bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Confined and Free-Standing Perovskite Nanowires for X-Ray Detection
Authors: Wallentin Jesper 
Published: February 2024

Metal halide perovskites (MHPs) have shown excellent results in many applications, including X-ray scintillation detection. Nanowires could offer improved sensitivity by exploiting nanophotonic light guiding, and the MHP stability could be improved by growing nanowires physically protected in anodized aluminum oxide (AAO). We use a one-step solution low-temperature method to grow arrays of long single-crystalline CsPbBr3 nanowires in an AAO template. The diameters can be adjusted by the AAO template, ranging from 30 to 360 nm, and the length can be controlled up to 15 μm (Fig 1(a)) [1]. The nanowires show excellent stability, with no obvious lack in photoluminescence after months of storage in air. The X-ray scintillation shows no systematic degradation over 2 weeks of continuous X-ray exposure, but an unexpected positive correlation with room humidity. The excellent stability allows tomographic 3D X-ray imaging at better than 3 μm resolution [2].
Surprisingly, we find that free-standing CsPbBr3 nanowires can be obtained by the same method (Fig 1(b)) [3]. The length of the vertically aligned nanowires is controlled from 1 to 20 μm with the precursor amount. The nanowires are single-crystalline and exhibit excellent photoluminescence and clear light guiding (Fig 1(c)). Lithography methods for MHPs have been limited because of their solubility in polar solvents. However, we show that o-xylene can be used in a perovskite-compatible electron beam lithography (EBL) process based on nonpolar solvents [4]. Combining these results, we demonstrate single nanowire devices with excellent photoresponse. Recently, we have developed a gas-phase halide exchange method based on HCl or Cl2 to convert the green-emitting CsPbBr3 to blue-emitting CsPb(BrxCl1-x)3. [5]. Using the aforementioned EBL process, we selectively convert segments of nanowires to CsPb(BrxCl1-x)3 and create axially heterostructured nanowires (Fig 1(d)).
1 Z. Zhang, H. Dierks, N. Lamers et al., "Single-Crystalline Perovskite Nanowire Arrays for Stable X-ray Scintillators with Micrometer Spatial Resolution"
ACS Applied Nano Materials 5 (1), 881 (2022) http://doi.org/10.1021/acsanm.1c03575
2 H. Dierks, Z. Zhang, N. Lamers, and J. Wallentin, "3D X-ray microscopy with a CsPbBr3 nanowire scintillator"
Nano Res. 16 (1), 1084 (2023) https://doi.org/10.1007/s12274-022-4633-7
3 Z. Zhang, N. Lamers, C. Sun, C. Hetherington, I. G. Scheblykin, and J. Wallentin, "Free-Standing Metal Halide Perovskite Nanowire Arrays with Blue-Green Heterostructures"
Nano Lett. 22 (7), 2941 (2022) http://doi.org/10.1021/acs.nanolett.2c00137
4 N. Lamers, Z. Zhang, and J. Wallentin, "Perovskite-Compatible Electron-Beam-Lithography Process Based on Nonpolar Solvents for Single-Nanowire Devices"
ACS Applied Nano Materials 5 (3), 3177 (2022) http://doi.org/10.1021/acsanm.2c00188
5 N. Lamers, Z. Zhang, I. G. Scheblykin, and J. Wallentin, "Multisegment Heterostructured CsPb(Br1-xClx)3 Perovskite Nanowires using Gas-Phase Anion Exchange"
In review (2023)

Figure 1
(Invited) Growth of Hexagonal Boron Nitride by MOCVD for Electronic and Photonic Applications
Authors: Kim Jong Kyu 
Published: February 2024

