Rajesh Kumar

“Microbatteries” are known to be the key to device miniaturization, but the practicality associated with one such domain of SnS thin films in Na-ion microbatteries (Na-μBs) is limited by slow Na+ kinetics and cycling-induced pulverization. These issues are strongly affected by microstructure, crystallinity, and interface quality, which can be tuned through growth temperature; however, their correlation with electrochemical performance remains unclear. Herein, SnS thin films with a thickness of 86.76 ± 4 nm were prepared via hydrothermal-assisted thermal evaporation at varying growth substrate temperatures. The optimal film growth occurs at 200 °C under sulfur-deficient conditions, yielding a high areal discharge capacity of 55 μAh/cm2 at a high current density of 200 μA/cm2 and remarkable retention of 88.6% over 150 cycles. The CV and DFT analyses reveal the capacitive–diffusive kinetics and charge localization around sulfur in SnS, facilitating Na–S bonds in conversion alloying reactions. Furthermore, demonstrations of powering LEDs highlight the practical applicability of SnS thin films as anodes in Na-μBs.

The fast growth of semiconductor and low dimensional materials has created a necessity for robust characterization approaches to study their structural and electrical properties. The most popular tool for this goal is the Raman spectroscopy however the asymmetric shape of Raman lines is often observed due to the phonon confinement and the Fano interference which makes their interpretation difficult. Here, a user‐friendly web‐based computational platform is proposed that combines the phonon confinement, Fano, and combination Fano‐confinement models for automated Raman line‐shape analysis. The software allows users to submit Raman spectra and get quantitative analysis, model comparison, and parameter extraction with a single click. The software democratizes advanced Raman analysis to non‐expert users who do not have programming or theoretical experience. The framework was tested on Raman spectra with dominating confinement, dominant Fano interaction, their coexistence and on published silicon nanocrystal data, providing crystallite sizes compatible with reported studies. Future versions will incorporate a comprehensive multi‐material database for intelligent material identification and rapid spectral interpretation for next‐generation Raman spectroscopy.

NDR phenomenon can be influenced by electrode asymmetry, coulomb blockade, molecule–electrode, molecular conformational changes, redox reactions and charging effects, advancing the development of next generation molecular devices.

Angle resolved polarization Raman spectroscopy reveals the anisotropic quantum interference between discrete acoustic phonons and excitonic continuum states in CVD-grown multi-layered WS ₂ nanoflakes.

The unique capability of electrochromic (EC) materials (ECMs) to reversibly modulate optical properties through electrical stimulation has positioned them at the forefront of adaptive and energy-efficient technologies. However, the widespread deployment of conventional EC systems (like inorganic, organic, organometallic, etc.) remains constrained by fundamental challenges, including limited electrical conductivity, insufficient cycling durability, and restricted functionality. This in turn limits the consequent devices’ performance. In response to these challenges, composite engineering has emerged as a transformative approach for tailoring EC performance through the synergistic integration of diverse material components. Through deliberate design of compositions, interfaces, and hierarchical structures, composite ECMs improve charge-transfer kinetics, optical contrast, and structural robustness. Recent advances in composite-based ECMs and devices are highlighted here with a focus on the design strategies and structure-performance relationships that underpin their improved functionality. Key developments in conducting polymer–metal-oxide composites, MXene-based heterostructures, quantum dot-modified systems, and plasmonic architectures capable of regulating both visible and infrared radiation are critically examined. The emerging convergence of electrochromism with energy storage, thermal regulation, and adaptive camouflage is further described as a promising route toward multifunctional intelligent systems. Finally, critical challenges related to interfacial stability, scalable manufacturing, sustainability, and performance evaluation are discussed, alongside future directions for next-generation EC technologies. Design insights for developing high-performance composite ECMs have been discussed that meet the growing demands of energy-efficient and adaptive optoelectronic applications.

Metal–semiconductor heterostructures provide a versatile platform for tuning light–matter interactions at the nanoscale. At the heterostructure interface, excitonic resonances in semiconductors interact with plasmonic fields of metallic nanostructures giving rise to exciton-plasmon coupling (EPC). This coupling controls energy transfer, charge separation and carrier dynamics across the interface. The strength of EPC ultimately dictates the macroscopic optoelectronic response of the hybrid systems. The coupling strength is sensitive to several interdependent parameters, such as electromagnetic field confinement, oscillator strength, nanostructure geometry, and dissipative interactions, giving rise to diverse interaction regimes, from strong to weak, which show distinct physical characteristics. Despite extensive experimental and theoretical progress, a comprehensive understanding of the emergence and evolution of EPC remains elusive, as coherent hybridization, energy/charge transfer and dissipative processes often coexist within the hybrid system. The interplay between these processes manifests in complex spectral signatures like anticrossing, linewidth modification and intensity enhancement, often obscuring the underlying coupling mechanism. In this review, we present a unified perspective on EPC, treating strong, intermediate, and weak coupling within a continuous conceptual framework, ranging from hybrid eigenstates to perturbative modifications of excitonic and plasmonic resonances. This framework provides a basis for linking these ambiguous spectral signatures across coupling regimes to their underlying microscopic processes. The review further links the EPC mechanisms to device performance in functional and scalable technologies like biosensing, photodetection, photovoltaics, and quantum systems. Finally, we evaluate the fundamental and architectural bottlenecks that hinder translation beyond proof-of-concept demonstrations, thus offering a critical design roadmap for the rational design of scalable EPC-based systems. We argue that addressing these constraints requires a shift from demonstration-driven studies to custom designs that prioritize loss engineering, interface control, mechanism-resolved characterization, and scalable architectures treated as primary design parameters.

Plastic crystals (PCs) have recently gained renewed interest due to their potential applications in emerging sustainable technologies. PCs, typically characterized by high entropic reversible solid‐to‐solid phase transitions, facilitate effective energy conversion and can be used as barocaloric materials in refrigeration technologies. However, the intricate relationship between their structure and physical properties associated with the solid‐to‐solid phase transformations remains underexplored. Moreover, studies focusing on phase transition temperature, hysteresis loop, and mechanical properties are scarce in the literature. Here, we show an ordered crystalline (OC, Phase III) 2‐adamantanol (2‐Aol) with two extremely low hysteretic reversible solid‐to‐solid phase transitions, one at 50°C, to a semi‐ordered plastic crystal (SOPC) phase (Phase II) and the other at 115.6°C, to a fully re‐orientational disordered phase (RD, Phase I). Furthermore, the mechanical properties, obtained using a variable temperature nanoindentation technique, show a significant drop in elastic modulus and hardness upon the OC‐to‐SOPC (III→II) phase transition, confirming the influence of the reorientational motions of molecules in the high‐temperature phase.

Energy demand and sustainable development goals are key terms around which materials for future technology are being designed. Here, a core‐shell type zinc cobalt sulfide/polyindole (ZCS@PI) composite in a honeycomb structure has been engineered through a two‐step electrodeposition process, enhancing charge transfer for fabricating a prototype quasi‐solid supercapacitor capable of powering electronic appliances. The ZCS@PI electrode could achieve a specific capacitance of 4700 Fg ⁻¹ , with 96% of the charge storage attributed to diffusion‐controlled processes. Its high capacitance is attributed to the presence of more electroactive sites, as confirmed by molecular electrostatic potential plots for ZCS and PI. Ex situ Raman spectroelectrochemistry was used to establish the charging/discharging mechanism. Thus, the fabricated prototype device maintained its full energy capacity, exhibiting high capacitance, energy, and power densities, and retained 82% capacitance after 3000 cycles. The device could power LEDs and DC motors, making the design worth on‐field use.