BINA

Two-dimensional (2D) halide perovskites, HaPs, can provide chemical stability to three-dimensional (3D) HaP surfaces, protecting them from exposure to ambient species and from reacting with contacting layers. Both actions occur with 2D HaPs, with the general stoichiometry R2PbI4 (R: long or bulky organic amine) covering the 3D ones. Adding such covering films can also boost power conversion efficiencies of photovoltaic cells by passivating surface/interface trap states. For maximum benefit, we need conformal ultrathin and phase-pure (n = 1) 2D layers to enable efficient tunneling of photogenerated charge carriers through the 2D film barrier. Conformal coverage of ultrathin (<10 nm) R2PbI4 layers on 3D perovskites is challenging with spin coating; even more so is its upscaling for larger-area devices. We report on vapor-phase cation exchange of the 3D surface with the R2PbI4 molecules and real-time in situ …

Spin–orbit coupling (SOC) combined with broken inversion symmetry plays a key role in inducing Rashba effect. The combined spontaneous polarization and Rashba effect enables controlling a material's spin degrees of freedom electrically. In this work, we investigated an electronic band structure for several combinations of TiX 2 monolayers (X= Te, S, and Se): TiTe 2/TiSe 2, TiTe 2/TiS 2, and TiSe 2/TiS 2. Based on the observed orbital hybridization between the different monolayers in these heterostructures (HSs), we conclude that the most significant Rashba splitting occurs in TiSe 2/TiS 2. Subsequently, we used fluorine (F) as an adatom over the surface of TiSe 2/TiS 2 at hollow and top sites of the surface to enhance the Rashba intensity, as the F adatom induces polarization due to the difference in charge distribution. Furthermore, by increasing the number of F atoms on the surface, we reinforced the band …

We introduce a planar Hall effect magnetometer in the form of a parallel array of permalloy-based elliptical sensors. The number of ellipses in the array and other fabrication parameters are optimized with the support of numerical simulations. We obtain equivalent magnetic noise (EMN) of 16 pT/ffiffiffiffiffiffi Hz p at 100 Hz, 25 pT/ffiffiffiffiffiffi Hz p at 10 Hz, 98 pT/ffiffiffiffiffiffi Hz p at 1 Hz, and 470 pT/ffiffiffiffiffiffi Hz p at 0.1 Hz. The exceptional EMN without the use of magnetic flux concentrators highlights the advantages of the design. The presented magnetometer, characterized by its simplicity, affordability, and ability to operate at room temperature, is anticipated to be useful for applications requiring pT resolution.

Accessing the low-energy non-equilibrium dynamics of materials with simultaneous spatial and temporal resolutions has been a bold frontier of electron microscopy in recent years. One of the main challenges is the ability to retrieve extremely weak signals while simultaneously disentangling amplitude and phase information. Here, we present an algorithm-based microscopy approach that uses light-induced electron modulation to demonstrate the coherent amplification effect in electron imaging of optical near-fields. We provide a simultaneous time-, space-, and phase-resolved measurement in a micro-drum made from a hexagonal boron nitride membrane, visualizing the sub-cycle spatio-temporal dynamics of 2D polariton wavepackets therein. The phase-resolved measurement reveals vortex-anti-vortex singularities on the polariton wavefronts, together with an intriguing phenomenon of a traveling wave mimicking the amplitude profile of a standing wave. Our experiments show a 20-fold coherent amplification of the near-field signal compared to conventional electron near-field imaging, resolving peak field intensities of ~W/cm2 (field amplitude of few kV/m). As a result, our work opens a path toward spatio-temporal electron microscopy of biological specimens and quantum materials - exciting yet sensitive samples, which are currently difficult to investigate.

Practical implementation of alkali metal batteries currently still faces formidable challenges because of the dendrite growth upon continuous charge/discharge processes and the associated unstable solid–electrolyte interphase. Herein, it is reported that dendrites can be fundamentally mitigated in lithium and sodium metal batteries by regulating the Li+ and Na+ flux using a glass fiber (GF) separator impregnated with polytetrafluoroethylene nanospheres (PTFE‐NSs), which results in homogeneous deposition of Li and Na during charging. The COMSOL Multiphysics simulations reveal that the introduction of negatively charged PTFE‐NSs into the GF separator enhances the local electric field near the anode, thereby boosting the transfer of cations. It is demonstrated that Li//Li and Na//Na symmetric cells utilising a PTFE‐GF separator show outstanding cycle stability of 1245 and 2750 h, respectively, at 0.5 mA cm−2 …

Two-dimensional (2D) semiconducting heterojunction chemical sensors are in high demand because of their enhanced response, stability, and selectivity. However, fine-tuning heterojunctions using vapor deposition growth still needs further research. Our present study focuses on the ambient pressure chemical vapor deposition (CVD) synthesis of hexagonal tungsten sulfide-tungsten selenide (WS2–WSe2) p–p heterojunctions (as a 2D–2D arrangement). We use the liquid-phase exfoliation method to disperse bulk WS2 and WSe2 and decorate large flakes of WS2 with smaller WSe2 nanosheets in CVD. Electron microscopy and related surface investigations reveal their homogeneity on drop-casting. Two drops from the exfoliated heterojunction dispersion were drop-cast on a transducer to study the NO2 response and related sensing properties. The sensor showed long-term stability (>2 months), even at high …

