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Metal halide perovskites have brought about a disruptive shift in the field of third-generation photovoltaics. Their potential as remarkably efficient solar cell absorbers was first demonstrated in the beginning of the 2010s. However, right from their inception, persistent challenges have impeded the smooth adoption of this technology in the industry. These challenges encompass issues such as the lack of reproducibility in fabrication, limited mid- and long-term stability, and concerns over toxicity. Despite achieving record efficiencies that have outperformed even well-established technologies, such as polycrystalline silicon, these hurdles have hindered the seamless transition of this technology into industrial applications. In this Perspective, we discuss which of these challenges are rooted in the unique dual nature of metal halide perovskites, which simultaneously function as electronic and ionic semiconductors. This duality results in the intermingling of processes occurring at vastly different timescales, still complicating both their comprehensive investigation and the development of robust and dependable devices. Our discussion here undertakes a critical analysis of the field, addressing the current status of knowledge for devices based on halide perovskites in view of electronic and ionic conduction, the underlying models, and the challenges encountered when these devices are optoelectronically characterized. We place a distinct emphasis on the positive contributions that this area of research has not only made to the advancement of photovoltaics but also to the broader progress of solid-state physics and photoelectrochemistry. [ABSTRACT FROM AUTHOR]

Engineering microstructural defects, like grain boundaries, offers superior control over transport properties in energy materials. However, technological advancement requires establishing microstructure‐property relations at the micron or finer scales, where most of these defects operate. Here, the first experimental evidence of thermal resistance for individual silicon grain boundaries, estimated with a Gibbs excess approach, is provided. Coincident site lattice boundaries exhibit uniform excess thermal resistance along the same boundary, but notable variations from one boundary to another. Boundaries associated with low interface energy generally exhibit lower resistances, aligning with theoretical expectations and previous simulations, but several exceptions are observed. Transmission electron microscopy reveals that factors like interface roughness and presence of nanotwinning can significantly alter the observed resistance, which ranges from ∼0 to up to ∼2.3 m2K/GW. In stark contrast, significantly larger and less uniform values ‐ from 5 to 30 m2K/GW ‐ are found for high‐angle boundaries in spark‐plasma‐sintered polycrystalline silicon. Further, finite element analysis suggests that boundary planes that strongly deviate from the sample vertical (beyond ∼45°) can show up to 3‐times larger excess resistance. Direct correlations of properties with individual defects enable the design of materials with superior thermal performance for applications in energy harvesting and heat management. [ABSTRACT FROM AUTHOR]

Tunnel oxide passivated contact (TOPCon) silicon solar cells are rising as a competitive photovoltaic technology, seamlessly blending high efficiency with cost-effectiveness and mass production capabilities. However, the numerous defects from the fragile silicon oxide/c-Si interface and the low field-effect passivation due to the inadequate boron in-diffusion in p-type polycrystalline silicon (poly-Si) passivated contact reduce their open-circuit voltages (VOCs), impeding their widespread application in the promising perovskite/silicon tandem solar cells (TSCs) that hold a potential to break 30% module efficiency. To address this, we have developed a highly passivated p-type TOPCon structure by optimizing the oxidation conditions, boron in-diffusion, and aluminium oxide hydrogenation, thus pronouncedly improving the implied VOC (iVOC) of symmetric samples with p-type TOPCon structures on both sides to 715 mV and the VOC of completed double-sided TOPCon bottom cells to 710 mV. Consequently, integrating with perovskite top cells, our proof of concept of 1 cm2 n-i-p perovskite/silicon TSCs exhibit VOCs exceeding 1.9 V and a high efficiency of 28.20% (certified 27.3%), which paves a way for TOPCon cells in the commercialization of future tandems. Perovskite/silicon tandem solar cells have attracted great attention for their efficiency and industry-compatible fabrication. Here, authors report a p-type tunnel oxide passivated contact structure with improved implied open-circuit voltage, achieving efficiency over 28% in 1 cm2 n-i-p tandem cells. [ABSTRACT FROM AUTHOR]

