Understanding charge-carrier recombination in metal halide perovskites is essential for accurately identifying the factors limiting solar cell efficiency, yet it remains challenging due to the interplay of multiple competing processes. Here, we combine time-resolved photoluminescence and excitation dependent photoluminescence quantum yield measurements over a wide range of fluences and repetition rates to investigate recombination dynamics in triple-cation perovskite thin films. By jointly analyzing these multidimensional datasets, we develop a unified model that quantitatively reproduces both photoluminescence decays and absolute quantum yields across all excitation conditions. Our results reveal the coexistence of deep and shallow traps, as well as a second-order nonradiative recombination pathway attributed to Auger-assisted trapping. Importantly, this mechanism dominates under one-sun illumination, making it a critical limiting factor for photovoltaic performance. These findings provide a comprehensive framework for understanding recombination in perovskites and highlight the importance of higher-order defect-mediated processes in determining their efficiency.

In the last few years, carrier-selective contacts (CSCs) have emerged as a new concept to reduce the fabrication complexities and losses associated with conventional doped p–n junction high-efficiency solar cells. III–V direct bandgap compound semiconductor-based ultrathin heterojunction solar cells have recently attracted significant attention due to efficient charge carrier collection, increased defect tolerance, photon recycling, reduced material usage, lower manufacturing costs, and flexibility. Here, we present a high-efficiency photovoltaic device utilizing a 280 nm thin InP absorber layer, incorporating both electron- and hole-selective contact layers to form a double-heterojunction structure. The device operation is numerically simulated using FDTD and CHARGE modules of the Lumerical software package. This structure reduces the epitaxial thickness, minimizes the cost, while achieving an open-circuit voltage (VOC) of 1.056 V and power conversion efficiency (PCE) of 28.54

InAs/GaAs is a promising material since its properties can be explored under confined conditions in the form of a quantum dot (QD). A QD is generally grown with a thin layer, known as the wetting layer (WL), to reduce its strain and achieve the desired fundamental properties and stability. However, marginal error in the WL can change the fundamental properties of the QD from its targeted value. This study discusses the negative impact in the energy states of InAs/GaAs QDs under possible variation in the WL thickness, along with radius, height and interface barrier potential variations. The investigation was conducted on a conical-shaped QD (CoQD), spherical-shaped QD and cylindrical-shaped QD using ARPCAK solver in COMSOL tool. The study reveals that the WL restricts rapid change in the properties of all three QDs with change in their sizes and barrier potential. The discussed QDs have optimum radius for a given height and vice versa for the minimum transition energy (TE) in the presence of the WL. Furthermore, these mini energies have a significant dependence on the WL thickness. The TE of the QDs is calculated by solving the single-band effective mass Schr & ouml;dinger equation in a 2D axisymmetric geometry, where the radii of the QDs are set between 1 and 10 nm, the height between 0.5 and 5 nm, and the WL thickness is considered between 0.5 and 5 nm. An energy minimum around 2 nm is exhibited for the investigated radius-height combinations. Moreover, the energy increases significantly with the change in the WL thickness, similar to 0.1 eV nm -1 for CoQD, from the values corresponding to the minimum energy. Our investigations help in understanding the importance of controlling the WL thickness to maintain the properties of the QD in the desired range.

Amidst the advancements in nanotechnology, this paper explores the enhancement of solar cell (SC) efficiencies through the innovative use of nanowire (NW) architectures composed of III-V semiconductor materials such as Gallium Arsenide (GaAs). These NWs are renowned for their superior optical and electrical properties, including high absorption coefficients and enhanced charge carrier mobility, which collectively improve power conversion efficiencies (PCE). Additionally, their structural design significantly reduces material usage, offering a sustainable alternative to traditional planar SCs. This research primarily investigates the integration of unique anti-reflective conical nanostructures and aluminum (Al) metal layers within GaAs NW-SCs to enhance their performance. Utilizing the finite difference time domain (FDTD) method and charge solver module in the Lumerical software package, we examined various conical configurations at the apex and assessed the impact of an Al back reflector at the base. Our results revealed that optimizing the effect of three different anti-reflective structures, specifically the truncated cone, simple cone, and parabolic cone coupled with adjustments in the Al layer’s thickness, maximizes light absorption due to Surface Plasmon Resonance (SPR). Among the nanostructures, the truncated cone structure was selected for its superior performance of overall efficiency enhancement. The role of Al in extending the operational spectrum by shifting plasmonic resonances toward the ultraviolet enables it to outperform other metals in enhancing light trapping and reducing surface reflection losses. The strategic placement of these nanostructures within the cell architecture is crucial for tapping into significant efficiency gains through advanced light management techniques. The enhancements led to a 20.36

