Ms. Neelu Sharma Profile

Neelu Sharma

at Indian Institute of Technology Bombay

SPIE Involvement:

Author

Publications (11)

Proceedings Article | 3 October 2024 Poster + Paper

Post-growth rapid thermal annealing (RTA): a technological route to achieve high efficient luminescence and reduction of size inhomogeneity in type-II InAs/GaAs(Sb) quantum dots (QDs) heterostructures for opto-electronic applications

Rajib Saha, Sharanya Chakrabarti, Soumya Mahapatra, Neelu Sharma, Subhananda Chakrabarti

Proceedings Volume 13145, 131450F (2024) https://doi.org/10.1117/12.3028520

KEYWORDS: Annealing, Heterojunctions, Gallium arsenide, Optical properties, Indium arsenide, Quantum technologies, Quantum dots, Quantum dot emission, Optoelectronics, Quantum technology applications

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In the current work, impact of ex-situ rapid thermal annealing (RTA) on the optical, structural and crystallographic properties of type-II InAs/GaAs(Sb) QDs heterostructures are investigated in detail. The Stranski–Krastanov (SK) QD heterostructure is grown by using solid-source molecular-beam-epitaxy (MBE) technique with 22% of Sb composition in GaAs(Sb) capping layer. The As-grown (ASG) samples are treated with RTA at temperatures of 750 _°C, 800 _°C, and 850 °C for 30 s under Ar ambient. Temperature dependent and power dependent photoluminescence (TD-PL and PD-PL) measurements are performed to investigate the impact of the emission properties of type-II heterostructures and such annealing induced changes in QD morphology, optical properties and carrier dynamics are remarkably observed due to alloy intermixing in the QD and capping interface region. The 20 K PL peak reveal a strong correlation with the annealing temperature and a strong blueshift (131 nm). The narrow linewidth from 89 nm (ASG) to 32 nm (850 _°C) is found due to an increase in the uniformity of QDs and energy states and their evolution with the RTP temperatures are analysed in detail by using deconvoluted PL peaks. Out-of-plane XRD confirms the slight reduction in hydrostatic strain with the increasing RTA temperature due to the decrease in In-content inside InAs QD. Atomic force microscopy (AFM) of uncapped QDs (surface QDs) reveals the formation of highly uniform and dense single QDs family with increasing the annealing temperature to 850 °C, which shows the good agreement with the low temperature PL result. The impact of postgrowth RTP on the InAs/GaAs(Sb) QDs heterostructures on semi-insulating epi-ready GaAs substrates has been studied extensively, and analysis of the optical properties, morphological evolution, and crystallographic change of the QDs as a function of annealing temperature show good agreement, which gives an insight for development of futuristics solar cells devices.

Proceedings Article | 11 March 2024 Poster + Paper

Performance analysis of lead free organic-inorganic hybrid double perovskites MA2NaBiCl6 based fabricated solar cell device

Neelu Neelu, Nivedita Pandey, Amitabha Nath, Subhananda Chakrabarti

Proceedings Volume 12883, 1288309 (2024) https://doi.org/10.1117/12.3013286

KEYWORDS: Perovskite, Solar cells, Lead, External quantum efficiency, Sustainability, Photovoltaics, Tolerancing, Quantum devices, Materials properties, Quantum data

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Proceedings Article | 30 November 2023 Poster + Paper

Synthesis and characterization study of a novel lead-free hybrid organic-inorganic halide double perovskite (MA)2NaBiCl6 for photonics applications

Neelu Sharma, Nivedita Pandey, Subhananda Chakrabarti

Proceedings Volume 12796, 127960H (2023) https://doi.org/10.1117/12.3004210

KEYWORDS: Perovskite, Lead, Photonics, Spectroscopy, Semiconductors, Scanning electron microscopy, FT-IR spectroscopy, X-ray diffraction, UV-Vis spectroscopy, Transmittance

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Proceedings Article | 30 November 2023 Poster + Paper

Investigation of self-powered photoresponse performance of all inorganic lead-free halide perovskites (CsSnCl3) nanocrystals (NCs) decorated Er:ZnO nanowires/Si heterojunctions

Ajay Kumar, Rajib Saha, Avijit Dalal, Aniruddha Mondal, Neelu Sharma, Subhananda Chakrabarti

Proceedings Volume 12796, 127960G (2023) https://doi.org/10.1117/12.3004180

KEYWORDS: Nanowires, Heterojunctions, Perovskite, Zinc oxide, Silicon, Erbium, Transmission electron microscopy, Photodetectors, Nanocrystals, Light absorption