Addressing sustainable energy storage remains crucial for transitioning to renewable sources. While Li‐ion batteries have made significant contributions, enhancing their capacity through alternative materials remains a key challenge. Micro‐sized silicon is a promising anode material due to its tenfold higher theoretical capacity compared to conventional graphite. However, its substantial volumetric expansion during cycling impedes practical application due to mechanical failure and rapid capacity fading. A novel approach is proposed to mitigate this issue by incorporating trace amounts of aluminum into the micro‐sized silicon electrode using ball milling. Density functional theory (DFT) is employed to establish a theoretical framework elucidating how grain boundary sliding, a key mechanism involved in preventing mechanical failure is facilitated by the presence of trace aluminum at grain boundaries. This, in turn, reduces stress accumulation within the material, reducing the likelihood of failure. To validate the theoretical predictions, capacity retention experiments are conducted on undoped and Al‐doped micro‐sized silicon samples. The results demonstrate significantly reduced capacity fading in the doped sample, corroborating the theoretical framework and showcasing the potential of aluminum doping for improved Li‐ion battery performance. [ABSTRACT FROM AUTHOR]

In this study, we successfully obtained crystalline silicon from silica powder using a metal-induced crystallization method. For this purpose, powders were first prepared from organosilicon compounds and finely dispersed aluminum particles, then their metal-induced crystallization was carried out by annealing at the temperature of 570 °C. Powders of organosilicon compounds (tetraethoxysilane and polyethylhydrosiloxane) were prepared by different technological operations in order to determine precisely the presence of carbon in the product. The results showed that the presence of carbon in silica powder affects the production of crystalline silicon. In silica powders containing no carbon, the formation of crystalline substances does not occur at the annealing temperature of 570 °C. The results of this study are of great importance for the production of polycrystalline silicon powders obtained at reduced temperatures. [ABSTRACT FROM AUTHOR]

In recent years the mechanism of carrier transport through a junction of polycrystalline silicon (poly‐Si) on an interface oxide has been extensively discussed for passivating contacts of crystalline silicon‐based solar cells fabricated along the well‐established high temperature route. In the fired passivating contact (FPC) approach, no extended crystallization is foreseen which also modifies the properties of the junction. Herein, investigation of atmospheric pressure chemical vapor deposited (APCVD), phosphorus‐doped (n) poly‐Si is done, which is annealed at different temperatures and durations following the FPC approach. Symmetric lifetime samples show the passivation potential of the FPC approach with implied open circuit voltages (iVOC) values of up to 736 mV. Temperature‐dependent specific contact resistivity measurements applying the transfer length method on differently grown interface oxides are used to identify tunneling or pinhole transport, or a combination of both. It is found that a transition from tunneling to pinhole transport surprisingly takes place already for annealing durations of a few seconds and is primarily impacted by annealing temperature instead of duration. Pinhole magnification studies via tetramethylammonium etching and scanning electron microscopy (SEM) confirm the existence of pinholes in the interfacial oxides. [ABSTRACT FROM AUTHOR]

The paper considers the possibility of using the diamond‐silicon carbide composite Skeleton® with a technological coating of polycrystalline silicon as a substrate for X‐ray mirrors used with powerful synchrotron radiation sources (third+ and fourth generation). Samples were studied after polishing to provide the following surface parameters: root‐mean‐square flatness ≃ 50 nm, micro‐roughness on the frame 2 µm × 2 µm σ ≃ 0.15 nm. The heat capacity, thermal conductivity and coefficient of linear thermal expansion were investigated. For comparison, a monocrystalline silicon sample was studied under the same conditions using the same methods. The value of the coefficient of linear thermal expansion turned out to be higher than that of monocrystalline silicon and amounted to 4.3 × 10−6 K−1, and the values of thermal conductivity (5.0 W cm−1 K−1) and heat capacity (1.2 J K−1 g−1) also exceeded the values for Si. Thermally induced deformations of both Skeleton® and monocrystalline silicon samples under irradiation with a CO2 laser beam have also been experimentally studied. Taking into account the obtained thermophysical constants, the calculation of thermally induced deformation under irradiation with hard (20 keV) X‐rays showed almost three times less deformation of the Skeleton® sample than of the monocrystalline silicon sample. [ABSTRACT FROM AUTHOR]

