The strong visible photoluminescence (PL) in surface-oxidized nanostructured silicon emerges from the interplay between intrinsic Bloch states and oxide-related interfacial defects, making it difficult to isolate their role. Temperature-dependent (5-350 K) PL measurements on nanostructured silicon with varying crystallite sizes manifest three distinct decay mechanisms involving band-to-band, band-to-trap and trap-to-trap transitions to multiple emission bands appearing in the convoluted broad PL spectrum. At lower temperatures (less than or similar to 225 K), PL peak energy associated with the quantum-confined Bloch states exhibits a nearly linear blue shift, governed by a strong inverse power law dependence of the temperature coefficient on the effective crystallite size, while this trend reverses at higher temperatures. Conversely, the defect-related peak energies increase monotonically at a nearly constant rate throughout the experimental temperature range. A general analytical model for finite systems with a separable pseudo-potential effectively estimates the contributions from different decay channels to the PL emission. Theoretical results align well with the experimentally obtained values of the power-law exponents, offering a novel way to distinguish between the radiative recombination channels involving quantumconfined Bloch states and interfacial defects/trap states in nanostructured silicon.
This article investigates the memory effects in a two-dimensional thermoelastic problem for a fiber-reinforced anisotropic porous medium within the Moore-Gibson-Thompson (MGT) framework, subjected to thermal-shock-induced transient boundary conditions. The proposed model employs the memory-dependent derivative (MDD) to capture thermo-mechanical memory and considers the role of voids. This approach provides a more accurate and physically consistent description of the coupled thermal and mechanical behavior of porous materials. The governing equations are solved using the eigenvalue method after applying combined Laplace and Fourier transforms, with numerical inversion performed through the Stehfest and Gaussian quadrature techniques. Graphical results highlight how different kernels, models, and boundary conditions vary with and without the presence of voids. Furthermore, this study also presents three-dimensional visualizations of displacement, volume fraction, temperature and stress fields.
The fabrication of sputtered indium tin oxide (ITO) nanorod arrays offers a promising and economical approach to improving light management in photovoltaic devices. In this study, we introduce a novel light-trapping approach using a sputtered ITO nanorod array as a substitute for traditional surface texturing. We successfully fabricated a hydrogenated amorphous silicon (a-Si:H) p-i-n solar cell on the ITO nanorod substrate and compared its performance to a standard reference device. The ITO nanorods, grown at 320 °C, exhibited excellent optical properties, with a diffused-to-total transmitted light ratio exceeding 50
This work explores a new cellular automaton model, where two rules, say f and g are applied with some probability to each cell temporarily. Rule f acts as default rule of the model, whereas rule g is treated as a noise rule and applied with probability τ . This class of cellular automata is called Temporally Stochastic Cellular Automata (TSCAs). The dynamical behaviour of these automata is studied to identify the list of convergent TSCAs. This work identifies the similarities between TSCAs and Markov chains, and shows that the dynamics of the TSCAs are Markovian. We utilise absorbing Markov chain as a tool to study the convergence of TSCAs. Finally, we study the theoretical aspects behind the convergence of TSCAs to validate the experimental outcomes of dynamical studies.
This study presents a mathematical framework to examine the thermoelastic response of an unbounded isotropic medium with a cylindrical cavity exposed to a continuous line heat source. The analysis employs the dual-phase-lag (DPL) heat conduction model under traction-free and ramp-type thermal conditions within generalized thermoelasticity. Building upon earlier eigenvalue-based formulations in Cartesian coordinates, this work extends the analytical methodology to cylindrical geometry, enabling a more realistic representation of thermal and elastic interactions induced by line heat sources. The governing equations are transformed into the Laplace domain and reduced to a vector–matrix system of coupled differential equations. Analytical expressions for field variables are obtained in the transformed domain and numerically inverted into the time domain using Stehfest’s algorithm implemented in MATLAB. The results graphically demonstrate how ramp-type heat, phase-lag, and time parameters influence the propagation of field variables, emphasizing the analytical significance of the adopted methodology. The novelty of this study lies in the combined analytical and numerical formulation of a DPL-based thermoelastic model for cylindrical geometry under ramp-type heating, offering a realistic representation of finite-speed thermal and elastic wave propagation pertinent to advanced engineering and biomedical systems.