The valence band structure and optical transitions of holes are investigated for elongated InGaAs/GaAs quantum dot (QD). We use the 4 x 4 Luttinger Hamiltonian under effective mass approximation for the estimation of the valence band structure. The energy eigenvalues and corresponding eigenvectors have been calculated by numerical diagonalization of Hamiltonian for lens-shaped QD using the harmonic oscillator basis function without considering the strain effect. We analyzed the impact of the size and composition of the QD on valence band structure and the transition probability of holes from ground state to excited states. The analysis reveals that the hole energy states form the energy band of heavy-hole (hh) and light-hole (lh) states. The band mixing of hh and lh energy states is decreasing with an increase in the lateral dimension (L-D) of the QD which is indicated by the increase in the hh-lh band offset (B-off) parameter. The hh and lh states show strong intermixing for the small values of indium (In) concentration less than 0.23 and for the Lo less than 10 nm for which the B(off )parameter is found to be less than 25.22 meV. The widths of hh and lh bands are found to decrease with an increase in L-D, and it is increasing with In concentration of the QD. The transitions from hh to hh states are polarization-sensitive, but transitions from hh to lh states are insensitive to the polarization state of the incident photon. The square optical matrix elements are decreasing with L(D )and increasing with In concentration.

This study investigates the effect of particle concentration on tuneable magneto-optical transmittance and optically induced refractive index coefficients in Fe3O4-based nanomagnetic fluid (NMF) at room temperature. A static magneto-optical experimental setup was devised to investigate the magneto-optical effects arising from variations in particle concentration and dipolar interactions, under varying magnetic fields. In this work, Fe3O4-based nanomagnetic fluid was synthesized using a chemical co-precipitation method. The structural, morphological, and magnetic properties of the fluid were investigated using sophisticated characterization techniques including x-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and vibrating-sample magnetometry (VSM). Our investigation focused on the tunability of magneto-optical transmittance as a function of the varying magnetic field at different particle concentrations. Further, we observed variations in diffraction fringes in the nanomagnetic fluid, correlating with particle concentration, by passing a high-power laser through the diluted fluid system. Light-matter interaction in the presence of a varying magnetic field induces optical anisotropy in the fluid, whereas dipole-moment interaction and magnetic particle alignment in the presence of a magnetic field are the main supporting phenomenon of magneto-optical tunability in our experiment. Experimental modulation of the transmittance profile and field-induced refractive index coefficients in NMF, elucidated through fringe diffraction, has potential for applications such as tuneable magneto-optical devices, optical filters, and optical limiters.

Tunnel field-effect transistors (TFETs) are a promising alternative to conventional MOSFETs for low-power applications due to their ability to achieve a sub-60 mV/dec subthreshold swing. However, a detailed comparative analysis of different tunneling mechanisms, specifically line and point tunneling, remains a critical gap in the literature. This study addresses this by presenting a comprehensive comparison of Ge/Si heterojunction TFETs, with separate structures optimized for each tunneling mechanism (Ge source, Si channel/drain). Our simulations reveal that the line tunneling device (D2) exhibits superior performance compared to the point tunneling device (D1), demonstrating a higher on-current (3×10−5 A), lower off-current (5×10−18 A), a higher current ratio (6×1012), a lower subthreshold slope (18 mV/dec), and a lower threshold voltage (0.22 V). These performance enhancements are attributed to a larger tunneling space and a stronger electric field in the line tunneling configuration. Furthermore, the D2 device shows reduced ambipolar conduction and improved temperature stability. These findings highlight the significant advantages of line tunneling and provide a clear pathway for designing high-performance TFETs.