Transfer and output characteristics of fully-depleted polycrystalline silicon thin film transistors, including both tail and deep acceptor-like trap states in bulk, in the above-threshold region with low drain bias are presented under low or high state density in the situation without or with interface charge, respectively. The characteristics are calculated by a simple surface-potential-based drain current model in the strong inversion region with valid bias condition explained, and 2D-device simulation. The above-threshold region is found to be divided into Regions I and II, with Vsi, indicating the channel beginning to be completely strongly-inverted and large currents, and explication of deviations between the model and simulation in Region I. The large-traps effect on the range of Region I and Vth in the high state density situation is discovered. [ABSTRACT FROM AUTHOR]

Polycrystalline silicon carbide (SiC) is a highly valuable material with crucial applications across various industries. Despite its benefits, processing this brittle material efficiently and with high quality presents significant challenges. A thorough understanding of the mechanisms involved in processing and removing SiC is essential for optimizing its production. In this study, we investigated the sawing characteristics and material removal mechanisms of polycrystalline silicon carbide (SiC) ceramic using a diamond wire saw. Experiments were conducted with high wire speeds of 30 m/s and a maximum feed rate of 2.0 mm/min. The coarseness value (Ra) increased slightly with the feed rate. Changes in the diamond wire during the grinding process and their effects on the grinding surface were analyzed using scanning electron microscopy (SEM), laser confocal microscopy, and focused ion beam (FIB)-transmission electron microscopy (TEM). The findings provide insights into the grinding mechanisms. The presence of ductile grinding zones and brittle fracture areas on the ground surface reveals that external forces induce dislocation and amorphization within the grain structure, which are key factors in material removal during grinding. [ABSTRACT FROM AUTHOR]

In this work, we investigate the device-to-device variations in the remanent polarization of metal–ferroelectric–insulator–metal stacks based on ferroelectric hafnium–zirconium–oxide (HZO). Our study employs a 3D dynamic multi-grain phase-field model to consider the effects of the polycrystalline nature of HZO in conjunction with the multi-domain polarization switching. We explore the dependence of variations on various design factors, such as the ferroelectric thickness and voltage stimuli (set voltage, pulse amplitude, and width), and correlate the trends to the underlying polarization switching mechanisms. Our analysis reveals a non-monotonic dependence of variations on the set voltage due to the coupled effect of the underlying polycrystalline structure variations and the voltage dependence of polarization switching mechanisms. We further report that collapsing of oppositely polarized domains at higher set voltages can lead to an increase in variations, while ferroelectric thickness scaling lowers the overall device-to-device variations. Considering the dynamics of polarization switching, we highlight the key role of voltage and temporal dependence of domain nucleation in dictating the trends in variations. Finally, we show that using a lower amplitude pulse for longer duration to reach a target mean polarization state results in lower variations compared to using a higher amplitude pulse for shorter duration. [ABSTRACT FROM AUTHOR]

The optical constants of single-crystal AlxGa1−xP and AlxGa1−xAs have been widely studied at various Al compositions but have not yet been thoroughly investigated as polycrystalline materials. Using variable-angle spectroscopic ellipsometry, we estimate and analyze the optical constants of polycrystalline Al0.25Ga0.75P and Al0.9Ga0.1As that were non-epitaxially deposited at deposition temperatures of either 250 or 420 °C, and with various dopant species, dopant concentrations, and V/III flux ratios. For wavelengths of 350–400 nm, decreasing the V/III ratio increases the refractive index of Be-doped polycrystalline Al0.25Ga0.75P. For wavelengths >500 nm, as the targeted Be dopant concentration increases for polycrystalline Al0.25Ga0.75P, the amount the extinction coefficient increases and the indirect bandgap decreases depends on the V/III ratio. Furthermore, Si-doped polycrystalline Al0.25Ga0.75P has significantly smaller extinction coefficient values than when it is Be-doped, for the same V/III ratio and targeted doping concentration, at wavelengths >500 nm. Based on our findings, we hypothesize that the dopant species, dopant concentration, and the V/III ratio dictate various types of defect concentrations, which then affect the optical constants and indirect bandgap of polycrystalline Al0.25Ga0.75P. Additionally, for wavelengths >500 nm, we find that polycrystalline Al0.25Ga0.75P and Al0.9Ga0.1As have the lowest extinction coefficient values when deposited at 420 °C, as opposed to 250 °C. Thus, we hypothesize that the deposition temperature is the most significant factor in dictating the optical constants of these polycrystalline III-Vs. Ultimately, this work demonstrates alternative methods to tune the optical constants of polycrystalline Al0.25Ga0.75P and Al0.9Ga0.1As, as opposed to tuning the Al composition. [ABSTRACT FROM AUTHOR]

