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Your search keyword '"Sengupta, Ankita"' showing total 19 results
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19 results on '"Sengupta, Ankita"'

2. Light-activated memristor by Au-nanoparticle embedded HfO$_2$-bilayer/p-Si MOS device

Author

Sengupta, Ankita, Chowdhury, Basudev Nag, Roy, Bodhishatwa, Satpati, Biswarup, Bhunia, Satyaban, and Chattopadhyay, Sanatan

Subjects
Physics - Applied Physics, Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

The current work proposes a novel scheme for developing a light-activated non-filamentary memristor device by fabricating an Au-nanoparticle embedded HfO$_2$-bilayer/p-Si MOS structure. Under illumination, the electrons in such embedded Au-nanoparticles are excited from d-level to quantized s-p level and are swept out on application of an appropriate gate bias, leaving behind the holes without recombination. Such photogenerated holes are confined within the nanoparticles and thus screen the external field to lead to a memristive effect in the device. The phenomenon is experimentally observed in the fabricated Pt/HfO$_2$-(layer-II)/Au-NPs/HfO$_2$-(layer-I)/p-Si devices, where such memristive effect is activated/deactivated by light pulses. The memory window and high-to-low resistance ratio of the device are obtained to be ~1 V and ~10, respectively, which suggest the performance of a standard state-of-the-art memristor. Further, the present device offers a voltage-sweep-endurance up to at least 150 cycles and the memory retention up to ~10,000 s. Such a device concept can be extended for a combination of different nanoparticles with various dimensions and dielectric layers to optimize their memristive effect for achieving CMOS-compatible memory devices with superior reliability.

Published
2023

3. Sputtered HfO2/ZrO2 Induced Interfacial Ferroelectric HZO Layer for Negative Capacitance Applications

Author

Sengupta, Ankita, Nag Chowdhury, Basudev, Roy, Bodhishatwa, Sikdar, Subhrajit, Chattopadhyay, Sanatan, Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Rüdiger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Hirche, Sandra, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Li, Yong, Series Editor, Liang, Qilian, Series Editor, Martín, Ferran, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Möller, Sebastian, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Oneto, Luca, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Speidel, Joachim, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zamboni, Walter, Series Editor, Zhang, Junjie James, Series Editor, Giri, Chandan, editor, Iizuka, Takahiro, editor, Rahaman, Hafizur, editor, and Bhattacharya, Bhargab B., editor

Published
2023
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7. Investigation of Highly Efficient Dual-Band Photodetector Performance of Spin-on-Doping (SOD) Grown p-Type Phosphorus Doped ZnO (P:ZnO)/n-Ga2O3 Heterojunction Device

Author

Mishra, Madhuri, Saha, Rajib, Saha, Archishman, Dalal, Avijit, Sengupta, Ankita, Mondal, Aniruddha, Chattopadhyay, Sanatan, and Chakrabarti, Subhananda

Abstract

We developed a stable and reproducible p-type P:ZnO thin film using a cost-effective solution-derived spin-on-doping (SOD) technique. We created a pure p-n heterojunction by depositing a highly transparent Ga2O3 thin film on P:ZnO for photodetector applications. The films’ surface morphology and thickness were analyzed using AFM and FEGSEM. At the same time, UV-visible (UV–Vis) and PL spectroscopy were employed to investigate their optical properties, including absorption, energy bandgap, and defect-related carrier transitions. The resulting P:ZnO/Ga2O3 heterojunction demonstrated excellent photo-response performance, with a responsivity of 4.76 A/W, detectivity of $10.13\times 10^{{12}}$ Jones, and rapid response speed. The device exhibited sensitivity to UV-C and UV–Vis wavelength regions, showcasing its potential for high-performance, dual-band, and low-power photodetectors.

Published
2024
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13. Impact of deposition temperature on crystalline quality, oxygen vacancy, defect modulations and hetero-interfacial properties of RF sputtered deposited Ga2O3 thin films on Si substrate.

Author

Saha, Rajib, Bhowmick, Sangita, Mishra, Madhuri, Sengupta, Ankita, Chattopadhyay, Sanatan, and Chakrabarti, Subhananda

Subjects
THIN films, RADIOFREQUENCY sputtering, OPTOELECTRONIC devices, IMAGING systems in chemistry, X-ray photoelectron spectroscopy, CHEMICAL properties, ATOMIC force microscopy, RADIO frequency
Abstract

In the current work, thin film (∼55 nm) of n-type Ga2O3 (n-Ga2O3) is deposited on silicon (p-Si) substrate by using radio-frequency (RF) sputtering technique with systematic substrate temperature variations (room temperature to 700 °C). The structural, optical properties and chemical states of elements of the deposited films are observed to depend significantly on the deposition temperatures. The chemical composition and oxidation states, optical properties, defect states and structural quality of the deposited films are investigated in detail by employing x-ray photoelectron spectroscopy, energy dispersive x-ray, spectroscopic ellipsometry, Raman, photoluminescence and atomic force microscopy images. X-ray diffraction result reveals a polycrystalline nature of monoclinic β -phase of Ga2O3 with (403) dominant plane. The work functions are calculated from the ultraviolet photo-electron spectroscopy for all the deposited films and Ga2O3/Si heterojunction properties are investigated by using currentâ€"voltage (I â€" V) and capacitanceâ€"voltage (C â€" V) measurements. Among all the fabricated heterojunctions, 600 °C deposited Ga2O3 film exhibits superior performance in terms of energy bandgap, work function, refractive index, barrier height, rectification ratio and effective carrier concentrations. The current transport mechanism is analysed using the appropriate energy band diagram of Ga2O3 and Si. Therefore, the study suggests that 600 °C deposition temperatures is the optimum temperature for developing a high quality Ga2O3 thin film on Si by using RF sputtering technique and corresponding Ga2O3 thin film/Si heterojunction can be a potential candidate for developing several electronic and optoelectronic devices. [ABSTRACT FROM AUTHOR]

Published
2022
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