A5070542907- Quantum Dots Synthesis And Properties
- Perovskite Materials and Applications
- Chalcogenide Semiconductor Thin Films
- ZnO doping and properties
- Semiconductor materials and devices
- Advancements in Battery Materials
- Copper-based nanomaterials and applications
- Conducting polymers and applications
- Electronic and Structural Properties of Oxides
- Transition Metal Oxide Nanomaterials
- Semiconductor materials and interfaces
- Gas Sensing Nanomaterials and Sensors
- Advanced Battery Materials and Technologies
- Advanced Thermoelectric Materials and Devices
- Advanced Battery Technologies Research
- Supercapacitor Materials and Fabrication
- TiO2 Photocatalysis and Solar Cells
- 2D Materials and Applications
- GaN-based semiconductor devices and materials
- MXene and MAX Phase Materials
- Thermal properties of materials
- Ga2O3 and related materials
- X-ray Diffraction in Crystallography
- Solid-state spectroscopy and crystallography
- Surface Chemistry and Catalysis
Indian Institute of Technology Bombay
2014-2024
University of Mumbai
2015-2024
Jadavpur University
2023
Bhabha Atomic Research Centre
2023
Applied Materials (United States)
2021
Indian Association for the Cultivation of Science
2020
National Renewable Energy Laboratory
2010
Colorado State University
2010
Weizmann Institute of Science
2002-2008
Missouri University of Science and Technology
2007-2008
Hybrid organic–inorganic semiconducting perovskite photovoltaic cells are usually coupled with organic hole conductors. Here, we report planar, inverse CH3NH3PbI3–xClx-based inorganic Using electrodeposited NiO as conductor, have achieved a power conversion efficiency of 7.3%. The maximum VOC obtained was 935 mV an average value being 785 mV. Preliminary results for similar using CuSCN conductor resulted in devices up to 3.8% efficiency. ability obtain promising and expands the presently...
Pseudohalide thiocyanate anion (SCN–) has been used as a dopant in methylammonium lead tri-iodide (MAPbI3) framework, aiming for its use an absorber layer photovoltaic applications. The substitution of SCN– pseudohalide anion, verified using Fourier transform infrared (FT-IR) spectroscopy, results comprehensive effect on the optical properties original material. Photoluminescence measurements at room temperature reveal significant enhancement emission quantum yield MAPbI3–x(SCN)x compared to...
Molybdenum nitride (MoNx) thin films are deposited by atomic layer deposition (ALD) using molybdenum hexacarbonyl [Mo(CO)6] and ammonia [NH3] at varied temperatures. A relatively narrow ALD temperature window is observed. In situ quartz crystal microbalance (QCM) measurements reveal the self-limiting growth nature of that further verified with ex spectroscopic ellipsometry X-ray reflectivity (XRR) measurements. saturated rate 2 Å/cycle 170 °C obtained. The chemistry studied in Fourier...
Highly reproducible and reversible thermochromic nature of dihydrated methylammonium lead iodide is found. A wide bandgap variation the material (∼2 eV) detected between room temperature 60 °C under ambient condition as a result phase transition caused by moisture absorption desorption. In situ X-ray diffraction Fourier transform infrared spectroscopy studies are performed to understand mechanistic behavior during transition. This property further explored absorber in mesostructured solar...
The recent evolution of solution-processed hybrid organic–inorganic perovskite-based photovoltaic devices opens up the commercial avenue for high-throughput roll-to-roll manufacturing technology. To circumvent thermal limitations that hinder use metal oxide charge transport layers on plastic flexible substrates in such technologies, we employed a relatively low-power nitrogen plasma treatment to achieve compact SnO2 thin-film electrodes at near room temperature. perovskite thus fabricated...
Finding stable analogues of three-dimensional (3D) lead halide perovskites has motivated the exploration an ever-expanding repertoire two-dimensional (2D) counterparts. However, bandgap and exciton binding energy in these 2D systems are generally considerably higher than those 3D due to size dielectric confinement. Such quantum confinements most prominently manifested extreme realization (A)mPbI4 (m = 1 or 2) series compounds with a single inorganic layer repeat unit. Here, we explore new...