In this article, we report on the basic physical properties of a polycrystalline Nb 5 Si 2 B sample, presenting and discussing experimental results of the temperature and field-dependent magnetization M(T, μ 0 H), heat capacity C p (T), electrical resistivity ρ (T), thermoelectric power S(T), and thermal conductivity κ (T) measurements. We also refer to the crystal structure properties of the obtained phase, but primarily we focus on determining the superconducting properties, because based on above experimental data, we deduce on the second-type bulk superconducting transition at T c ≃ 8.2 K. A set of characteristic superconducting state parameters was estimated. Interestingly, although T c gradually and regularly decreases with increasing magnetic field strength, scaling the temperature dependence of the upper critical field μ 0 H c 2 using the Werthamer–Helfand–Hohenberg (WHH) or Ginzburg–Landau (GL) theories does not reflect well on both models. The dimensionless specific heat jump at Δ C p / γ n T c attains ∼ 0.3 , which is significantly smaller than the classical BCS value of Δ C p / γ n T c = 1.43. In addition, the electronic specific heat C e l below T c does not reproduce the isotropic single-gap BCS behavior. Accordingly, these results indicate that Nb 5 Si 2 B is an unconventional BCS superconductor with an anisotropic or multi-valued gap. At T = 300 K, S(T) reaches a negative value of − 5.8 μ V/K and vanishes almost linearly with diminishing temperature, as expected for ordinary metals. On the other hand, from κ (T) data, it turns out that the lattice thermal conductivity dominates over the electronic contribution up to room temperature. [ABSTRACT FROM AUTHOR]

Polysilicon (poly-Si) passivating contacts have enabled some of the highest lab-scale crystalline silicon (c-Si) solar cell conversion efficiencies, largely due to their excellent surface passivation quality, which can be aided by means of hydrogenation treatments. One frequently applied method is to use hydrogen-rich capping layers, such as Al2O3 or SiNx, which can provide hydrogen to the poly-Si/SiOx/Si interface upon annealing. In this work, the effect of the deposition conditions of the Al2O3 layers, fabricated by various types of atomic layer deposition (ALD), on the hydrogenation of p+ poly-Si is investigated, and it is compared to the direct passivation of c-Si by the same Al2O3 layers. It is found that excellent hydrogenation of the p+ poly-Si by Al2O3 could be reached by a wide range of ALD conditions, but higher annealing temperatures were required as compared to passivation of c-Si. The different ALD conditions result in Al2O3 layers with varying refractive indices, O/Al ratios, and hydrogen content, although these material properties become highly similar upon annealing. Furthermore, the p+ poly-Si layer appears to act as a reservoir for hydrogen, which alters the hydrogen effusion profiles of the Al2O3 layers. The results show that a wide range of Al2O3 layers are highly suitable for hydrogenation of p+ poly-Si and provide more insight into the hydrogenation process of poly-Si passivating contacts. [ABSTRACT FROM AUTHOR]

Perovskite solar cells are among the most promising new solar technologies, already surpassing polycrystalline silicon solar cell efficiencies. The stability of the highest efficiency devices at elevated temperature is, however, poor. These cells typically use Spiro‐MeOTAD as the hole transporting layer. It is generally believed that additives, required for enhancing electrical conductivity and optimizing energy level alignment, are responsible for the reduced stability—inferring that Spiro‐MeOTAD based hole transporting layers are intrinsically unstable. Here, a reliable noble metal free synthesis of Spiro‐MeOTAD (bis(trifluoromethane)sulfonimide)4 is presented which is used as the oxidizing agent. No additives are added to the partially oxidized Spiro‐MeOTAD hole‐transporting layer. Device efficiencies up to 24.2% are achieved. Electrical conductivity is largely developed by the first 1% oxidation. Further oxidation shifts the energy levels away from the vacuum level, which allows tuning of the energy level alignment without the use of additives—contradicting the current understanding of this system. Without additives, devices demonstrate significant improvement in stability at elevated temperatures up to 85 °C under one sun over 1400 h continuous illumination. The remaining degradation is pinpointed to ion migration and reactions in the perovskite layer which may be further suppressed with compositional engineering and adequate ion barrier layers. [ABSTRACT FROM AUTHOR]