This work presents a comprehensive investigation of symmetric underlap double-gate (DG) graphene nanoribbon tunnel field-effect transistors (GNR TFETs), emphasizing their suitability for low-power and analog/RF applications. The proposed architecture introduces symmetric underlap engineering to improve device characteristics. The influence of underlap length variation is examined in terms of ON/OFF current ratio (I ON /I OFF ), drain-induced barrier lowering (DIBL), subthreshold swing (SS), transconductance (g m ), and transistor efficiency (g m /I D ). Using atomistic simulations within the Non-Equilibrium Green’s Function (NEGF) framework in NanoTCAD ViDES, results show that symmetric underlap design effectively suppresses ambipolar conduction, reduces OFF-state leakage, and improves analog performance metrics such as intrinsic gain and transistor efficiency. However, these benefits are achieved at the expense of RF figures-of-merit, including cutoff frequency (f T ), gain–frequency product (GFP), and transit–frequency product (TFP), which degrade with increasing underlap length. These findings highlight the inherent trade-off introduced by underlap engineering, offering valuable design guidelines for tailoring GNR TFETs toward either ultra-low-power analog applications or RF integrated circuits (RFICs).

A comparative study of the crystal structures and electrochemical characteristics of bulk and nanoscale La1-xPrxCoO3 (x = 0, 0.3 and 0.6) perovskites is made using synchrotron x-ray diffraction, cyclic voltammetry, and galvanostatic charge/discharge methods. It is shown that the sol-gel synthesized nano structures and bulk LaCoO3 exhibit different crystal structures, viz., rhombohedral [a = b = 5.4401 angstrom, c = 13.134 angstrom (on hexagonal axes), Z = 6, R (3) over bar c] and monoclinic [a(m) = 5.3865 angstrom, b(m) = 5.4482 angstrom, c(m) = 7.6365 angstrom, beta(m) = 89.010 degrees, Z = 4, I2/a], respectively. The evidence for CoO6 octahedra distortion in bulk LaCoO3 is also gathered from the three distinct Raman active modes at 518, 646, and 688 cm(-1) emerging due to the Jahn-Teller effect, which, in-turn, reduces the crystal symmetry for achieving structure stabilization. This amounts to changes in Co-O bond lengths and Co-O-Co bond angles with promotion of t(2g) electron to e(g) level simultaneously for Co3+(3d(6)) to attain an intermediate spin state (S = 1) or higher. However, Pr-insertion induces phase transition to orthorhombic in both but with space group Pnma in nanostructures and equivalent Pbnm in bulk. The substitution effect on the specific capacitance (C) is opposite in nature, i.e., while 'C' decreases from 149 to 12 F/g in nano structures, it increases from 0.4 to 4 F/g in bulk with increase in Pr-content from x=0 to 0.6. A galvanostatic charge-discharge test of pristine nano LaCoO3 performed at a constant scan rate of 50 mVs(-1) reveals electrode electrochemical stability by retaining 96 % of specific capacitance similar to 82.5 F/g for 2000 cycles at least. The variation in the crystal structure and bond length and/or angle plays a key role in controlling the electrochemical performance of Pr-substituted LaCoO3 perovskites.

As transistors are scaled down to below 5 nm, it becomes very difficult to form sharp and well-controlled source and drain junctions. Junctionless (JL) transistors avoid the use of source and drain junctions, making the fabrication process easier. In this work, we investigate the performance of ultra-scaled double-gate (DG) carbon nanotube field-effect transistors (CNTFETs) with a JL configuration using atomistic quantum transport simulations based on the non-equilibrium Green’s function (NEGF) formalism. A novel doping scheme is proposed, featuring equivalent n-type doping under the gate region to maintain junctionless behavior while enhancing carrier injection. This strategy effectively addresses scaling-induced limitations and yields notable improvements in key device metrics, including enhanced ON-current (ION), improved current ON/OFF ratio (ION/ IOFF), higher transistor efficiency (gm/ID), and an increased quality factor (Q = gm/SS). The proposed approach demonstrates strong potential for next-generation sub-5 nm FET technologies.