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In the current study, we report the all-inorganic lead-free halide perovskites-oxide heterojunction based optoelectronic device fabrications on Si substrate by employing cost-effective chemical bath deposition (CBD) and hot-injection techniques. The selective rare-earth doping of erbium (Er) in ZnO nanowires is performed by employing double-step CBD technique on Si platform for developing a superior heterojunction between Er:ZnO and Si. Furthermore, lead-free perovskites NCs of CsSnCl3 are synthesized by using cost-effective hot-injection method and such NCs are decorated over the Er:ZnO nanowires to passivate the surface defect states. The effect of Er-doping and CsSnCl3 incorporation on structural, optical and luminescence properties of nanowire heterojunctions has been successfully investigated by employing XRD, UV-VIS and PL. The crystal structure of Er:ZnO and Er: ZnO-CsSnCl₃ heterojunctions has been analyzed using X-Ray Diffraction (XRD) technique, which confirms the polycrystalline nature of nanowires with the formation of a highly crystalline cubic phase of CsSnCl₃. The optical absorption of Er:ZnO nanowires and CsSnCl₃ NCs are studied by using ultraviolet-visible (UV-VIS) spectroscopy and corresponding energy bandgaps are estimated to be 3.31 eV and 3.24 eV, respectively. The oxygen vacancies and complex defect states are minimized in ZnO nanowires by Er-doping and perovskites NCs addition and such CsSnCl3 decorated Er:ZnO nanowires exhibit enhanced UV luminescence as compared to undoped ZnO. Finally, photoresponse of undoped, Er-doped and CsSnCl₃ incorporated ZnO nanowires/Si heterojunction has been studied by measuring dark and photo-current and photo-current switching at UV-A wavelength region and such heterojunctions shows excellent photoresponse under self-powered mode. Therefore, such perovskites incorporated Er:ZnO nanowires/Si heterojunction can be a potential candidate for fabricating a highly responsive self-powered UV-detector (UV-A).

Proceedings Article | 5 October 2023 Poster + Paper

Investigation of electronic and optical behavior of Ag-based novel double perovskite MA2AgBiCl6 for photovoltaic applications

Neelu Neelu, Nivedita Pandey, Subhananda Chakrabarti

Proceedings Volume 12651, 126510D (2023) https://doi.org/10.1117/12.2677992

KEYWORDS: Perovskite, Scanning electron microscopy, Photovoltaics, FT-IR spectroscopy, Solar cells, Crystals, Materials properties, Photoluminescence, Nanoparticles, Lead

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Proceedings Article | 1 October 2023 Poster + Paper

Impact of Bi doping on the structural and optical properties of the lead-free double perovskites (Cs2SnCl6:Bi3+) for optoelectronic applications

Ajay Kumar, Neelu Sharma, Rajib Saha, Samishta Choudhary, Subhananda Chakrabarti

Proceedings Volume 12659, 1265907 (2023) https://doi.org/10.1117/12.2677960

KEYWORDS: Perovskite, Bismuth, Doping, Luminescence, Tin, Optical properties, Optoelectronics, UV-Vis spectroscopy, Magnesium, Crystals

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Proceedings Article | 10 March 2023 Poster + Paper

Room temperature synthesis and experimental study of novel double perovskite MA2KBiCl6 for photovoltaic application

Neelu Sharma, Nivedita Pandey, Subhananda Chakrabarti

Proceedings Volume 12416, 124160A (2023) https://doi.org/10.1117/12.2648259

KEYWORDS: Perovskite, FT-IR spectroscopy, Lead, Photovoltaics, Nanoparticles, Crystals, Absorption, Bismuth, Absorption spectrum, Scanning electron microscopy

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Proceedings Article | 10 March 2023 Poster + Paper

Room temperature synthesis and experimental study of novel double perovskite MA2KBiCl6 for photovoltaic application

Neelu Sharma, Nivedita Pandey, Subhananda Chakrabarti

Proceedings Volume 12416, 124160A (2023) https://doi.org/10.1117/12.2648259

KEYWORDS: Perovskite, FT-IR spectroscopy, Lead, Photovoltaics, Nanoparticles, Crystals, Absorption, Bismuth, Absorption spectrum, Scanning electron microscopy

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Proceedings Article | 3 October 2022 Poster + Presentation + Paper

A comparative study of Dots-in-a-Double-Well (DDWELL) heterostructures with SK, SML and coupled SK-on-SML as active region

Archishman Saha, Neelu Neelu, Ravindra Kumar, Saranya Reddy Shriram, Subhananda Chakrabarti

Proceedings Volume 12200, 122000C (2022) https://doi.org/10.1117/12.2633251

KEYWORDS: Heterojunctions, Absorption, Quantum dots, Luminescence, Indium arsenide, Sensors, Optoelectronic devices, Crystals, Security technologies, Quantum wells

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