Hexagonal boron nitride (h-BN) is a 2-dimensional (2D) layered insulating material. Thanks to its wide bandgap of ~6 eV and high thermal conductivity, h-BN has been widely utilized as an ideal substrate, gate dielectric material, passivation layer, and atomic tunnelling layer for 2D electronic devices. Recently, it has gained more attention as active material for photonics applications due to its potential for stable quantum emitters in the visible spectral range, as well as deep-ultraviolet emitters and detectors due to its exceptionally high internal quantum efficiency despite its indirect bandgap. However, mechanically exfoliated bulk h-BN and h-BN films grown on catalytic metal substrates by conventional chemical vapor deposition (CVD) systems have been mainly used to study the fundamental properties, lacking in scalability for practical implementation of h-BN.
Here, we exploit the scalable approach to grow h-BN on various substrates such as sapphire, Si, and GaN, by using metal-organic chemical vapor deposition (MOCVD). A few-layer h-BN films were successfully grown on those substrates. In particular, we successfully accomplished the conformal growth of few-layer h-BN over an array of Si-based nanotrenches with 45 nm pitch and the aspect ratio of ~ 7:1. Moreover, it was found that at a specific MOCVD growth condition, a very unique h-BN film can be grown on GaN substrates, in which few-layer h-BN film is suspended on GaN nanoneedles. The combination of state-of-the-art microscopic and spectroscopic analyses revealed that the suspended h-BN films exhibit unprecedented deep ultraviolet photoluminescence spectra with local variation in band-edge emission. In addition, the h-BN films show unprecedented atomic stacking configuration, the mechanism of which will be discussed with optical and structural characterizations and theoretical calculations.
(Invited) Thermoelectric Transport in Nanostructured 3D Topological Insulators and Stacked 2D Materials / Ferecrystals
Authors: Nielsch Kornelius 
Published: February 2024

Research in thermoelectric (TE) quantum structures was greatly propelled by the pre[1]diction in the early 1990s of a significant boost in TE efficiency by quantum size effects. Recently, research interest has shifted from quantum size effects in conventional semiconductors toward new types of quantum materials (e.g., topological insulators [TIs], Weyl and Dirac semimetals) characterized by their nontrivial electronic topology. Bi2Te3, Sb2Te3, and Bi2Se3, established TE materials, are also TIs exhibiting a bulk bandgap and highly conductive and robust gapless surface states. The signature of the nontrivial electronic band structure on the TE transport properties can be best verified in transport experiments using nanowires and thin films. However, even in nanograined bulk, the typical peculiarities in the transport properties of TIs can be seen. The signature of TI surface states on the thermoelectric properties of nanowire model systems will be discuss in depth and how these states can be modified by chemical modifications and in the vicinity of magnetic insulators.
In the second part, we will report a different material class of stacked 2D materials based on metal monochalcogenides (MMCs), topological insulators and non-van der Waals (nvW) 2D Materials called ferecrystals via atomic layer deposition (ALD). The ferecrystals can be tailored to exhibit unusual properties such as low thermal conductivity or electronic or magnetic properties. The electronic properties of the 2D materials are modified by the interactions between the interwoven layered and non-layered materials. We have developed ferecrystal combinations, where the 2D material is the electronically active or in-active layer by selection of the bandgap for each layer.

Figure 1
(Invited) Self-Powered Image Sensors Based on Vertical Van Der Waals 2H/1T' -MoTe2 Homojunctions
Authors: Hu Yunxia , Gao Zhaoli , Luo Zhengtang , Huo Xiaoyu 
Published: February 2024

Image sensors can convert optical images into electrical images, which play important roles in industrial application fields and emerging applications, including digital cameras, biomedical imaging, and machine visions. [1, 2] Compared to traditional three-dimensional rigid materials, two-dimensional (2D) materials with excellent electrical, optoelectrical, and mechanical properties exhibit great potentials in novel image sensors. This work aims to synthesize large scale van der Waals 1T’/2H MoTe2 homojunctions and fabricate image sensors for self-powered imaging functions. Firstly, a two-step chemical vapor deposition (CVD) method is adopted to synthesize the 1T’/2H MoTe2 homojunctions via tellurization process of molybdenum film. Secondly, the structural design of the self-powered photodetector based on 2H MoTe2 with asymmetric electrodes and the corresponding optoelectrical properties are investigated. [3] Thirdly, an image sensor consisting of a self-powered MoTe2 photodetectors array is constructed and exhibits excellent imaging functions with zero power electrical consumption. This work will open a new route to build image systems based on 2D materials, showing great opportunities in digital image systems with ultralow power consumption and excellent imaging functions.

Acknowledgement

This work was fully supported by a grant from the National Natural Science Foundation of China (Project No. 52022003).

