A5103087449- Quantum Dots Synthesis And Properties
- Copper-based nanomaterials and applications
- Chalcogenide Semiconductor Thin Films
- Block Copolymer Self-Assembly
- Spectroscopy and Quantum Chemical Studies
- Molecular Junctions and Nanostructures
- Material Dynamics and Properties
- Thermal properties of materials
- Lipid Membrane Structure and Behavior
- Gold and Silver Nanoparticles Synthesis and Applications
- Experimental Learning in Engineering
- Graphene research and applications
- nanoparticles nucleation surface interactions
- Photonic Crystals and Applications
- Molecular Spectroscopy and Structure
- Dendrimers and Hyperbranched Polymers
- Distributed and Parallel Computing Systems
- Organic Electronics and Photovoltaics
- Advanced Polymer Synthesis and Characterization
- Iron oxide chemistry and applications
- Gas Sensing Nanomaterials and Sensors
- Conducting polymers and applications
- Thin-Film Transistor Technologies
- Perovskite Materials and Applications
- Supramolecular Self-Assembly in Materials
Indian Statistical Institute
2025
Friedrich-Alexander-Universität Erlangen-Nürnberg
2024
University of Tübingen
2017-2023
Saha Institute of Nuclear Physics
1993-2023
Forschungszentrum Jülich
2019-2021
University of Calcutta
2020
Interface engineering is crucial to achieving stable perovskite photovoltaic devices. A versatile approach developed tailor interface properties via integrating co-assembled monolayers (co-SAMs) at the p-type buried and by capping a two-dimensional (2D) layer n-type upper with vacuum quenching. Optimized co-SAMs promote coverage of hole transport layer, significantly reducing incidence leakage currents. Based on this foundation, we develop damp-heat-stable solar cells precisely tailoring...
We present a comprehensive study on enhancing the thermoelectric (TE) performance of bilayer graphene (BLG) through irradiation with arbitrarily polarized light, focusing AA- and AB-stacked configurations zigzag edges. Utilizing combination tight-binding theory density functional (DFT), we systematically analyze impact light electronic phononic transport properties. Light alters hopping parameters, creating an asymmetric transmission function, which significantly increases Seebeck...
We investigate in situ the structural changes during self-assembly of PbS nanocrystals from colloidal solution into superlattices, solvent evaporation, and ligand exchange at acetonitrile/air interface by grazing incidence small-angle X-ray scattering (GISAXS). simulate fit diffraction peaks under distorted wave Born approximation (DWBA) to determine lattice parameters. observe a continuous isotropic contraction superlattice two different assembly steps, preserving body-centered cubic with...
We simultaneously surface-functionalize PbS nanocrystals with Cu 4,4',4'',4'''-tetraaminophthalocyanine and assemble this hybrid material into macroscopic monolayers. Electron microscopy X-ray scattering reveal a granular mesocrystalline structure strong coherence between the atomic lattice superlattice of within each domain. Terahertz spectroscopy field-effect transistor measurements indicate efficient coupling holes throughout thin film, in conjunction pronounced photoresponse. demonstrate...
We report here the results of a study to understand formation mechanism single crystals transition metal chalcogenide, CuS, at water–toluene interface through an interfacial reaction. Systematic measurements carried out using synchrotron x-ray scattering, electron microscopy, atomic force microscopy and calorimetric techniques clearly show that nano-crystallites CuS form within few minutes as reagents are brought from organic (upper) aqueous (lower) layers interface, then crystallization...
The grazing incidence x-ray scattering results presented here show that the self-assembly process of HgSe nanocrystals formed at a liquid-liquid interface is quite different along in-plane direction and across interface. In situ reflectivity ex microscopy measurements suggest quantized out-of-plane growth for nanoparticles size about [Formula: see text] nm initially. Grazing small-angle films transferred from water-toluene various stages reaction these first form random clusters with an...
Macroscopic superlattices of tin-doped indium oxide (ITO) nanocrystals (NCs) are prepared by self-assembly at the air/liquid interface followed simultaneous ligand exchange with organic semiconductor copper 4,4',4″,4‴-tetraaminophthalocyanine (Cu4APc). By using X-ray photoelectron spectroscopy (XPS), grazing-incidence small-angle scattering (GISAXS), and ultraviolet-visible-near-infrared (UV-vis-NIR) spectroscopy, we demonstrate that molecules largely replace native surfactant from ITO NC...
We report the formation of conductive mesocrystalline superstructures cubic PbS nanocrystals (NCs) through directional cross-linking with organic semiconductors at liquid/air interface monitored simultaneously by in situ grazing incidence small angle X-ray scattering and diffraction. determine superlattice type, its symmetry parameters, atomic orientation NCs from time-resolved patterns. The contraction follows an exponential decay during ligand exchange, preserving always two-dimensional...
