The altermagnetic materials have emerged as model systems for studying spin split electronic structures, yet controlled epitaxial growth on technologically relevant substrates remains challenging. Among the known candidates, MnTe stands out as a prominent altermagnetic material owing to its layered structure and high Neel temperature. Here, we report the molecular beam epitaxy (MBE) growth of high quality alpha MnTe thin films on GaAs(111)B substrates and provide a comprehensive analysis of the growth evolution and structural properties. Raman spectroscopy reveals multiple vibrational features of alpha MnTe including modes near 121, and 140 1/cm. Combined with first principles phonon calculations, these features are identified as the Raman-active phonons of the hexagonal NiAs type lattice. Our results show that the high crystalline quality of MBE grown alpha MnTe enables the complete experimental resolution of all symmetry allowed Raman active phonon modes, highlighting epitaxial alpha MnTe as a robust thin film platform for investigating altermagnetism and its lattice coupled excitations.

Two-dimensional Ruddlesden-Popper perovskites have emerged as promising materials for optoelectronic synapse applications due to their unique quantum confinement effects, tunable band gap, excellent photoresponse, and enhanced environmental stability. Their layered structure enables efficient charge transport and light absorption, which are essential for mimicking synaptic functionalities. Here, we report a photonic synapse device using Ruddlesden-Popper perovskite nanocrystals (RPNCs) grown inside the inner channels of multiwalled carbon nanotubes (MWCNTs), a unique approach that enhances the environmental stability and charge transfer efficiency. The fabricated device demonstrates synaptic functionalities, including paired-pulse facilitation (PPF), synaptic time-dependent plasticity (STDP), and long-term potentiation and depression (LTP/LTD), with memory retention exceeding 1000 s. Furthermore, our CNN-based image recognition study achieved 92% accuracy on MNIST and 85% accuracy on F-MNIST, highlighting the potential for neuromorphic computing applications. This approach offers significant advantages in material stability and low-power operation, making it a promising candidate for future optoelectronic and artificial vision systems.

The innovations in electrochemical energy storage (EES) technologies to enhance the energy density, power density, and cycle life have brought forth the study of the impact of an external stimulus on EES devices' performance. This review critically examines the recent advancements in EES technologies, focusing on the enhancement of device performance due to the application of magnetic stimuli. Innovative fabrication techniques are discussed and analyzed to determine the electrochemical performance of EES devices subjected to magnetic fields. A comprehensive overview of the fundamental mechanisms involved, such as the reduction of charge transfer resistance at interfaces, inhibition of dendritic growth during electrode plating/stripping, enhanced mass transport of ionic species in electrolytes, and increased adsorption of reactive species at the electrical double layer due to a magnetic field, is also given. These processes collectively contribute to improved kinetic rates and overall electrochemical reaction mechanisms. The influence of magnetic stimuli is shown to significantly enhance energy storage capacity, cycling stability, and lifespan of EES devices, underscoring the potential of this approach in advancing energy storage technologies.

Sulfide-based solid-state electrolytes (SBSSEs) offer a promising solution to mitigate overcharging, overheating, and mechanical degradation issues associated with organic liquid electrolytes in lithium-ion batteries (LIBs). The ionic conductivity (IC) of SBSSEs has been enhanced through the incorporation of various dopants. Our dataset comprises ten features, including seven experimental results and three elemental properties of the dopants. Pearson correlation coefficient reveals that the concentration of dopant and electronegativity can influence the IC of SBSSEs. We applied three different machine learning models for regression analysis. Among them, the XGBoost model demonstrated superior predictive performance, achieving a R2 value of 0.83 in forecasting the discharge capacity of SBSSE-based LIBs. It is also observed that "Current" and IC can play a major role in determining the performance of the SBSSEs. These findings provide valuable insights for designing optimized SBSSEs before experimental synthesis, helping researchers in the development of next-generation solid-state electrolytes.