References

[1] S. Goossens, G. Navickaite, C. Monasterio, S. Gupta, J. J. Piqueras, R. Pérez, G. Burwell, I. Nikitskiy, T. Lasanta, T. Galán, E. Puma, A. Centeno, A. Pesquera, A. Zurutuza, G. Konstantatos, F. Koppens, Broadband image sensor array based on graphene–CMOS integration. Nat. Photonics 11 (2017) 366-371.
[2] M. Bigas, E. Cabruja, J. Forest, J. Salvi, Review of CMOS image sensors. Microelectron. J. 37 (2006) 433-451.
[3] H. Qiao, Z. Y. Huang, X. H. Ren, S. H. Liu, Y. P. Zhang, X. Qi, H. Zhang, Self‐powered photodetectors based on 2D materials. Adv. Opt. Mater. 8 (2019) 1900765.
(Invited) Photoactive Inorganic Nanosystems for Environmental and Energy-Related Applications
Authors: Moretti Elisa 
Published: February 2024

Nowadays, one of the main technological challenges that we are facing is the ability to provide a sustainable supply of clean energy and, among all renewable sources, solar energy displays the greatest potential. Recently, the development of novel synthetic strategies has led to the preparation of nanostructured materials displaying unique properties compared to the bulk counterpart systems, with controlled and tunable morphologies able to enhance the activity and selectivity of a heterogenous process.
This talk will focus on the importance of tuning the morphological features of a catalyst as a strategy to improve its photoactivity, focusing on how rationally designing inorganic materials at the nanoscale can lead to shapes and structures suitable to enhance the performance of industrially and environmentally important processes. The talk will discuss some energy and environmental applications that can be addressed by multi-component systems synthesized via the bottom–up approach, highlighting their structure-reactivity relationship. Photocatalytic H2 production and purification and drugs degradation will be presented as successful cases history [1-3].
[1] E. Moretti, L. Storaro, A. Talon, P. Riello, A. Infantes Molina, E. Rodríguez-Castellón, Appl. Catal. B: Environmental 168 (2015) 385.
[2] M. Telkhozhayeva, B. Hirsch, R. Konar, E. Teblum, R. Lavi, M. Weitman, B. Malik, E. Moretti, G.D. Nessim, Appl. Catal. B: Environmental 318 (2022) 121872.
[3] L. Liccardo, M. Bordin, P.M. Sheverdyaeva, M. Belli, P. Moras, A. Vomiero, E. Moretti, Adv. Funct. Mater. (2023) in press.
(Invited) Wireless Healthcare Flexible Sensor System
Authors: Takei Kuniharu 
Published: February 2024

Daily continuous health condition monitoring is now of great interests using multi-functional flexible sensors. In particular, vital signals from skin are the most convenient way to measure continuously data collections during daily life. For this purpose, flexible sensor sheets allow it to detect multiple information from skin precisely due to conformable covering over skin surface. To realize this platform, multiple developments including flexible sensors, wireless system, and edge system to analyse huge size of datasets are required. In this talk, I introduce a wireless multiple sensor sheet with real-time data analyses on a smartphone as an edge system. The system has a function to display real-time analysed results on a smartphone to notify the users about their conditions.
Although a lot of researches and developments are still required for practical application, these studies may help to open a door for the next step of flexible electronics.
In-Situ Quantification of the Ageing Dynamics in Lithium-Ion Cells up to Failure-Near Conditions
Authors: Scharpmann Philippa , Leonhardt Robert , Tichter Tim , Schmidt Anita , Krug von Nidda Jonas 
Published: February 2024

Implementing end-of-life (EOL) lithium-ion batteries from automotive applications in stationary energy storages is of utmost relevance for a sustainable handling of scarce resources. Beneficial from an economic and ecological perspective, such second-life applications urgently require a guarantee for safe operation. Unlike the state of health (SOH), defined by classical performance indicators such as capacity and voltage, the state of safety (SOS) of an aged battery cannot be assessed straightforward. Its determination requires a plethora of cells to be tested which is a particular challenge for new technologies with limited access to EOL batteries.
For providing cells with a defined SOH at a reasonable timescale, we herein propose a novel method of greatly accelerating the ageing process of lithium-ion batteries. In a preliminary test series, lithium-ion NMC pouch cells are exposed to incrementally increasing temperatures, current rates and/or states of charge (SOC), until thermal runaway is induced. In this manner, the critical state in proximity to cell failure is spotted for individual and combined stress parameters. Based on this knowledge, cell-specific test parameters for heavily accelerated ageing are developed. In this protocol, electrical abuse conditions are defined by over/under charging and high current rates. Typically, the cells are cycled utilizing a depth of discharge above 100 %.
The accelerated aging dynamics under these critical conditions are monitored by systematic capacity, open circuit voltage and electrochemical impedance spectroscopy (EIS) measurements. This enables a comparative assessment of the electrical behaviour, following conventional vs. heavily accelerated ageing. Such knowledge will in turn help to define the threshold to which cyclic ageing can be accelerated without changing the characteristic degradation mechanisms of lithium-ion batteries.
Investigation of Water Ingress Driven Circuit Board Faults As a Contributory Factor to Battery Thermal Runaway
Authors: Johns Phillip , Torelli Daniel 
Published: February 2024

