A5033509256- Quantum Dots Synthesis And Properties
- Chalcogenide Semiconductor Thin Films
- Perovskite Materials and Applications
- 2D Materials and Applications
- Nonlinear Optical Materials Studies
- Semiconductor Quantum Structures and Devices
- Advanced Fiber Laser Technologies
- ZnO doping and properties
- Graphene research and applications
- Copper-based nanomaterials and applications
- Laser-Ablation Synthesis of Nanoparticles
- TiO2 Photocatalysis and Solar Cells
- MXene and MAX Phase Materials
- Graphene and Nanomaterials Applications
- Advanced Photocatalysis Techniques
- Carbon and Quantum Dots Applications
- Solid-state spectroscopy and crystallography
- Photochemistry and Electron Transfer Studies
- Advanced Memory and Neural Computing
- Nanocluster Synthesis and Applications
- Transition Metal Oxide Nanomaterials
- Laser-Matter Interactions and Applications
- Gas Sensing Nanomaterials and Sensors
- Nonlinear Optical Materials Research
- Integrated Circuits and Semiconductor Failure Analysis
Indian Institute of Technology Mandi
2018-2024
Indian Institute of Technology Bombay
2015-2019
Abstract Two-dimensional (2D) tin(II) monosulfide (SnS) with strong structural anisotropy has been proven to be a phosphorene analog. However, difficulty in isolating very thin layer of SnS poses challenges practical utilization. Here, we prepare ultrathin via liquid-phase exfoliation. With transmission electron microscopy, identify the buckled structure 2D SnS. We employ temperature dependent Raman spectroscopy elucidate electron–phonon interactions, which reveals linear phonon shifts. The...
Lead halide perovskites have been widely explored in the field of photovoltaics, light-emitting diodes, and lasers due to their outstanding linear nonlinear optical (NLO) properties. But, presence lead toxicity low chemical stability remain serious concerns. Lead-free double perovskite with excellent properties could be an alternative. However, proper examination NLO such a material is crucial identify utility for future device applications. Herein, we made use femtosecond (fs) Z-scan...
Organometal halide perovskites, an emerging class of direct bandgap semiconductors, are attractive candidates for many optoelectronic device applications. Herein, we have reported the nonlinear optical (NLO) properties layered benzylamine lead(II) bromide perovskite microdisks (MDs) having a lateral dimension few micrometers and average thickness 35 nm, featuring narrow deep blue emission using Z-scan technique. The NLO behavior switches over from saturable absorption to reverse under...
Two-dimensional (2D) transition-metal dichalcogenides (TMDCs) have shown promise for a variety of optoelectronic applications due to wide range optical, electrical, and mechanical properties. Large-area chemical vapor deposition (CVD)-grown TMDC flakes could be useful in such devices. However, the defects present large-area can significantly influence carrier dynamics transport Here, ultrafast monolayer tungsten disulfide (WS2) covering large area substrate was explored using transient...
A quasi 2D Ruddlesden–Popper perovskite, (PEA) 2 Cs 4 Pb 5 Br 16 exhibits superior third-order nonlinear optical properties, which is promising for the development of ultrafast photonic devices.
Utilization of the excess energy photoexcitation that is otherwise lost as thermal effects can improve efficiency next-generation light-harvesting devices. Multiple exciton generation (MEG) in semiconducting materials yields two or more excitons by absorbing a single high-energy photon, which break Shockley-Queisser limit for conversion photovoltaic Recently, monolayer transition metal dichalcogenides (TMDs) have emerged promising because their high absorption coefficient. Here, we report...
In this paper, we report temperature dependent photoluminescence (PL) characteristics of CdSe colloidal QDs with average diameter ~2.8 nm. Temperature dependence strongly confined exciton PL peak position, linewidth and intensity were investigated in 30 K to 300 range. Our studies reveal nearly four times weaker exciton-LO phonon coupling than bulk crystal. Theoretically, it should be vanishingly small due near identical electron hole charge distributions QDs. On the other hand,...
Two-dimensional Ruddlesden–Popper perovskites (TEA) 2 PbBr 4 - and PbI -based resistive switching random-access memory devices exhibit high ON/OFF ratio, excellent data retention, good endurance along with remarkable environmental stability.
Charge carrier trapping by the surface defects of colloidal semiconductor nanocrystal (NC) is a ubiquitous process which limits performance NC-based photovoltaic and photocatalytic devices. Although several empirical approaches led to enhancement device efficiency via passivation trap states, systematic unified description mechanism remains obscure. In this contribution, we present detailed experimental investigation dynamics CdSe NCs with varying concentration traps means time-resolved...
Two-dimensional (2D) inorganic halide nanomaterials are finding tremendous attention owing to ease of synthesis, solution processability, superior electronic, optical, and mechanical properties resulting in versatile applications. All dual phase perovskite composites can have optoelectronic than a single one. In addition phase, doping with various ions may open up new avenues for emerging applications such materials. this work, we report on the synthesis colloidal 2D Mo-doped all mix...
We synthesis different sizes of cadmium selenide quantum dots (CdSe QDs) and their linear nonlinear optical properties. Size-controlled CdSe QDs are characterized by ultraviolet-visible absorption, photoluminescence, transmission electron microscope (TEM), Z-scan techniques. Redshift was observed in the absorption photoluminescence with an increase size QDs. TEM images show 2.2 nm-4.9 nm. Bandgap tuning third-order properties investigated at 532 nm open aperture technique using a picosecond...
We report generation of a broadband supercontinuum (SC) in birefringent crystal upon irradiation by intense, near-infrared, femtosecond laser pulses and investigate its dependence on incident power the initial polarization. choose as our sample $\ensuremath{\alpha}\ensuremath{-}{\mathrm{BaB}}_{2}{\mathrm{O}}_{4}$ ($\ensuremath{\alpha}$-BBO), material which third order is lowest nonvanishing nonlinear optical susceptibility. Three different SC mechanisms are identified under experimental...
Cadmium sulfide (CdS) quantum dots (QDs) doped with different concentrations of manganese (Mn = 0, 1, 3, 5, and 7%) are synthesized by using the thermolysis diselenocarbamato complexes cadmium in trioctylphosphine oxide (TOPO) method. The QDs show size effects optical spectra exhibit band-edge emission. TEM images revealed that spherical within range 3 to 5 nm. nonlinear studies limiting characteristics studied. From open closed aperture data, absorption coefficient (β) refractive indices...
Literature studies on the effects of alkyne functionality in manipulating optical properties donor-π-acceptor-type molecular scaffolds have been scarce compared to those alkene functional group. Here, two structurally isomeric donor-acceptor (D-A) dyes were synthesized study positional effect (triple bond) their optical, electrochemical and charge generation order design efficient for possible application dye sensitized solar cells (DSSCs). These dyes, named CAPC PACC, contain carbazole...
We report temperature-dependent photoluminescence (PL) studies and PL relaxation dynamics for uncoated silver-coated CdS quantum dots (QDs). Room-temperature indicate that the presence of silver coating on QD samples enhances blue luminescence corresponding to band-to-band transitions by a factor ten compared samples. Furthermore, decay time measurements using Time Correlated Single Photon Counting technique demonstrate Förster resonance energy transfer (FRET) between silver-shell CdS-core...