Palestine has limited energy sources and must import different fuels from neighboring countries, hence renewable energy sources like solar energy are necessary. One of the most important and promising clean renewable energy sources available today that also helps cut expenses and effort is solar energy. Solar energy is captured and stored by solar panels. Solar panels come in a wide variety now, and new kinds are always being developed to maximize solar energy absorption, require the least amount of maintenance, and endure a longer time. This study will compare the performance of the polycrystalline solar cell unit and the PERC unit, both of which will be impacted by Palestine's environment, by conducting an experimental investigation into the behavior of the unit. The PERC panel's temperature was lower than the polycrystalline panel's because of the addition of a heatreflecting layer, which increased the PERC panel's efficiency. The efficiencies of the two panels were compared at the same level of solar radiation. It has been demonstrated that PERC efficiency is higher when solar radiation is the same. The solar energy absorbed in the PERC panel actually increases because of the reflective coating that helps the PERC cell to optimize its benefit from the sun's radiation. When polycrystalline and PERC panels were compared, the former produced more electricity per unit of area. [ABSTRACT FROM AUTHOR]

Metabolites are essential molecules involved in various metabolic processes, and their deficiencies and excessive concentrations can trigger significant physiological consequences. The detection of multiple metabolites within a non‐invasively collected biofluid could facilitate early prognosis and diagnosis of severe diseases. Here, a metal oxide heterojunction transistor (HJ‐TFT) sensor is developed for the label‐free, rapid detection of uric acid (UA) and 25(OH)Vitamin‐D3 (Vit‐D3) in human saliva. The HJ‐TFTs utilize a solution‐processed In2O3/ZnO channel functionalized with uricase enzyme and Vit‐D3 antibody for the selective detection of UA and Vit‐D3, respectively. The ultra‐thin tri‐channel architecture facilitates strong coupling between the electrons transported along the buried In2O3/ZnO heterointerface and the electrostatic perturbations caused by the interactions between the surface‐immobilized bioreceptors and target analytes. The biosensors can detect a wide range of concentrations of UA (from 500 nm to 1000 µM) and Vit‐D3 (from 100 pM to 120 nm) in human saliva within 60 s. Moreover, the biosensors exhibit good linearity with the physiological concentration of metabolites and limit of detections of ≈152 nm for UA and ≈7 pM for Vit‐D3 in real saliva. The specificity is demonstrated against various interfering species, including other metabolites and proteins found in saliva, further showcasing its capabilities. [ABSTRACT FROM AUTHOR]

This paper explores the optimization of critical parameters in the Czochralski (CZ) crystal growth process, a key technique in semiconductor device manufacturing. The CZ system involves the melting of high-purity polycrystalline silicon and controlled growth of a single-crystal ingot. This process relies on key variables such as the thermal shield thickness, shield gap size, cooling jacket length, crucible dimensions, and rotation speed. A computational model was applied to simulate heat transfer, fluid flow, and radiation heat exchange within the CZ system. The model was validated using experimental data, which demonstrated its precision in predicting crystal-front deflection and heater power. The results highlight the substantial impact of increasing the thermal shield thickness on the crystal-pulling speed and uniformity. Greater cooling jacket lengths increased the cooling rate, which increased the pulling speed, although more heater power was required. The shield gap size had negligible effects, and variations in the heater power ratio showed minimal impact. The optimal combination of parameters led to significantly improved crystal-pulling speed and reduced power consumption, making it a compelling choice for enhanced CZ crystal growth in semiconductor manufacturing. [ABSTRACT FROM AUTHOR]