Recent high-profile examples of battery fires in electric vehicles (EV’s) during the aftermath of Hurricane Ian [1] have led to increased public visibility of the susceptibility of EV batteries to thermal failure due to water immersion or ingress.
Although clearly an issue for manufacturers and users of automotive EV’s, this issue poses a particular challenge in the rapidly increasing micromobility market with nearly 800 million battery powered 2- and 3-wheeled vehicles (such as e-bikes or scooters) expected to be in operation by 2040 [2]. With privately owned micromobility vehicles generally not subject to the rigorous servicing or maintenance schedules of automotive EV’s, and fleets of rented e-bikes / scooters subjected to prolonged rough handling and environmental exposure, the risk of failure in these vehicles due to improper handling, water ingress or mechanical abuse is very real.
Testing and failure recreation of thermal runaway in lithium-ion based micromobility battery packs within Exponent’s European laboratory (London) has shown that even small amounts of moisture ingress to sensitive electronic components of the battery pack, such as the battery protection circuitry, can lead to thermal runaway of the cells within the battery pack. Such failures are often highly dependent on battery pack design (and physical condition) and may only manifest in the days or weeks after water immersion or ingress.
The study presented here investigated specific conditions and behaviours of saltwater ingress-driven circuit board faults in lithium-ion battery packs, and demonstrated localised temperature increases of ~100 °C, even at relatively low fault currents (mA’s), showing the potential for circuit board faults to propagate to cell thermal runaway.
Further studies investigated the effect of full, partial and targeted immersion of lithium-ion battery packs in 5 wt% NaCl solution, demonstrating the influence of the volume of water ingress and ingress location within the battery pack on the potential for battery thermal runaway. This paper will also discuss design aspects and/or mitigation methods to protect from such failure modes.
[1] - https://content.govdelivery.com/accounts/USDHSFACIR/bulletins/333744b
[2] - https://www.faraday.ac.uk/wp-content/uploads/2023/02/Faraday_Insights_16_FINAL.pdf
Challenges and Solutions for Integration of Energy Storage Systems in Hot Desert Regions
Authors: Maher Kenza 
Published: February 2024

The increasing utilization of solar renewable energy sources in the Gulf Cooperation Council (GCC) regions, including countries such as Saudi Arabia, the UAE, and Qatar, highlights the pressing need for energy storage systems (ESS) to ensure grid stability. ESS can store excess energy during peak generation and supply it during periods of low generation or high demand. However, the harsh environmental conditions and extreme temperatures that are typical of hot desert regions can impact the performance and lifespan of ESS, creating unique integration challenges.
Our work explores these challenges and offers solutions for integrating energy storage systems in hot desert regions. Our research shows that while the integration of ESS in hot desert regions is technically feasible and economically viable, it requires careful planning, design, and maintenance to ensure optimal performance and longevity. The solutions we present in this work can provide valuable guidance for engineers, policymakers, and stakeholders who are working towards a sustainable and resilient energy future in hot desert regions.
During the presentation, I will delve into the specific challenges that the harsh environmental conditions and extreme temperatures in hot desert regions pose for the integration of energy storage systems. I will provide examples of how these challenges can impact the performance and lifespan of ESS. Furthermore, I will highlight the solutions that we have identified and presented in our research, which can help overcome the challenges and improve the effectiveness of energy storage systems in hot desert regions.
(Invited) Improving Certainty in Battery Safety Profiles through Early-Stage Evaluation
Authors: Bates Alex Martin , Albertus Paul , Jeevarajan Judith , Mukherjee Partha P. , Torres-Castro Loraine 
Published: February 2024

