A5091557584- Topological Materials and Phenomena
- 2D Materials and Applications
- Ga2O3 and related materials
- GaN-based semiconductor devices and materials
- Chalcogenide Semiconductor Thin Films
- ZnO doping and properties
- Quantum Dots Synthesis And Properties
- Graphene research and applications
- Physics of Superconductivity and Magnetism
- Electronic and Structural Properties of Oxides
- Advanced Thermoelectric Materials and Devices
- Gas Sensing Nanomaterials and Sensors
- Gold and Silver Nanoparticles Synthesis and Applications
- Superconductivity in MgB2 and Alloys
- Advanced Semiconductor Detectors and Materials
- Photocathodes and Microchannel Plates
- Nanowire Synthesis and Applications
- Force Microscopy Techniques and Applications
- Photonic Crystals and Applications
- Advanced Condensed Matter Physics
- Quantum and electron transport phenomena
- Plasmonic and Surface Plasmon Research
- Perovskite Materials and Applications
- Mechanical and Optical Resonators
- Photonic and Optical Devices
Academy of Scientific and Innovative Research
2016-2025
Council of Scientific and Industrial Research
2015-2024
CSIR National Physical Laboratory of India
2013-2023
Material (Belgium)
2014
National Physical Laboratory
2014
Harvard University
2008-2011
Harvard University Press
2009
University of Basel
2002-2008
Trinity College Dublin
2008
We report the fabrication of ultraviolet photodetector on non-polar (11–20), nearly stress free, Gallium Nitride (GaN) film epitaxially grown r-plane (1–102) sapphire substrate. High crystalline leads to formation two faceted triangular islands like structures surface. The fabricated GaN exhibited a high responsivity 340 mA/W at 5 V bias room temperature which is best performance reported for a-GaN/r-sapphire films. A detectivity 1.24 × 109 Jones and noise equivalent power 2.4 10−11 WHz−1/2...
Recently, very exciting optoelectronic properties of Topological insulators (TIs) such as strong light absorption, photocurrent sensitivity to the polarization light, layer thickness and size dependent band gap tuning have been demonstrated experimentally. Strong interaction with TIs has shown theoretically along a proposal for based broad spectral photodetector having potential perform at same level that graphene photodetector. Here we demonstrate focused ion beam (FIB) fabricated nanowires...
The rising demand for optoelectronic devices to be operable in adverse environments necessitates the sensing of ultraviolet (UV) radiation. Here, a self‐driven, highly sensitive, fast responding GaN nanoflower based UV photodetector is reported. By developing unique structures, light absorption increases efficiently and maximum responsivity 10.5 A W −1 achieved at 1 V bias. reported highest among photodetectors on Si substrates commercially available Si‐based photodetectors. Under...
The fabrication of a superior-performance ultraviolet (UV) photodetector utilizing graphene quantum dots (GQDs) as sensitization agent on ZnO-nanorod/GaN-nanotower heterostructure has been realized. GQD displays substantial impact the electrical well optical performance heterojunction UV photodetector. stimulates charge carriers in both ZnO and GaN allows energy band alignment, which is realized by spontaneous time-correlated transient response. fabricated device demonstrates an excellent...
We demonstrate a novel chemical-free water-based technique to synthesize various forms of cuprous oxide nanostructures at room temperature. The self-assemblies these are formed by the anodic oxidation Cu in deionized (DI) water. Direct growth on SiO(2)/Si (100) substrate has been successfully achieved tuning bias voltage and duration. A variety from one-dimensional nanowires different complex two- three-dimensional structures grown this method. show that morphological evolution self-assembly...
The nanoplasmonic impact of chemically synthesized Au nanoparticles (Au NPs) on the performance GaN nanostructure-based ultraviolet (UV) photodetectors is analyzed. devices with uniformly distributed NPs nanostructures (nanoislands and nanoflowers) prominently respond toward UV illumination (325 nm) in both self-powered as well photoconductive modes operation have shown fast stable time-correlated response significant enhancement parameters. A comprehensive analysis device design, laser...
The development of imaging technology and optical communication demands a photodetector with high responsiveness. As demonstrated by microfabrication nanofabrication advancements, recent progress in plasmonic sensor technologies can address this need. However, these photodetectors have low absorption ineffective charge carrier transport efficiency. Sb2Se3 is light-sensitive material coefficient, making it suitable for applications. We developed an efficient, scalable, low-cost near-infrared...
WTe2 is one of the wonder layered materials, displays interesting overlapping electron-hole pairs, opening surface bandgap, anisotropy in its crystal structure and very much sought appealing material for room temperature broadband photodection applications. Here we report photoresponse thin films microchannel devices fabricated on silicon nitride substrates. A clear sharp rise photocurrent observed under illumination visible (532 nm) NIR wavelengths (1064 nm). The phoresponse convincing...
Bias-dependent trapping and de-trapping can be seen in the SnSe device. At low bias, voltage of carriers device; they start to de-trap after 500 mV bias.
Here we report a chemical-free, simple, and novel method in which part from silver-based anode is controllably used straightforward manner to produce silver nanoparticles (Ag NPs) order fabricate controlled assembly of Ag NPs single walled carbon nanotube (SWCNT) hybrid structures. The attachment distribution along SWCNTs have been investigated characterized by field emission scanning electron microscopy (FESEM). We achieved the decoration with different densities changing deposition time,...
Hot electron injection in 2D layered materials, particular graphene or transition metal dichalcogenides, has been the subject of intense research recent years. The coupling plasmonic nanostructures with nanolayers materials enhances optoelectronic properties even beyond bandgap material and depends on tuning nanomaterials used. In contrast to Au/Ag mostly used nanostructures, Pt/Pd are more promising for design future nano‐plasmonic devices due their strong catalytic activities they exhibit...
Due to miniaturization of device dimensions, the next generations photodetector based devices are expected be fabricated from robust nanostructured materials. Hence there is an utmost requirement investigating exotic optoelectronic properties nanodevices new novel materials and testing their performances at harsh conditions. The recent advances on 2D layered indicate exciting progress broad spectral photodetection (BSP) but still a great demand for fabricating ultra-high performance...
Topological insulators (TIs) possess exciting nonlinear optical properties due to presence of metallic surface states with the Dirac fermions and are predicted as a promising material for broadspectral phodotection ranging from UV (ultraviolet) deep IR (infrared) or terahertz range. The recent experimental reports demonstrating mostly carried out on non-flexible substrates there is huge demand fabrication high performing flexible optoelectronic devices using new exotic materials their...
In the field of photodetectors, antimony selenide (Sb2Se3) is one materials exhibiting wideband photo response, characterized by its suitable bandgap and fast response time. However, apart from these fascinating properties, substrate compatibility plays a vital role in defining device's efficiency. The present study investigates varying broadband thermally grown films on various substrates (Al2O3, SiO2, quartz, pyramidal sapphire). devices Au/Sb2Se3/Al2O3, Au/Sb2Se3/quartz, Au/Sb2Se3/SiO2...
The interaction of cationic surfactants with single dsDNA molecules has been studied using force-measuring optical tweezers. For hydrophobic chains length 12 and greater, pulling experiments show characteristic features (e.g. hysteresis between the relaxation curves, force-plateau along force curves), typical a condensed phase (compaction long DNA into micron-sized particle). Depending on chain surfactant, we observe different mechanical behaviours complex (DNA-surfactants), which provide...