Zinc-ion batteries (ZIBs) are considered as a cheaper, non-toxic and safer alternative to lithium-ion batteries (LIBs). Manganese dioxide (MnO2) is one of the most viable cathode materials for aqueous electrolyte based ZIBs. The addition of different dopants in the MnO2 cathode material can significantly change its physical properties and electrochemical performance in ZIBs. In this study, we collected about 603 papers from which we selected 57 ZIB published papers related to doped MnO2 as a cathode material. The dataset consists of a total of eleven features (ten input features and one target) in which six features are related to battery properties and five features are related to the elemental properties of the dopants. The Pearson correlation plot is considered to investigate the correlation between different features, and it is observed that the electronegativity and first-ionization energy of the dopant have a positive relation with discharge capacity (DC). Both classification and regression treatment are applied to our dataset using different machine learning models such as XGBoost, random forest (RF), and K-nearest Neighbors. The RF model can classify DC with an accuracy of 0.72 into three predefined grades. In the regression analysis, the XGBoost model can predict DC with an R2 value of 0.92. Finally, the findings of this study can be utilized to predict the performance of doped MnO2 before synthesizing it in the laboratory.

In recent years, supercapacitors have received enormous popularity as energy storage devices due to their high power density and long-lasting cycle life compared to Lithium-Ion batteries and other similar energy storage devices. To attain high energy density, pseudocapacitive materials are being primarily investigated for asymmetric configuration-based supercapacitors. While most of the research is focused on finding new pseudocapacitive materials with higher specific capacitance, only very limited knowledge is available about how high voltage can be achieved in supercapacitors. Here, we present a comprehensive review of the mechanism of operation of the asymmetric supercapacitors. We discuss in detail the factors affecting the voltage window of the asymmetric supercapacitors like 1) the work function of the electrodes, 2) the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels of the electrolyte and 3) hydrogen and oxygen evolution overpotentials. We included an in-depth review of how work function originates in pseudocapacitive electrodes and its relation to Fermi level and electronegativity. Though transition metal oxides and carbon-based materials are used as base materials for this study, their application can be extended to any electrode-active material as long as it operates on the pseudocapacitive principle.

Nanomaterials have superior electronic, optical, and mechanical properties making them highly suitable for a range of applications in optoelectronics, biomedical fields, and photonics. Nanomaterials-based IR detectors are rapidly growing due to enhanced sensitivity, wide spectral range, and device miniaturization compared to commercial photodetectors. This review paper focuses on the significant role of nanomaterials in infrared detection, an area critical for enhancing night vision and health monitoring technologies. The latest advancements in IR photodetectors that employ various nanomaterials and their hybrids are discussed. The manuscript covers the operational mechanisms, device designing, performance optimization strategies, and material challenges. This review aims to provide a comprehensive overview of the current developments in nanomaterial-based IR photodetectors and to identify key directions for future research and technological advancements.

Supercapacitors are fast-charging energy storage devices of great importance for developing robust and climate friendly energy infrastructures for the future. Research in this field has seen rapid growth in recent years, therefore consistent reporting practices must be implemented to enable reliable comparison of device performance. Although several studies have highlighted the best practices for analysing and reporting data from such energy storage devices, there is yet to be an empirical study investigating whether researchers in the field are correctly implementing these recommendations, and which assesses the variation in reporting between different laboratories. Here we address this deficit by carrying out the first interlaboratory study of the analysis of supercapacitor electrochemistry data. We find that the use of incorrect formulae and researchers having different interpretations of key terminologies are major causes of variability in data reporting. Furthermore we highlight the more significant variation in reported results for electrochemical profiles showing non-ideal capacitive behaviour. From the insights gained through this study, we make additional recommendations to the community to help ensure consistent reporting of performance metrics moving forward.