Regenerated cellulose (RC) was prepared from pineapple crown waste fiber (PCWF) with a yield of about 45 %. The RC was blended with hardwood pulp (HP) to improve the mechanical properties of the paper. The composite paper with improved tensile index from 16.87 +/- 0.75 NN mm/g to 28.98 +/- 1.2 NN mm/g and burst index from 0.974 +/- 0 .083 kkPaPa mm22/g to 1.827 +/- 0 .153 kkPaPa mm22/g was developed by blending 20 % RC with 80 % HP. It was calculated that the production of one tonne of RC generates about 130 m3 of wastewater and it can be recycled after treatment with electrocoagulation technique. After wastewater treatment, chemical oxygen demand (COD) was reduced 84.8 %, total suspended solid (TSS) by 95.6 %, total dissolved solids (TDS) by 30.4 %, and biochemical oxygen demand (BOD) by 95.8 %. Importantly, the recycling behavior by reusing/recycling the treated wastewater for the regeneration process was investigated and a yield of about 42 % of the RC was observed.

In India, where there is a scarcity of reliable electrical power, combining renewable energy sources with traditional ones offers a practical alternative for electrifying remote areas. The paper aims to analyze solar PV performance by evaluating performance indices that justify use of solar PV panels in a remote location of West Bengal. The annual mean performance indices such as performance ratio (PR), capacity factor (CF), array yield, final yield, reference yield array capture, and system losses have been evaluated. The variation in the cell temperature of PV concerning the ambient temperature of the region has also been presented. The results show the yearly average PR and CF of the solar PV array are obtained as 75.31 and 14.83

Excessive deforestation caused by the demand for wood as a primary raw material in papermaking has a direct and detrimental impact on the environment. Therefore, it is crucial to explore alternative natural resources for paper production. Global surveys indicate that the juice manufacturing industry generates a substantial amount of waste, posing significant challenges for waste management. A recent investigation has revealed that pineapple (Ananas comosus) crown waste (PCW) could serve as a viable source of fibrous raw material. Findings demonstrated that PCW contains approximately 74

The utilization of waste generated by natural resources is a crucial problem nowadays. The current study describes the utilization of pineapple (Ananas comosus) crown residue husk (PCRh) as a strength additive for low-density polyethylene (LDPE) and ethylene propylene rubber (EPR) composites. The blend composites with 30% husk, 10 wt % EPR, and 60% LDPE content showed much better mechanical properties, such as tensile strength and flexural properties, than pristine LDPE and its binary composite with 10 wt % EPR. The high tensile strength (∼19.28 MPa) and tensile modulus (522.97 MPa) were obtained for the composite consisting of 30 wt % PCRh in the basic polymer matrix. Similarly, the highest flexural strength (∼18.09 MPa) and modulus (∼790.29 MPa) were recorded for the same composition. The incorporation of PCRh with LDPE and EPR was further characterized by attenuated total reflection-Fourier transform infrared, differential scanning calorimetry, field emission scanning electron microscopy, dynamic mechanical analysis, and a universal testing machine to evaluate its impact on various properties.