The diamond wire (DW) is widely used in the field of slicing semiconductor materials such as monocrystalline silicon and polycrystalline silicon. The quality of the wafer is greatly affected by the protrusion height consistency of the abrasives consolidated on the surface of the DW. However, the online detection accuracy of the abrasive protrusion height is still unsatisfactory, which is mainly caused by the rough DW image segmentation results. In this paper, a diamond wire image segmentation model (DWISM) is proposed based on deep learning. To improve the segmentation accuracy of the DW image, a hard-points selection component is designed to adaptively select difficult-to-predict pixels in high-frequency regions such as the edge of the abrasives. The feature vector extraction and category re-prediction of these points are implemented in a specially designed refine head. Extensive comparative experiments are implemented to verify the performance of the proposed method. The results show that DWISM could achieve 90.8 mean Intersection over Union (mIoU) with 11.22 Frames Per Second (FPS) inference speed. The promising results demonstrate the great potential of DWISM for improving the protrusion height online detection accuracy of the abrasives consolidated on the surface of DW. [ABSTRACT FROM AUTHOR]

A low‐thermal‐budget fabrication approach is developed to realize high‐performance fluorine‐doped indium oxide (In2O3:F) thin‐film transistors (TFTs) with remarkable bias‐stress stability. The ultrathin transistor channel layer is prepared by a re‐developed atomic layer deposition (ALD) process of using cyclopentadienyl indium(I) (InCp) and O2 plasma to deposit a crystalline In2O3 film, followed by a new fluorine doping strategy to use CF4 plasma to afford the In2O3:F layer. As revealed by the density functional theory (DFT) analysis, the fluorine doping can stabilize the lattice oxygen and electrically passivate the problematic VO defects in In2O3 by forming the FOFi spectator defects. Therefore, the fabricated In2O3:F TFTs show simultaneously excellent electrical performance and remarkable bias‐stress stability, with high µFE of 35.9 cm2 V−1 s−1, positive Vth of 0.36 V, steep SS of 94.3 mV dec−1, small hysteresis of 33 mV, and small ΔVth of −111 and 49 mV under NBS and PBS, respectively. This work demonstrates the high promise of the fluorinated ALD In2O3:F TFTs for the CMOS back‐end‐of‐line (BEOL) compatible technologies toward advanced monolithic 3D integration. [ABSTRACT FROM AUTHOR]

Polycrystalline silicon (poly‐Si) is essential in integrated circuits and microelectromechanical systems. In addition, poly‐Si is gaining attention for next‐generation display research with high thermal conductivity, stability, and versatile applications. Conventional fabrication methods for doping patterns involve complex lithography and chemical usage, which have raised environmental concerns. The study of novel methods is necessary for environmental friendliness and a significant simplification of the manufacturing processes. This study introduces a novel bipolar work function control technology utilizing deionized water (DI‐W) and nanonewton‐scale mechanical force using an atomic force microscope. The method is implemented with a mechanically induced SiOx layer on poly‐Si in DI‐W. The induced Si─OH and Si─O bonds decreases the work function, whereas a thicker SiOx layer with a high oxidation state increases the work function. Based on the magnitude of the applied force (26.73–75.24 nN) and additional DI‐W immersion, the induced bond and thickness of the SiOx layer are controlled. Therefore, bipolar work function control is achieved in the range of −0.25–+0.103 eV. In addition, the electrical characteristics of the fabricated p‐ and n‐type poly‐Si diodes are investigated. This method is eco‐friendly and enables bipolar doping patterns in a single process with high efficiency. [ABSTRACT FROM AUTHOR]

This study investigates the injection dependence of carrier lifetimes of p‐ and n‐type samples passivated by doped‐polycrystalline silicon (poly‐Si) (p+ and n+ poly‐Si) contacts. A strong apparent injection dependence of the carrier lifetimes is observed in p‐n junction samples (p+ poly‐Si on n‐type or n+ poly‐Si on p‐type) but no injection dependence is observed in high‐low junction samples (p+ poly‐Si on p‐type or n+ poly‐Si on n‐type). Further, photoluminescence images captured at two illumination intensities of 0.05 and 0.87 suns reveal that edge recombination contributed the strong apparent injection dependence in p‐n junction samples. Furthermore, this apparent injection dependence increases as the sample size is reduced, and as the sheet resistance of the doped poly‐Si contacts is decreased, allowing more effective transport of minority carriers to the recombination‐active edge regions. [ABSTRACT FROM AUTHOR]