Metal oxide nanostructures exhibit excellent properties, which make them a promising candidate for a broad range of green energy applications, including energy storage. In this work, asymmetric supercapacitor has been designed by using ZnO@stainless steel (SS) nanocauliflower as positive (Cathode) electrode and reduced graphene oxide rGO@Ni electrodes negative (Anode) electrode. The thin film electrode of ZnO was synthesized by reactive DC magnetron sputtering whereas rGO electrode was deposited via electrodeposition process. Furthermore, electrochemical kinetics of deposited thin film electrodes were done in 6 M aqueous KOH electrolyte solution. This novel supercapacitor rGO@Ni//ZnO@SS shows better capacitive performance than other nanostructured metal oxides. The as-fabricated ASCs exhibit comparably good electrochemical performance, including good capacitive values (within the range of 0-1.4 V) and long cycle stability (89.5% after 5000 cycles). The ASC offers good energy density of 23 Wh/kg at an optimum power density of 156 W/kg in 6 M KOH aqueous electrolyte, which shows comparably better results than the other reported ASCs. The excellent performance of nanostructured ASCs has momentous potential application in electric vehicles and in portable electronics.

Quantum dots and carbon nanotubes are advanced nanomaterials that show excellent electrical, mechanical, and optical characteristics. This paper proposes perovskite quantum dots (PQDs) grown on the lattice of Multi-Wall Carbon Nanotubes (MWCNTs) as an efficient gas sensor. The developed sensor shows ethanol selectivity when tested with methanol, hexane, benzene, and ethyl acetate at room temperature. It exhibited fast response and recovery times of 15.17 and 2.64 s, respectively, at 10 ppm ethanol with 90% relative humidity. Essential sensor characteristics like sensitivity, stability, repeatability, and scalability are achieved in these sensors. These remarkable sensor characteristics make PQDs/MWCNTs highly attractive for real-world ethanol monitoring applications at ambient temperature.

The current electric vehicles (EVs) face many challenges like limited charge capacity, low miles/charge, and long charging times. Herein, these issues are addressed by developing a dual-function supercapacitor-based energy-storing carbon fiber reinforced polymer (e-CFRP) that can store electrical energy and function as the structural component for the EV's body shell. This is achieved by developing a unique design, vertically aligned graphene sheets attached to carbon fiber electrodes on which different metal oxides are deposited to obtain high-energy density electrodes. A high-strength multilayer e-CFRP assembly is fabricated using an alternate layer patterning configuration of epoxy and polyacrylamide gel electrolyte. The e-CFRP so developed delivers a high areal energy density of 0.31 mWh cm(-2) at 0.3 mm thickness and a high tensile strength of 518 MPa, bending strength of 477 MPa, and impact strength of 2666 J m(-1). To show its application in EVs, a toy car's body panel is fabricated with e-CFRP and the toy car is able to operate using the energy stored in its frame. Moreover, when integrated with a solar cell, this composite powers an Internet of Things device, showing its feasibility in communication satellites.

Organic electrochemical transistors (OECTs) have been hailed as highly sensitive biomolecular sensors among organic electronic devices due to their superior stability in an aqueous environment and high transconductance. At the same time, plasmon based sensors are known to provide high sensitivity for biosensing due to the highly localized plasmonic field. Here we report a plasmonic OECT (POET) device that synchronizes the advantages of OECTs and plasmonic sensors on a single platform. The platform is fabricated by a simple, cost-effective, and high-throughput nanoimprinting process, which allows plasmonic resonance peak tuning to a given visible wavelength of interest for versatile biosensing. With glucose sensing as proof, a five-times sensitivity enhancement is obtained for POET compared to a regular (non-plasmonic) OECT. Thus, the POET paves the way to a new paradigm of optoelectronic sensors that combines the inherent high sensitivity of OECTs and localized plasmonic field to sense a vast realm of biomolecules.

