Publications by authors named "Anand B Puthirath"

High-power electronics demand high-speed, highly integrated electrical circuits with excellent heat dissipation. Owing to their ultrawide-bandgap, high thermal stability and chemical inertness, the heterostructure of cubic boron nitride (c-BN) and diamond are predicted as promising power-efficient materials for next-generation electronics. Therefore, extensive efforts are ongoing to develop epitaxial c-BN thin films on diamond with an atomically smooth interface, however with limited success due to the metastable nature of c-BN.

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The engineering of terahertz phonons is challenging due to difficulties in achieving sub-nanometer material precision and in facilitating efficient phonon coupling at terahertz frequencies region. The effective generation, detection, and manipulation of terahertz phonons via the integration of atomically thin layers in van der Waals heterostructures can enable new designs for next-generation optoelectronic quantum devices, offering new avenues for thermal engineering in the terahertz regime. Here, optical pump terahertz probe and terahertz time-domain experiments are used to reveal the behavior of charge carrier transfer in real time at heterostructure interfaces of single-layer graphene and monolayer MoS upon photoexcitation and plausible mechanism has been put forward.

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To overcome the limitations of commercializing lithium-ion batteries (LIBs), a one-step feasible route is reported to prepare a hybrid matrix of molybdenum oxides (MoO, x = 0 and 1) thin film anode. In this direction, the electrical conductivity barriers of MoO dielectric are overcome by reinforcing conductive MoO via the chemical vapor deposition (CVD) route. The intermixed array of nanograins and nanoflakes grown over stainless-steel (SS) foil delivers a maximum gravimetric capacitance of 281 F g and a specific capacity of 348 mAh g at 1 A g.

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The 2D Ruddlesden-Popper (RP) perovskites CsPbICl (Pb-based, = 1) and CsSnICl (Sn-based, = 1) stand out as unique and rare instances of entirely inorganic constituents within the more expansive category of organic/inorganic 2D perovskites. These materials have recently garnered significant attention for their strong UV-light responsiveness, exceptional thermal stability, and theoretically predicted ultrahigh carrier mobility. In this study, we synthesized Pb and Sn-based = 1 2D RP perovskite films covering millimeter-scale areas for the first time, utilizing a one-step chemical vapor deposition (CVD) method under atmospheric conditions.

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Designing efficient and cost-effective materials is pivotal to solving the key scientific and technological challenges at the interface of energy, environment, and sustainability for achieving NetZero. Two-dimensional transition metal dichalcogenides (2D TMDs) represent a unique class of materials that have catered to a myriad of energy conversion and storage (ECS) applications. Their uniqueness arises from their ultra-thin nature, high fractions of atoms residing on surfaces, rich chemical compositions featuring diverse metals and chalcogens, and remarkable tunability across multiple length scales.

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Two-dimensional (2D) layered materials exhibit great potential for high-performance electronics, where knowledge of their thermal and phononic properties is critical toward understanding heat dissipation mechanisms, considered to be a major bottleneck for current generation nanoelectronic, optoelectronic, and quantum-scale devices. In this work, noncontact Raman spectroscopy was used to analyze thermal properties of suspended 2D WSe membranes to access the intrinsic properties. Here, the influence of electron-phonon interactions within the parent crystalline WSe membranes was deciphered through a comparative analysis of substrate-supported WSe, where heat dissipation mechanisms are intimately tied to the underlying substrate.

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Monolayers of MoSwith tunable bandgap and valley positions are highly demanding for their applications in opto-spintronics. Herein, selenium (Se) and vanadium (V) co-doped MoSmonolayers (vanadium doped MoSSe(V-MoSSe)) are developed and showed their variations in the electronic and optical properties with dopant content. Vanadium gets substitutionally (in place of Mo) doped within the MoSlattice while selenium doped in place of sulfur, as shown by a detailed microstructure and spectroscopy analyses.

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Article Synopsis
  • The field of twistronics focuses on the electronic structures of twisted atomically thin layers, but achieving consistent layer alignment and single crystalline quality is a current challenge.
  • A new approach proposes using nanocrystalline two-dimensional (2D) films on three-dimensional (3D) substrates to create properties that depend on the twist between layers.
  • The study demonstrates that growing hexagonal boron nitride (h-BN) thin films on silicon carbide substrates leads to unique optical and thermal properties, making it a promising strategy for practical applications in nanotechnology.
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Enormous enhancement in the viscosity of a liquid near its glass transition is a hallmark of glass transition. Within a class of theoretical frameworks, it is connected to growing many-body static correlations near the transition, often called "amorphous ordering." At the same time, some theories do not invoke the existence of such a static length scale in the problem.

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Diamond surface functionalization has received significant research interest recently. Specifically, H-termination has been widely adopted because it endows the diamond surface with negative electron affinity and the hole carrier is injected in the presence of surface transfer dopants. Exploring different functional groups' attachment on diamond surfaces and their impact on the electronic structure, using wet and dry chemical approaches, would hence be of interest in engineering diamond as a semiconductor.

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Boron nitride (BN) is an exceptional material, and among its polymorphs, two-dimensional (2D) hexagonal and three-dimensional (3D) cubic BN (h-BN and c-BN) phases are most common. The phase stability regimes of these BN phases are still under debate, and phase transformations of h-BN/c-BN remain a topic of interest. Here, we investigate the phase stability of 2D/3D h-BN/c-BN nanocomposites and show that the coexistence of two phases can lead to strong nonlinear optical properties and low thermal conductivity at room temperature.