There is currently a great desire to reduce carbon emissions through electrification of all transportation sectors by utilizing battery energy storage. However, existing technology is unable to meet the performance target demands of certain transportation sectors (e.g., aviation). As a result, and due to a growing demand for conventional Li-ion battery materials, there is significant motivation to generate new battery technologies. During early-stage of development, the primary focus is demonstrating the achievement of performance metrics for the anticipated application. Once performance metrics have been demonstrated, the focus turns to scale-up. It isn’t until the later stages of development, perhaps even during the push for large scale manufacturing, that safety is more closely analyzed. At that stage, a significant amount of research dollars has been invested into that technology. To complicate matters, it is widely understood that the safety profile of large format cells (e.g., multi-layer pouch cells) can be significantly different than the safety profile of small format cells (e.g., coin cells) of the exact same chemistry.
The work presented here examines the gap that exists in the understanding of a commercial-scale full cell's safety characteristics through a combination of characterization, experiments, and modeling using only information gained at the lab-scale, early-stage development (i.e., materials and small format cells). Characterization and experiment will be developed in such a way as to determine and quantify key metrics that will be utilized as modeling inputs. A modeling framework will utilize those key metrics to predict the large format safety profile of a specific chemistry. Experimental work, where cells are exposed to abusive conditions, will allow for the refinement of input parameters and refinement of the modeling framework to increase certainty in large format safety profile. This talk will highlight the planned approach to utilize a battery technology’s materials and small format cells to develop a picture of what may be expected in the safety profile of a large format cell.
Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia LLC, a wholly owned subsidiary of Honeywell International Inc. for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.
Failure Modes in Sulfide-Based All Solid-State Batteries (ASSB) Investigated By Operando SEM
Authors: Davoisne Carine , Yadav Neelam , Morcrette Mathieu 
Published: February 2024

Studies on solid state batteries (ASSB) which began back in 190’s has seen a tremendous growing interest for multiple reasons such as the safety and the ability to use the metallic anodes for enhancing the gravimetric energy density. However, it exists different issues linked with poor performance of the batteries, which could be the results of interfacial challenges such as poor ion transport, dendrite formation, electrochemical degradation and chemo-mechanical degradation[1]. Among the potential parameters impacting the cycling process, the influence of the particle size of solid electrolyte is not well studied.
In this study, we focused on sulfide-based SEs particle size distribution and its impact on electrochemical performance by investigating from the morphological point of view via operando SEM. A batch of Argyrodite (Li6PS5Cl (LPSCl)) was sieved to obtain two batches of particles range (0,5-20µm and 50-150µm). The AASBs were prepared using the two particles size distribution while keeping the anode (lithium metal), cathode (MA: NMC) composite formation and the fabrication process constant. The different morphological and chemical evolutions were monitored in real time by scanning electron microscopy (SEM) and X-ray energy dispersive spectroscopy (EDX) to obtain a complete of the different modification throughout the battery components and their interfaces. To do so, a home-made electrochemical cell was developed to perform in-situ and operando cycling in the SEM.
From the two particles sized distribution, the one with the large particles have better electrochemical performance. From morphological point of view at the cathode composite electrode, the formation of a cathode electrolyte interface is visible in the different batteries but is more developed in the case of small sized particles. In the solid electrolyte, the type of cracks differs with relatively strait feature for small particles and sinuous one for large one. At the anodic interface, a lost in contact between the SE separator and the lithium is observed and increased with the cycling process with a higher impact for the small particles (Figure 1.a and b). By investigating further, the formation of dendrites with different morphologies are visible at the anodic interfaces (Figure1.c).
We categorized the observed changes into three modes: (i) electrical failure by the formation of lithium dendrites of different morphologies following the ES going up to short circuit in the case of small particles, (ii) mechanical failure by the formation of cracks in the electrolyte whose shape and propagation strongly depend on the distribution particles size and (iii) electrochemical failure with the formation of solid electrolyte interphases on the surface of the active material. The main obstacles for the use of lithium metal are related to the propagation of lithium dendrites and thus to the mechanical instability of solid electrolytes.