As electric vehicles (EVs) are evolving, innovative technologies like “energized composite” that can store energy in the car's body helps extend its range per charge. The composite's unique ability to function as both structural body panel and charge storage medium stems from its unique pattern design between “electrochemical areas (EcA)” and “epoxy area (EpA)”. Herein, a design optimization study is presented to obtain a balanced ratio between EcA versus EpA to maximize the charge storage ability of the composite while maintaining a decent tensile and bending strength. Simulations using ANSYS software and experimental confirmation using universal testing machines and electrochemical analyzers are used to derive optimum ratios between EcA and EpA. Uniaxial tension test and 3‐point bend test have been performed to optimize the tensile and bend strengths, whereas cyclic voltammetry, galvanic charge–discharge, and electrochemical impedance spectroscopy are used to determine the electrochemical performance of various design configurations by modulating the ratios of EcA versus EpA. Overall, the highest achieved energy storage per lamina is 2531 mWh m −2 for a maximum of 81.6% EcA with a tensile strength of 417.73 MPa and bending strength of 263.13 MPa. This study is highly beneficial for EVs and aerospace applications.

In article number 2000535, Kaitlyn E. Crawford, Jayan Thomas, and co-workers grow perovskite quantum dots (PQDs) on multi-wall carbon nanotubes (MWCNTs) to fabricate two-terminal optoelectronic synapses. The photonic memory effect is demonstrated using this artificial synapse. Since the PQDs are grown on each MWCNT, this new hybrid material is beneficial for future nanoscale neuromorphic computing and sensing devices.

The long cycle life of the energy storage devices depends on the structural and chemical stability of the electrode material used. Developing energy storage devices with a longer cycle life helps in avoiding frequent replacement of the devices, cuts down cost of replacing and recycling dead batteries and supercapacitors. This makes the cycle life to be a vital parameter to focus on developing efficient energy storage devices. Supercapacitors, an electrochemical energy storage device has important characteristics of high-power density, fast charging, and long cycle life. Most of the electrode materials used in supercapacitor undergo surface, structural and chemical changes during cycling which leads to change in the capacitance retained. A thorough qualitative analysis is important to investigate the reason behind these changes occurring at the electrode. We employed a surface analysis tool such as Kelvin probe force microscopy (KPFM) to probe the reason behind capacitance change of a two-dimensional (2D) electrode during cycling. We investigated the cycling performance of 2D electrode material, tungsten disulfide (WS2) via KPFM and Raman studies. The results obtained via KPFM revealed that during cycling, WS2 layers develop strain due to intercalation/deintercalation of electrolyte ions. This leads to increase in the available electrochemical active sites leading to increased capacitance. The charge contribution studies revealed that the strain in the WS2 layers led to increased redox charge storage behavior of the electrode during cycling. Such qualitative studies will benefit in understanding the reason behind the structural changes during cycling and will help in developing highly efficient and long-lasting energy storage devices. This study can be further extended to other electrode materials employed in supercapacitor as well as batteries.

Currently, a major constraint in employing supercapacitors as a solitary energy storage device in applications like electric vehicles is their low energy density. In aqueous asymmetric supercapacitors, the energy density is limited by the voltage window, which is governed by the electrode's work functions. Here, the preinsertion of different metal cations such as Li+, Na+, and K+ ions into manganese dioxide (MnO2) to tune the electrode's work function is demonstrated. Sodium-doped MnO2 (NaMnO2) exhibited a lower work function than Li+ and K+ preinserted electrodes. This lowering of the work function leads to a higher voltage window. The work function tuned NaMnO2 is coupled with a high-work-function negative electrode material, molybdenum oxide (MnO2), to fabricate a 2.5 V aqueous asymmetric supercapacitor. The supercapacitor delivered a maximum energy density of 78 Wh kg(-1), a power density of 4.6 kW kg(-1), and capacitance retention of 98.6% after 5000 cycles. This work brings new insights into the engineering of electrode's work function for developing high-voltage and high-energy supercapacitors.