In2S3 atomic layer deposition (ALD) with indium acetylacetonate (In(acac)3) and H2S was studied quartz crystal microbalance (QCM), X-ray reflectivity (XRR), Fourier transform infrared (FTIR) spectroscopy techniques. Subsequent ALD on TiO2 nanotube arrays defined a model semiconductor sensitized solar cell. For initial Al2O3 surfaces, the displayed nucleation period of ∼60−70 cycles followed by linear growth region. These results were obtained under conditions that not completely...
Recent studies have shown that thermoelectric materials exhibit a high figure-of-merit if it consists of hierarchically organized microstructures significantly lower the lattice thermal conductivity without any appreciable change in power factor. Here, we report new class (AgCrSe2)0.5(CuCrSe2)0.5 nano-composites synthesized via vacuum hot pressing mixture constituents, which naturally phonon scattering centers multiscale hierarchical fashion, i.e. atomic scale disorder, nanoscale amorphous...
Perovskite-based solar cells have attracted much recent research interest with efficiency approaching 20%. While various combinations of material parameters and processing conditions are attempted for improved performance, there is still a lack understanding in terms the basic device physics functional that control efficiency. Here we show perovskite-based two universal features: an ideality factor close to space-charge-limited current regime. Through detailed numerical modeling, identify...
Frequency domain techniques are useful tools to characterize processes occurring on different time scales in solar cells and fuel devices. Intensity-modulated photocurrent spectroscopy (IMPS) is one such technique that links the electrical optical responses of device. In this review, a summary fundamental application IMPS semiconductor photoelectrodes nanostructured presented, with final goal understanding response perovskite cell (PSC) shed light its complex physical mechanisms operation....
Despite having long excited carrier lifetimes and high mobilities in hybrid halide perovskite materials, conventional (n-i-p) devices exhibit significant interfacial nonradiative recombination losses that are little understood but limit the radiative efficiency overall open-circuit potential. In this Letter, we reveal process of spiro-OMeTAD coating on gives rise to buried defect states, which detrimental devices' operational stability. We subsequently report a method passivate these...
This article demonstrates the atomic layer deposition (ALD) of tungsten nitride using hexacarbonyl [W(CO)6] and ammonia [NH3] its use as a lithium-ion battery anode. In situ quartz crystal microbalance (QCM), ellipsometry X-ray reflectivity (XRR) measurements are carried out to confirm self-limiting behaviour deposition. A saturated growth rate ca. 0.35 Å per ALD cycle is found within narrow temperature window 180-195 °C. Fourier transform infrared (FTIR) vibrational spectroscopy used...
ALD grown WS<sub>2</sub> films are recommended to use as intercalation material in Li-ion battery because of its excellent electrochemical stability.
Atomic layer deposition (ALD) of bismuth sulfide (Bi2S3) is demonstrated by the sequential exposure bismuth(III) bis(2,2,6,6-tetramethylheptane-3,5-dionate) [Bi(thd)3] and hydrogen (H2S) at 200 °C. A saturated growth rate 0.34–0.37 Å/cycle was observed in situ quartz crystal microbalance (QCM) verified ex X-ray reflectivity (XRR) measurements throughout ALD temperature window. As-deposited Bi2S3 films were found to be polycrystalline nature without any preferential orientation. In addition...
Thin silver chloride layers evolve oxygen under UV/vis illumination in aqueous solution appropriate conditions. AgCl deposited on a conducting support photocatalyzes the oxidation of water to O2 presence small excess ions solution. The light sensitivity visible part spectrum is due self-sensitization caused by reduced species. Anodic polarization reoxidizes Considerable improvement has been observed with AgBr sensitized photoanodes. To test its splitting capability, photoanode was combined...
The majority of industrial, automobile processes, electrical appliances emit waste heat in the low-temperature range (<573 K), hence efficient thermoelectric materials operating this are highly needed. Bismuth telluride (Bi2Te3) based alloys conventional material for application. pure Bi2Te3 sample synthesized work exhibits n-type conduction. We demonstrate that by small doping Pb at Bi site a transition transport form n- to p-type is observed. figure-of-merit (ZT) ~0.47 and optimized...
Mitigating photocorrosion in the light absorber material used for photoelectrochemical solar water splitting is a subject of major research. In this work, systematic investigation carried out on suppressing an electrodeposited Cu 2 O photocathode using stable protective layers. The protected with chemical vapor deposited graphene offers significant stability, till 600 s during chopping chronoamperometry. However, presence few microcracks layer cannot offer complete protection, and causes...