Spin–orbit coupling (SOC) combined with broken inversion symmetry plays a key role in inducing Rashba effect. The combined spontaneous polarization and Rashba effect enables controlling a material's spin degrees of freedom electrically. In this work, we investigated an electronic band structure for several combinations of TiX 2 monolayers (X= Te, S, and Se): TiTe 2/TiSe 2, TiTe 2/TiS 2, and TiSe 2/TiS 2. Based on the observed orbital hybridization between the different monolayers in these heterostructures (HSs), we conclude that the most significant Rashba splitting occurs in TiSe 2/TiS 2. Subsequently, we used fluorine (F) as an adatom over the surface of TiSe 2/TiS 2 at hollow and top sites of the surface to enhance the Rashba intensity, as the F adatom induces polarization due to the difference in charge distribution. Furthermore, by increasing the number of F atoms on the surface, we reinforced the band …

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Gene-editing strategies involving engineered nucleases [ie, zinc-finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), meganucleases, and clustered regularly interspaced short palindromic repeat (CRISPR) associated nuclease 9 (Cas9)] have made a substantial impact on biological research and offer great therapeutic potential. While CRISPR/Cas9 is the most versatile of these systems it has also exhibited a propensity for off-target activity (Hockemeyer et al., 2011; Mussolino et al., 2011; Cradick et al., 2013; Fu et al., 2013; Hsu et al., 2013; Mali et al., 2013; Pattanayak et al., 2013; Yang et al., 2013; Cho et al., 2014; Lin et al., 2014; Zhang et al., 2014; Liang et al., 2015; Aryal et al., 2018). Understanding and mitigating the off-target activity in the clinical use of gene therapy is of particular importance because off-target effects may not be limited to transient events but may be pertinent to the lifetime of edited cells. Off-target detection methodologies are necessary because the functionality of gene-editing nucleases in general and the CRISPR system in particular are not fully understood. While some studies have indicated that CRISPR is more susceptible to unintended cleavage events than zinc finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs), the versatility of CRISPR targeting has rapidly made it the genome editing tool of choice (Deng et al., 2018; Huang et al., 2018; Panfil et al., 2018; Foss et al., 2019; Gao et al., 2019; Karimian et al., 2019; Li et al., 2019). There is data to suggest that the off-target proclivity of CRISPR guide RNAs (gRNAs) can be overcome with proper design …

Gene-editing strategies involving engineered nucleases [ie, zinc-finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), meganucleases, and clustered regularly interspaced short palindromic repeat (CRISPR) associated nuclease 9 (Cas9)] have made a substantial impact on biological research and offer great therapeutic potential. While CRISPR/Cas9 is the most versatile of these systems it has also exhibited a propensity for off-target activity (Hockemeyer et al., 2011; Mussolino et al., 2011; Cradick et al., 2013; Fu et al., 2013; Hsu et al., 2013; Mali et al., 2013; Pattanayak et al., 2013; Yang et al., 2013; Cho et al., 2014; Lin et al., 2014; Zhang et al., 2014; Liang et al., 2015; Aryal et al., 2018). Understanding and mitigating the off-target activity in the clinical use of gene therapy is of particular importance because off-target effects may not be limited to transient events but may be pertinent to the lifetime of edited cells. Off-target detection methodologies are necessary because the functionality of gene-editing nucleases in general and the CRISPR system in particular are not fully understood. While some studies have indicated that CRISPR is more susceptible to unintended cleavage events than zinc finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs), the versatility of CRISPR targeting has rapidly made it the genome editing tool of choice (Deng et al., 2018; Huang et al., 2018; Panfil et al., 2018; Foss et al., 2019; Gao et al., 2019; Karimian et al., 2019; Li et al., 2019). There is data to suggest that the off-target proclivity of CRISPR guide RNAs (gRNAs) can be overcome with proper design …

Two-dimensional (2D) halide perovskites, HaPs, can provide chemical stability to three-dimensional (3D) HaP surfaces, protecting them from exposure to ambient species and from reacting with contacting layers. Both actions occur with 2D HaPs, with the general stoichiometry R2PbI4 (R: long or bulky organic amine) covering the 3D ones. Adding such covering films can also boost power conversion efficiencies of photovoltaic cells by passivating surface/interface trap states. For maximum benefit, we need conformal ultrathin and phase-pure (n = 1) 2D layers to enable efficient tunneling of photogenerated charge carriers through the 2D film barrier. Conformal coverage of ultrathin (<10 nm) R2PbI4 layers on 3D perovskites is challenging with spin coating; even more so is its upscaling for larger-area devices. We report on vapor-phase cation exchange of the 3D surface with the R2PbI4 molecules and real-time in situ …

