Publications by authors named "Badri Vishal"

Article Synopsis
  • Researchers have tackled the challenge of crystal growth alignment in low-dimensional perovskites (LDPs) used for solar cells, specifically those with wide band gaps that hinder charge flow.
  • By adding chlorine to the precursor solution, they induced vertical crystal growth which enhances efficiency.
  • This method led to a significant power conversion efficiency of 9.4% and an open circuit voltage of 1.4V, paving the way for innovative solar applications in buildings and indoor energy solutions.
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Article Synopsis
  • Interface engineering is vital for optimizing perovskite photovoltaics (PVs), focusing on reducing unwanted recombination to improve performance.
  • A novel approach involves creating a photo-ferroelectric perovskite interface by adding an ultrathin ferroelectric layer to enhance charge separation and reduce voltage losses.
  • This innovation has achieved a record open circuit voltage of 1.21 V and a champion efficiency of 24%, demonstrating a promising direction for advanced perovskite PV designs.
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Two-dimensional (2D) and three-dimensional (3D) perovskite heterostructures have played a key role in advancing the performance of perovskite solar cells. However, the migration of cations between 2D and 3D layers results in the disruption of octahedral networks, leading to degradation in performance over time. We hypothesized that perovskitoids, with robust organic-inorganic networks enabled by edge- and face-sharing, could impede ion migration.

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Defects at the top and bottom interfaces of three-dimensional (3D) perovskite photoabsorbers diminish the performance and operational stability of perovskite solar cells owing to charge recombination, ion migration and electric-field inhomogeneities. Here we demonstrate that long alkyl amine ligands can generate near-phase-pure 2D perovskites at the top and bottom 3D perovskite interfaces and effectively resolve these issues. At the rear-contact side, we find that the alkyl amine ligand strengthens the interactions with the substrate through acid-base reactions with the phosphonic acid group from the organic hole-transporting self-assembled monolayer molecule, thus regulating the 2D perovskite formation.

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Article Synopsis
  • Carbazole-based self-assembled monolayers (PACz-SAMs) are being used as effective hole-selective layers in perovskite/silicon tandem solar cells, but the impact of the microstructure of the transparent conductive oxide (TCO) on their performance has been underexplored.
  • The study found that variations in the TCO microstructure, particularly in Sn-doped InO (ITO) substrates with different grain sizes, directly affect the work function (WF) shift and local potential distribution of PACz-SAMs.
  • Amorphous TCOs, like amorphous ITO or those with an amorphous NiO layer, show a consistent surface potential, while microcr
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Thermally evaporated C is a near-ubiquitous electron transport layer in state-of-the-art p-i-n perovskite-based solar cells. As perovskite photovoltaic technologies are moving toward industrialization, batch-to-batch reproducibility of device performances becomes crucial. Here, we show that commercial as-received (99.

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The properties of layered materials are significantly dependent on their lattice orientations. Thus, the growth of graphene nanowalls (GNWs) on Cu through PECVD has been increasingly studied, yet the underlying mechanisms remain unclear. In this study, we examined the GNWs/Cu interface and investigated the evolution of their microstructure using advanced Scanning transmission electron microscopy and Electron Energy Loss Spectroscopy (STEM-EELS).

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Article Synopsis
  • Graphene nanowalls (GNW) are nanosheets of graphitic carbon positioned vertically on substrates and are usually produced through plasma-enhanced chemical vapor deposition (PECVD) techniques using materials like copper or nickel.
  • The research describes a method for creating large, patterned GNW films on copper meshes that avoids expensive cleanroom setups and achieves impressive wall heights of around 300 nm, successfully mimicking the mesh's dimensions.
  • These GNW films exhibit unique properties, such as hydrophobicity, which alters the wetting behavior of surfaces, and can be utilized in lithium-ion battery anodes, showcasing their potential in energy storage applications.*
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Monolithic perovskite/silicon tandem solar cells are of great appeal as they promise high power conversion efficiencies (PCEs) at affordable cost. In state-of-the-art tandems, the perovskite top cell is electrically coupled to a silicon heterojunction bottom cell by means of a self-assembled monolayer (SAM), anchored on a transparent conductive oxide (TCO), which enables efficient charge transfer between the subcells. Yet reproducible, high-performance tandem solar cells require energetically homogeneous SAM coverage, which remains challenging, especially on textured silicon bottom cells.

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The area of oil foams although important industrially has received little academic attention until the last decade. The early work using molecular surfactants for stabilisation was limited and as such it is difficult to obtain general rules of thumb. Recently however, interest has grown in the area partly fuelled by the understanding gained in the general area of colloidal particles at fluid interfaces.

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Video object tracking plays an important role in many computer vision-aided applications. This paper presents a novel multi-path analysis-based video object tracking algorithm. Trajectory of the moving object is refined using a Kalman filter-based prediction method.

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