This study investigates the effect of particle concentration on tuneable magneto-optical transmittance and optically induced refractive index coefficients in Fe3O4-based nanomagnetic fluid (NMF) at room temperature. A static magneto-optical experimental setup was devised to investigate the magneto-optical effects arising from variations in particle concentration and dipolar interactions, under varying magnetic fields. In this work, Fe3O4-based nanomagnetic fluid was synthesized using a chemical co-precipitation method. The structural, morphological, and magnetic properties of the fluid were investigated using sophisticated characterization techniques including x-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and vibrating-sample magnetometry (VSM). Our investigation focused on the tunability of magneto-optical transmittance as a function of the varying magnetic field at different particle concentrations. Further, we observed variations in diffraction fringes in the nanomagnetic fluid, correlating with particle concentration, by passing a high-power laser through the diluted fluid system. Light–matter interaction in the presence of a varying magnetic field induces optical anisotropy in the fluid, whereas dipole–moment interaction and magnetic particle alignment in the presence of a magnetic field are the main supporting phenomenon of magneto-optical tunability in our experiment. Experimental modulation of the transmittance profile and field-induced refractive index coefficients in NMF, elucidated through fringe diffraction, has potential for applications such as tuneable magneto-optical devices, optical filters, and optical limiters.

In practice, reducing reactive power to enhance system efficiency is a common objective. While this approach is generally beneficial, it can pose challenges in electrical systems that are purely resistive or capacitive. AC power systems involve the supply or consumption of two types of power: real power, which executes convenient effort, and reactive power, which provisions voltage points critical for system reliability. The management of reactive power significantly influences the security of power systems by impacting voltage stability across the network. The demand for power has surged rapidly while our generation resources remain limited. Consequently, transmission lines are becoming heavily loaded, leading to stability issues, voltage drops, and reactive power challenges. This paper explores the necessity of reactive power and various compensation techniques essential for any power system. It focuses particularly on FACTS devices like SSSC, TCR, TCSC, STATCOM, UPFC and DPFC.

This work investigates analog/RF performance characteristics of graphene nanoribbon (GNR) tunnel field-effect transistors (TFETs) featuring source-end pocket engineering. Utilizing self-consistent atomistic simulations and the nonequilibrium Green's function (NEGF) framework, this novel research work focuses on optimizing pocket length for GNR TFETs by examining the ON-current ( I- on ) to OFF-current ( I- off ) ratio I on / I-off , providing insights into digital performance parameters. The optimized pocket length identified for the observed device is 5 nm. Furthermore, to enhance performance in various analog and RF applications, the impact of pocket engineering on analog/RF figures of merit (FoM) are analyzed. Transconductance ( g( m )), transconductance generation factor (TGF), output conductance ( g (ds )), intrinsic gain ( g( m)r(0) ), gate capacitance ( C- G ), cut-off frequency ( f( T )), and transconductance frequency product (TFP) are examined. The results indicate that GNR TFETs with pocket engineering perform better than conventional GNR TFETs. The improvements and the lags have been discussed in detail in this report.

Gallium arsenide (GaAs) nanowire (NW) solar cells (SCs) have piqued the interest of researchers because they exhibit superior light-harvesting and anti-reflection properties along with reduced material consumption compared to their planar counterparts. However, the high surface-to-volume ratio associated with these NWs degrades their performance in practical applications. Light trapping is considered one of the most crucial parameters for producing low-cost high-efficiency NW-SCs. Thus, numerous light-trapping strategies have been explored, among which surface plasmon resonance (SPR) based optical absorption enhancement using metal nanoparticles (NPs) has emerged as a potential method. The role of plasmonic aluminum (Al) NPs in the efficiency enhancement of GaAs NW SC has not yet been explored. Therefore, in this study, a vertically aligned GaAs NW SC structure incorporated with Al NPs has been investigated using the finite-difference time-domain (FDTD) method. The sidewalls of GaAs NWs are embellished with uniformly arranged Al NPs with diameters ranging from 30 to 60 nm. The excitation of localized surface plasmon resonance in metal NPs results in significant light absorption enhancement at the GaAs near-band of the proposed structure. The results demonstrate that even with a low aspect ratio (D/P) of 0.3, optimizing the geometrical parameters of the NPs results in a 41.96 % increase in power conversion efficiency (PCE) and a 45 % increase in absorption efficiency at 800 nm for the proposed structure when compared to the bare structure. Hence, our suggested structure which utilizes the light-trapping mechanism of Al NPs proves to be a cost-effective and promising material combination for high-efficiency nanoscale SCs.