Two-dimensional (2D) halide perovskites, HaPs, can provide chemical stability to three-dimensional (3D) HaP surfaces, protecting them from exposure to ambient species and from reacting with contacting layers. Both actions occur with 2D HaPs, with the general stoichiometry R2PbI4 (R: long or bulky organic amine) covering the 3D ones. Adding such covering films can also boost power conversion efficiencies of photovoltaic cells by passivating surface/interface trap states. For maximum benefit, we need conformal ultrathin and phase-pure (n = 1) 2D layers to enable efficient tunneling of photogenerated charge carriers through the 2D film barrier. Conformal coverage of ultrathin (<10 nm) R2PbI4 layers on 3D perovskites is challenging with spin coating; even more so is its upscaling for larger-area devices. We report on vapor-phase cation exchange of the 3D surface with the R2PbI4 molecules and real-time in situ …

In quantum mechanics, a quantum system is irreversibly collapsed by a projective measurement. Hence, delicately probing the time evolution of a quantum system holds the key to understanding curious phenomena. Here we experimentally explore an anomalous time evolution, where, illustratively, a particle disappears from a box and emerges in a different box, with a certain moment in which it can be found in neither of them. In this experiment, we directly probe this curious time evolution of a single photon by measuring up to triple-operator sequential weak values using a novel probeless scheme. The naive interpretation provided by single-operator weak values seems to imply the “disappearance” and “re-appearance” of a photon as theoretically predicted. However, double- and triple-operator sequential weak values, representing temporal correlations between the aforementioned values, show that spatial …

In terms of sustainable use, halide perovskite (HaP) semiconductors have a strong advantage over most other classes of materials for (opto)electronics, as they can self-heal (SH) from photodamage. While there is considerable literature on SH in devices, where it may not be clear exactly where damage and SH occur, there is much less on the HaP material itself. Here we perform “fluorescence recovery after photobleaching” (FRAP) measurements to study SH on polycrystalline thin films for which encapsulation is critical to achieving complete and fast self-healing. We compare SH in three photoactive APbI3 perovskite films by varying the A-site cation ranging from (relatively) small inorganic Cs through medium-sized MA to large FA (the last two are organic cations). While the A cation is often considered electronically relatively inactive, it significantly affects both SH kinetics and the threshold for photodamage. The …

A two-dimensional (2D) solid-state random laser emitting in the visible is demonstrated, in which optical feedback is provided by a controlled disordered arrangement of air-holes in a dye-doped polymer film. We find an optimal scatterer density for which threshold is minimum and scattering is the strongest. We show that the laser emission can be red-shifted by either decreasing scatterer density or increasing pump area. We show that spatial coherence is easily controlled by varying pump area. Such a 2D random laser provides with a compact on-chip tunable laser source and a unique platform to explore non-Hermitian photonics in the visible.

Quantum walks underlie an important class of quantum computing algorithms, and represent promising approaches in various simulations and practical applications. Here we design stroboscopically monitored quantum walks and their subsequent graphs that can naturally boost target searches. We show how to construct walks with the property that all the eigenvalues of the non-Hermitian survival operator, describing the mixed effects of unitary dynamics and the back-action of measurement, coalesce to zero, corresponding to an exceptional point whose degree is the size of the system. Generally, the resulting search is guaranteed to succeed in a bounded time for any initial condition, which is faster than classical random walks or quantum walks on typical graphs. We then show how this efficient quantum search is related to a quantized topological winding number and further discuss the connection of the problem …

Publisher Correction: Optical reciprocity induced wavefront shaping for axial and lateral shifting of focus through a scattering Page 1 1 Vol.:(0123456789) Scientific Reports | (2023) 13:7525 | https://doi.org/10.1038/s41598-023-32998-3 www.nature.com/scientificreports Publisher Correction: Optical reciprocity induced wavefront shaping for axial and lateral shifting of focus through a scattering medium Abhijit Sanjeev , Vismay Trivedi & Zeev Zalevsky Correction to: Scientific Reports https:// doi. org/ 10. 1038/ s41598- 022- 10378-7, published online 16 April 2022 The original version of this Article contained an error in Eq. 1, where the equation contained wrong placements of bracket, a misplaced matrix, and devoid of the power M. now reads: ∗ 0 0 ⋮ 0 ⋮ 0 0 0 ⋮ 0 ⋮ 0 (1) (Free Space Propagation Matrix) (Phase Scattering Matrix) OPEN Page 2 2 Vol:.(1234567890) Scientific Reports | (2023) 13:7525 | https://doi.org/…

The term defect tolerance (DT) is used often to rationalize the exceptional optoelectronic properties of Halide Perovskites, HaPs, and their devices. Even though DT lacked direct experimental evidence, it became fact in the field. DT in semiconductors implies tolerance to structural defects without the electrical and optical effects (eg, traps), associated with such defects. We present first direct experimental evidence for DT in Pb HaPs by comparing the structural quality of 2D, 2D_3D, and 3D Pb HaP crystals with their optoelectronic characteristics using high sensitivity methods. Importantly, we get information from the material bulk, because we sample at least a few 100 nm, up to several micrometer, from the sample surface, which allows assessing intrinsic bulk (and not only surface) properties of HaPs. The results point to DT in 3D, to a lesser extent in 2D_3D, but not in 2D Pb HaPs. We ascribe such dimension …