding movement score is created. This is for the first time when the sleep quality is being estimated on the basis of this score by using WHS. We present here optimistic prelim results of the sleep quality estimation based on rollovers through an Artificial Intelligence enabled Wi-Fi network. © 2019 IEEE.

International Symposium on Advanced Networks and Telecommunication Systems, ANTS

AI-enabled Wi-Fi Network to Estimate Human Sleep Quality based on Intensity of Movements

Here, we propose the construction of a sliding mode controller (SMC) for the fractional order descriptor (FOD) systems. This controller design mainly aims to stabilize the FOD system even in presence of matched disturbances by rejecting the disturbance. The controller is designed using an integral sliding mode (ISM) technique. Here, the control law is framed in such a way that it is at least continuous, by which it helps in eliminating the harmful chattering effects of the actuator and also meets the admissibility requirement related to control for the FOD systems. © 2019 EUCA.

2019 18th European Control Conference, ECC 2019

Integral sliding mode control for fractional order descriptor systems

We report a MoS2/GaN heterojunction-based gas sensor by depositing MoS2 over a GaN substrate via a highly controllable and scalable sputtering technique coupled with a post sulfurization process in a sulfur-rich environment. The microscopic and spectroscopic measurements expose the presence of highly crystalline and homogenous few atomic layer MoS2 on top of molecular beam epitaxially grown GaN film. Upon hydrogen exposure, the molecular adsorption tuned the barrier height at the MoS2/GaN interface under the reverse biased condition, thus resulting in high sensitivity. Our results reveal that temperature strongly affects the sensitivity of the device and it increases from 21% to 157% for 1% hydrogen with an increase in temperature (25-150 °C). For a deeper understanding of carrier dynamics at the heterointerface, we visualized the band alignment across the MoS2/GaN heterojunction having valence band and conduction band offset values of 1.75 and 0.28 eV. The sensing mechanism was demonstrated based on an energy band diagram at the MoS2/GaN interface in the presence and absence of hydrogen exposure. The proposed methodology can be readily applied to other combinations of heterostructures for sensing different gas analytes. © 2019 IOP Publishing Ltd.

Nanotechnology

A high-performance hydrogen sensor based on a reverse-biased MoS2/GaN heterojunction

Here, we demonstrate improved NO2 gas sensing properties based on reduced graphene oxide (rGO) decorated V2O5 thin film. Excluding the DC sputtering grown V2O5 thin film, rGO was spread over V2O5 thin film by the drop cast method. The formation of several p-n heterojunctions was greatly affected by the current-voltage relation of the rGO-decorated V2O5 thin film due to the p-type and n-type nature of rGO and V2O5, respectively. Initially with rGO decoration on V2O5 thin film, current decreased in comparison to the pristine V2O5 thin film, whereas depositing rGO film on a glass substrate drastically increased current. Among all sensors, only the rGO-decorated V2O5 sensor revealed a maximum NO2 gas sensing response for 100 ppm at 150 °C, and it achieved an approximately 61% higher response than the V2O5 sensor. The elaborate mechanism for an extremely high sensing response is attributed to the formation and modulation of p-n heterojunctions at the interface of rGO and V2O5. In addition, the presence of active sites like oxygenous functional groups on the rGO surface enhanced the sensing response. On that account, sensors based on rGO-decorated V2O5 thin film are highly suitable for the purpose of NO2 gas sensing. They enable the timely detection of the gas, further protecting the ecosystem from its harmful effects. © 2019 IOP Publishing Ltd.

NO2 gas sensing performance enhancement based on reduced graphene oxide decorated V2O5 thin films

MoO3 is a well-known multifunctional material which can be potentially used in a distinct gas-sensing applications. In this study, we grow the large-scale nanonetwork composed of α-MoO3 nanosheets by using conventional chemical vapor deposition method. The microscopic and spectroscopic characterizations confirm the continuity and crystallinity of the deposited MoO3 film. The dynamic response resistance of the device reveals a high sensitivity of 53% for 1% hydrogen at 180 °C. A detailed gas-sensing mechanism was explained by the depletion-layer modulation process. © 2019 IEEE.