Self assembled nanofibers derived from donor-acceptor (D-A) pair of dodecyl methyl viologen (DMV) and potassium salt coronene tetracarboxylate (CS) is an excellent material for the development organic electronic devices particularly ultrafast response to relative humidity (RH). Here we have presented results in-situ grazing incidence small angle x-ray scattering (GISAXS) measurements understand aridity dependent self reorganization nanofibers. The instantaneous changes in organization was...
Abstract Macroscopic superlattices of tin‐doped indium oxide (ITO) nanocrystals (NCs) are prepared by self‐assembly at the air/liquid interface followed simultaneous ligand exchange with organic semiconductors M‐4,4′,4″,4″′‐tetraaminophthalocyanine (M4APc, M = Cu, Co, Fe, Ni, Zn). Transport measurements, focusing on effect metal center ligand, reveal a ligand‐dependent increase in electrical conductance six to nine orders magnitude, suggesting that M4APc provides efficient electronic...
We report on the effect of ligand exchange Cu2SeyS1–y and Cu2Se nanocrystals (NCs) with organic π-system cobalt β-tetraaminophthalocyanine (CoTAPc) analyze changes in structural, optical, electric properties thin films these hybrid materials. A strong interaction surface NCs is revealed by UV/vis absorption Raman spectroscopy. Grazing-incidence small-angle X-ray scattering studies show a significant contraction interparticle distance upon exchange. For copper-deficient Cu2–xSe, this has...
Anthradithiophene (ADT) and its functionalized derivatives have proven to be attractive for high-performance electronic devices based on small-molecule organic semiconductors. In this manuscript we investigate the structural optical properties of thin films difluoro-anthradithiophene (diF-ADT), an ADT derivative, grown by molecular beam deposition (OMBD). By grazing incidence X-ray diffraction reciprocal space maps, show that diF-ADT crystallizes in a film structure similar single crystal...
PbS nanocrystals are surface-functionalized with the organic semiconductor 5,5″-dithiol-[2,2':5,2″-terthiophene] and assembled to afford hybrid nanostructured thin films a large structural coherence an electron mobility of 0.2 cm2/(V s). Electrochemistry, optical spectroscopy, quantum mechanical calculations applied elucidate electronic structure at inorganic/organic interface, it is established that injection into molecule alters its (electronic) structure, which greatly facilitates...
We study the structural coherence of a self-assembled overlayer PbS nanocrystal (NC) superlattice onto an underlying NC monolayer, which acts as template. explore effect templating layer on structure asemblies by varying interfacial strain and determine impact new ligands their structure. The overlayers templates are analyzed grazing-incidence X-ray scattering microscopy. find that differences in lattice parameters 7.7% between two layers tolerated terms "soft epitaxial" assembly into...
We study temperature-dependent charge transport in two-dimensional assemblies of copper sulfide nanodiscs the covellite crystal phase (Cu1.1S). To enhance interparticle coupling, we cross-link nanocrystals with organic π-system Cu-4,4′,4″,4‴-tetraaminophthalocyanine and observe an increase conductivity by 6 orders magnitude. The electrical properties monolayers this hybrid ensemble are consistent a semiconductor exhibit two abrupt changes at discrete temperatures (120 210 K), which may be...
Time-averaged and energy-resolved neutron X-ray scattering reveal the structure of ligand shell, temperature-dependent diffusion phonon spectrum PbS nanocrystals functionalized with oleic acid in solution.
Grazing incidence X-ray diffraction (GIXD) studies of monolayers biomolecules at an air–water interface give quantitative information in-plane packing, coherence length crystalline domains, etc. Rheo-GIXD measurements can reveal changes in the nanocrystalline domains a monolayer under shear. Here, we report GIXD alamethicin peptide, DPPC lipid, and their mixtures steady shear stress. The mixed show flow jamming transition. On other hand, pure 1,2-dipalmitoyl-sn-glycero-3-phosphocholine...
Unraveling the two-dimensional (2D) structural ordering of colloidal particles assembled at a flat surface is essential for understanding and optimizing their physical properties. So far, grazing-incidence small-angle X-ray scattering (GISAXS) has been widely used to determine crystallographic information on 2D self-assembled structures nanosize objects. However, solving structure lattices consisting micrometer (μm)-sized objects still remains challenge using methods. Here, model SCALMS...
Formamidinium (FA)-based perovskites exhibit significant potential for highly efficient photovoltaics due to their promising optoelectronic properties and optimal bandgap. However, the undesired inactive phase arises from multiple crystal nucleation pathways formed by various intermediate phases during film formation process, persistently accompanying it. FA-based frequently struggle form uniform, crystalline films. This challenge complicates development of reliable reproducible...