Dr. Rudra Sankar Dhar - Academia.edu (original) (raw)

Papers by Dr. Rudra Sankar Dhar

Journal of computational electronics, Feb 19, 2024

Journal of physics, Dec 1, 2020

2022 International Conference on Intelligent Controller and Computing for Smart Power (ICICCSP), Jul 21, 2022

Lecture notes in networks and systems, 2022

Lecture notes in electrical engineering, 2023

Physica Scripta, May 23, 2023

Dental Restorative materials play a very important role in solving the issue of sensitivity in hu... more Dental Restorative materials play a very important role in solving the issue of sensitivity in human teeth. Many such materials, based on their respective optical properties, are considered for various usages viz. cavity treatment, reparation of cracked or broken teeth, detection of plaque formation, etc Another way is to deal with different restorative materials for dentistry application which should be ideal and appropriate. Surface Plasmon Resonance (SPR), being an optical phenomenon, has the capability to analyze the optical properties which may be used for Bio-medical Applications also. Considering the adsorption efficiency (to bio-molecules) of Graphene material can be applied for detecting any plaque formation in the essential components of a human teeth viz. Enamel, Dentin and Cementum. Sensitivity, Figure of Merit (F.O.M.) calculations and the correlation between refractive index of different dental restorative materials and their concentration percentage have been tabulated in this manuscript. SPR curves have been obtained using MATLAB environment and Characteristic Transfer Matrix (CTM). A new theoretical approach to detect the teeth-health with harm free (without X-ray source) technique has been proposed. A new technique is considered to determine the quality (cavity formation and others) of teeth-hygiene using less health-hazard radiation. LASER beam-based SPR phenomenon is projected here to identify the tooth condition, which may be implemented for the application purpose.

Annual Reviews in Control, Dec 31, 2023

Scientific reports, Feb 5, 2024

This research explores a comprehensive examination of gate underlap incorporated strained channel... more This research explores a comprehensive examination of gate underlap incorporated strained channel Cylindrical Gate All Around Nanowire FET having enriched performances above the requirement of the 2 nm technology node of IRDS 2025. The device installs a combination of strain engineering based quantum well barrier system in the channel region with high-k spacers sandwiching the device underlaps and stack high-k gate-oxide. The underlaps are prone to parasitic resistance and various short channel effects (SCEs) hence, are sandwiched by HfO 2 based high-k. This SCE degradations and a strong electric field in the drain-channel region is rendered controlling the leakages. The strain based Nanosystem engineering is incorporated with Type-II heterostructure band alignment inducing quantum well barrier mechanism in the ultra-thin cylindrical channel region creating an electrostatic charge centroid leading to energy band bending and splitting among the twofold and four-fold valleys of the strained Silicon layer. This provides stupendous electron mobility instigating high current density and electron velocity in the channel. Thereby, the device is susceptible to on-current enhancement via ballistic transport of carriers and carrier confinement via succumbing of quantum charge carriers. The device transconductance, I on , I off , I on /I off ratio are measured and the output performance (I D-V DS) characteristics is determined providing emphatic enrichments in contrast to the existing gate all-around FETs as well as the 2 nm technology node data of IRDS 2025. Hence, the strained channel Nanowire FET device developed here is presented here as the device of the future for various digital applications, RF applications and faster switching speed. Today's world is marked by a consistent trend of device structure modernization through material modifications, which leads to ongoing transistor scaling. Short channel effects (SCEs) are caused by device downscaling 1 and the SCE optimization beyond 20 nm technology node is a challenging task. The SCEs obligate a significant impact on electrical properties at the nanoscale, such as mobility deterioration, changes in threshold voltage, and a rise in off-current leakages 2 leading to generation of hot carriers at nano regime. Furthermore, these hot carriers produce trap charges at the MOSFET structure's Si-SiO 2 interface, which significantly boosts SCEs and causes subsequent degradations in device performances. Many solutions are being researched to improve device performance and reduce variability, including the invention of nanowire FET (NW FET) 3 , introduction of high-k gate stack 4 , and substantial channel doping profile 5 , multi-gate structured FETs 6 , and electron mobility augmentation employing strain technology 7. Many of the recent investigations on strain engineering have also revealed mobility amplification techniques by reducing V th 8,9. Strain in short-channel devices mitigates the current degradation due to parasitic resistance and dipping of voltage by increasing the effective carrier velocity in the device channel. Because of these notable improvements in the strained silicon channel, which allow for higher drive currents without gate oxide scaling, the industry has quickly embraced the transport characteristics of the strained silicon technology. Global strain and local strain approaches are classified as producing biaxial and uniaxial strain, respectively 10. Strain application has two major effects in nano FETs that are: (i) shifting of

International Journal for Multiscale Computational Engineering, Dec 31, 2022

Lecture notes in electrical engineering, Dec 31, 2022

2021 International Conference on Advances in Electrical, Computing, Communication and Sustainable Technologies (ICAECT), Feb 19, 2021

Recently nanomaterials based electrochromic device draws considerable scrutinization for its innu... more Recently nanomaterials based electrochromic device draws considerable scrutinization for its innumerous possibilities in optical application such as intelligent window and advanced display. With these applications purpose and to enhance the performance of electrochromic device new nano materials are characterized and developed. The Nano-material Membrane (NMM) device developed here consisting ITO glass as substrate along with WO3, NiO, and Li treated NiO is analysed for optical modulation and density. The optical modulation under coloured and bleached states is analogized with ECDs shows ~5-30% enrichment in transmittance under visible electromagnetic domain. The optical density is also investigated and NMM device indicates that membrane based devices are good substitute for implementation of intelligent window and smart display.