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Article Synopsis
  • Room temperature growth of two-dimensional van der Waals (2D-vdW) materials is crucial for advanced nanotechnology, minimizing thermal issues that can negatively impact electronic devices.
  • The study successfully demonstrated the room temperature growth of ultrawide-bandgap boron nitride (BN) using pulsed laser deposition, resulting in ordered nanosheet-like structures.
  • The h-BN nanosheets exhibit unique properties, including hydrophobicity, low friction, low refractive index, and single-photon quantum emission, suggesting their potential for numerous applications across various substrates.
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Realizing solution-processed heterostructures is a long-enduring challenge in halide perovskites because of solvent incompatibilities that disrupt the underlying layer. By leveraging the solvent dielectric constant and Gutmann donor number, we could grow phase-pure two-dimensional (2D) halide perovskite stacks of the desired composition, thickness, and bandgap onto 3D perovskites without dissolving the underlying substrate. Characterization reveals a 3D-2D transition region of 20 nanometers mainly determined by the roughness of the bottom 3D layer.

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Piezoelectricity in low-dimensional materials and metal-semiconductor junctions has attracted recent attention. Herein, a 2D in-plane metal-semiconductor junction made of multilayer 2H and 1T' phases of molybdenum(IV) telluride (MoTe ) is investigated. Strong piezoelectric response is observed using piezoresponse force microscopy at the 2H-1T' junction, despite that the multilayers of each individual phase are weakly piezoelectric.

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Article Synopsis
  • Researchers developed a biocomposite using a chitosan matrix reinforced with morphed graphene, achieving a 40-50% increase in yield and compressive strength compared to pure chitosan.
  • The mechanical properties, including fracture toughness, saw significant improvements, although Young's modulus decreased by about 10%.
  • These biocomposites are sustainable, compostable, and made from waste products, presenting a promising eco-friendly alternative to traditional plastics.
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A brief overview of quantum materials and their prospects for applications, in the near, mid, and far-term in the areas of quantum information science, spintronics, valleytronics, and twistronics and those involving topology are covered in this perspective. The material and processing challenges that will modulate the realism of the applications will be discussed as well.

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Two-dimensional (2D) materials are known to have low-friction interfaces by reducing the energy dissipated by sliding contacts. While this is often attributed to van der Waals (vdW) bonding of 2D materials, nanoscale and quantum confinement effects can also act to modify the atomic interactions of a 2D material, producing unique interfacial properties. Here, we demonstrate the low-friction behavior of magnetene, a non-vdW 2D material obtained via the exfoliation of magnetite, showing statistically similar friction to benchmark vdW 2D materials.

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New ways of directly using solar energy to charge electrochemical energy storage devices such as batteries would lead to exciting developments in energy technologies. Here, a two-electrode photo rechargeable Li-ion battery is demonstrated using nanorod of type II semiconductor heterostructures with in-plane domains of crystalline MoS and amorphous MoO . The staggered energy band alignment of MoS and MoO limits the electron holes recombination and causes holes to be retained in the Li intercalated MoS electrode.

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Despite decades of research, metallic corrosion remains a long-standing challenge in many engineering applications. Specifically, designing a material that can resist corrosion both in abiotic as well as biotic environments remains elusive. Here a lightweight sulfur-selenium (S-Se) alloy is designed with high stiffness and ductility that can serve as an excellent corrosion-resistant coating with protection efficiency of ≈99.

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Hexagonal boron nitride (h-BN) has emerged as a strong candidate for two-dimensional (2D) material owing to its exciting optoelectrical properties combined with mechanical robustness, thermal stability, and chemical inertness. Super-thin h-BN layers have gained significant attention from the scientific community for many applications, including nanoelectronics, photonics, biomedical, anti-corrosion, and catalysis, among others. This review provides a systematic elaboration of the structural, electrical, mechanical, optical, and thermal properties of h-BN followed by a comprehensive account of state-of-the-art synthesis strategies for 2D h-BN, including chemical exfoliation, chemical, and physical vapor deposition, and other methods that have been successfully developed in recent years.

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Cementitious structures exhibit high compression strength but suffer from inherent brittleness. Conversely, nature creates structures using mostly brittle phases that overcome the strength-toughness trade-off, mainly through internalized packaging of brittle phases with soft organic binders. Here, we develop complex architectures of cementitious materials using an inverse replica approach where a soft polymer phase emerges as an external conformal coating.

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Lithium batteries that could be charged on exposure to sunlight will bring exciting new energy storage technologies. Here, we report a photorechargeable lithium battery employing nature-derived organic molecules as a photoactive and lithium storage electrode material. By absorbing sunlight of a desired frequency, lithiated tetrakislawsone electrodes generate electron-hole pairs.

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The discovery of ferromagnetism in atomically thin layers at room temperature widens the prospects of 2D materials for device applications. Recently, two independent experiments demonstrated magnetic ordering in two dissimilar 2D systems, CrI and Cr Ge Te , at low temperatures and in VSe at room temperature, but observation of intrinsic room-temperature magnetism in 2D materials is still a challenge. Here a transition at room temperature that increases the magnetization in magnetite while thinning down the bulk material to a few atom-thick sheets is reported.

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Alkali and alkaline earth metal-ion batteries are currently among the most efficient electrochemical energy storage devices. However, their stability and safety performance are greatly limited when used with volatile organic liquid electrolytes. A solid state polymer electrolyte is a prospective solution even though poor ionic conductivity at room temperature remains a bottleneck.

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Since graphene, a variety of 2D materials have been fabricated in a quest for a tantalizing combination of properties and desired physiochemical behavior. 2D materials that are piezoelectric, i.e.

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