Scientific Reports, Jul 14, 2023

The incubation of strained nano-system in the form of tri-layered structure as nanowire channel i... more The incubation of strained nano-system in the form of tri-layered structure as nanowire channel in the cylindrical-gate-all-around (CGAA) FET at 10 nm gate length is developed for the first time to keep abreast with the proposed 3 nm technology node of IRDS 2022. The system installs Type-II heterostrain alignment in the channel attesting itself as the fastest operating device debasing the SCEs at nano regime. The ultra-thin strained-channel comprises of two cylindrical s-Si wells encompassing s-SiGe barrier in between, which enables improvement of carrier mobility by succumbing of quantum charge carriers in the region. This results in 2D charge centroid creation with cylindrical based circular Nano-system contemplating electrostatic potential difference leading to enriched electric field, current density and transconductance, while the gate-all-around architecture with increased gate controllability lowers leakage current, in the device. The 10 nm strained-channel CGAA astounded havoc ON current enhancements of ~ 20% over 22 nm strained CGAA, 57% over Si CGAA FET and 75% over proposed 3 nm technology node IRDS 2022 are accomplished. Hence, carrier mobility and velocity enriches instituting quasi-ballistic transport through the Nanowire channel, thereby augments in ~ 28% drain current so the 10 nm channel CGAA FET stands as the most suitable and improved device in nano regime. Enhancing electron mobility, on-current, and transconductance by using strain technology in a nanodevice channel improves overall device performance 1 , but optimising short channel effects (SCEs) beyond the 14 nm technology node is a challenge. These SCEs affect power dissipation and provide significant variations to electrical characteristics rasing off-current leakages in nano regime 2. Numerous approaches, including mobility enhanmcent using strain technologgy 3 , high-k dielectrics metal gate 4 , optimal doping profile design 5 , quasiballistic FETs 6 , and Nanowire (NW) FETs 7 , are researched in order to boost transistor performance and lower device variability. According to the literature, global strain and local strain generates biaxial and uniaxial strain, respectively 8 , bringing about designs such as: strain-silicon on relaxed SiGe 9 , dual-layer strained channel (s-Si/s-SiGe) 10 , Strain-silicon on insulator (SSOI) 11 , and Hetero-structure on insulator (HOI) 12. In order to bridge the energy band gap for improved electron mobility, silicon is subjected to increased strain, which lowers the threshold voltage (V th) 10. It is well-known that the strain strategies have no long-term reliability impact and barely affect the gate oxide quality 13. The application of strain in nanoFETs results in mainly two effects: (i) shift in band energy and (ii) degeneracy splitting of the electronic states within the structure. The conduction band edge in the fourfold valley is higher in energy than the twofold valley due to strained channel 1 , instigating energy band splitting and increasing occupancy of electrons in the twofold valleys. This condition results into forming a twofold degenerate energy band, which in turn congregates in enhanced electron mobility, suppressing the intervalley transition of electrons from lower valley to upper valley reducing the phonon scattering in the ultrathin channel. In order to develop new hetero-structure devices, the concept of strain technology plays a crucial part in current FET technology, because it increases drain current without requiring any additional scaling, which is sufficient

arXiv (Cornell University), Jun 16, 2022

In this paper we describe a system submitted to the INLG 2022 Generation Challenge (GenChal) on Q... more In this paper we describe a system submitted to the INLG 2022 Generation Challenge (GenChal) on Quality Evaluation of the Low-Resource Synthetically Generated Code-Mixed Hinglish Text. We implement a Bi-LSTM-based neural network model to predict the Average rating score and Disagreement score of the synthetic Hinglish dataset. In our models, we used word embeddings for English and Hindi data, and one hot encodings for Hinglish data. We achieved a F1 score of 0.11, and mean squared error of 6.0 in the average rating score prediction task. In the task of Disagreement score prediction, we achieve a F1 score of 0.18, and mean squared error of 5.0.

International Journal of Nanoparticles, 2022

Nanomaterials

Multi-gate field effect transistors (FETs) such as FinFETs are severely affected by short-channel... more Multi-gate field effect transistors (FETs) such as FinFETs are severely affected by short-channel effects (SCEs) below 14 nm technology nodes, with even taller fins incurring fringing capacitances. This leads to performance degradation of the devices, which inhibits further scaling of nanoFETs, deterring the progress of semiconductor industries. Therefore, research has not kept pace with the technological requirements of the International Roadmap for Devices and Systems (IRDS). Thus, the development of newer devices with superior performances in terms of higher ON currents, acceptable leakage currents and improved SCEs is needed to enable the continuance of integrated circuit (IC) technologies. The literature has advocated integration of strained-silicon technology in existing FinFETs, which is highly effective in enhancing ON currents through the strain effect. However, the ON currents can also be amplified by intensifying the number of fins in trigate (TG) FinFETs. Thus, three-fin...

Proceedings of the 14th Annual Meeting of the Forum for Information Retrieval Evaluation

In this paper we describe a system submitted to the CLEF 2019 CheckThat Shared Task. We implement... more In this paper we describe a system submitted to the CLEF 2019 CheckThat Shared Task. We implement an ensemble of a logistic regression model and an LSTM-based neural network model to predict the worthiness of a sentence for fact checking. Our key idea is to train two separate models with high precision and high recall on binary classification task, and then use the binary class probability as a check-worthiness score. Our system achieves a reciprocal rank 0.4419 and mean average precision of 0.1162 for ranking sentences according to their check-worthiness.