Heteroepitaxial growth of γ‐Al2O3 on Sc2O3/Y2O3/Si (111) is achieved with oxygen plasma‐assisted molecular beam epitaxy in order to prevent polycrystalline grain boundary formation caused by lattice mismatch. Substrate temperature as well as oxygen flow are adjusted to optimize epitaxial growth conditions around 715–760 °C and 1.9 sccm, respectively. Epitaxial growth is monitored in situ by reflection high‐energy diffraction, while surface morphology is studied by scanning electron microscopy ex‐situ. X‐ray diffraction indicates epitaxial out‐of‐plane 111 orientation with oxygen flow above 0.6 sccm. However, transmission electron microscopy shows stacking fault formation for high oxygen flows. Finally, nanobeam electron diffraction confirms Smrčok model of a spinel‐like γ‐Al2O3 crystal structure. [ABSTRACT FROM AUTHOR]

The article discusses the development of a new scan circuit called Nscan GOA circuit that can reduce power consumption in mobile devices. The circuit achieves this by controlling the frequency of scan signals in different regions of the screen, resulting in a 10% reduction in power consumption for the GOA circuit and a 17.7% reduction in total IC power consumption compared to full screen frequency. The article provides a detailed explanation of the circuit's operation and its potential benefits for reducing power consumption in mobile devices. The proposed circuit offers potential benefits in reducing power consumption in displays. [Extracted from the article]

LTPO(Low Temperature Polycrystalline Oxide) is a hybrid backplane technology that combines low‐temperature polycrystalline silicon and oxide‐based TFT (thin‐film transistor). It is also one breakthrough technology that achieves ultra‐long standby time and stable battery life. This paper mainly discusses the key technical points of LTPO power saving [1][2] from the driver IC technology and screen technology solution, and also introduces the mass production results of Visionox LTPO technology, demonstrating the great potential of LTPO in low power comsumption. [ABSTRACT FROM AUTHOR]

This article proposes a mini‐LED pixel circuit that employs the PWM driving method to decrease power consumption. To achieve uniform current, the circuit compensates for threshold voltage variations of TFTs and VDD I‐R drops. Simulation results show that power consumption is ameliorated over 10.53% more than the 6T1C circuit. [ABSTRACT FROM AUTHOR]

The new AMOLED pixel circuit for high‐resolution applications such as AR/VR has been proposed. The simultaneous emission is adopted to minimize pixel elements. The proposed circuit can compensate for variations of threshold voltage and sub‐threshold voltage even composed with 3 TFTs and 1 capacitor. [ABSTRACT FROM AUTHOR]

We developed a flexible imager comprising low‐temperature polycrystalline silicon thin‐film transistors and organic photodiodes. The developed flexible imager has high‐resolution and high‐speed readout characteristics. Owing to these characteristics, pulse wave signals can be measured, and the images of fingerprints and veins can be obtained. Furthermore, we developed three‐axis tactile pressure sensors by integrating flexible optical components. The sensors can detect both normal and tangential pressures. [ABSTRACT FROM AUTHOR]

A new flexible low‐temperature polycrystalline silicon thin film transistors (LTPS TFTs) backplane on PI substrate with organic dielectric layer and low‐stress structure of island TFT is proposed. This new extremely low stress backplane is able to withstand 20,000 inward bending cycles at a bending radius of 1mm without any noticeable TFT degradation. After 200,000 bending inward cycles at bending radius of 1 mm, the stability test results show that the change of on‐current is 10.07% for hot carrier instability (HCI) test, the change of threshold voltage ‐0.31V for negative bias thermal instability (NBTI) test, the change of threshold voltage ‐0.24V for hysteresis test, and the breakdown voltage of gate insulator 7.73MV/cm, respectively. The AMOLED display panel manufacured with organic ILD does not show any visible degradation of panel image just after 200K rolling at rolling radius of 4mm or 200K folding at folding radius of 1mm. [ABSTRACT FROM AUTHOR]

The grain size effect is an important factor in determining the material removal behavior of polycrystalline silicon (p-Si). In the present study, to improve the understanding of nanoscale machining of p-Si, we performed molecular dynamics simulation of nanometric cutting on a p-Si workpiece and discussed the grain size effect on material removal behavior and subsurface damage formation. The simulation results indicate that when cutting on the polycrystal workpiece, the material removal process becomes unstable compared with single crystals. Higher removal efficiency, less elastic recovery and higher frictional coefficient are observed as the average grain size decreases. In the subsurface workpiece, when the grain size decreases, slip along grain boundaries merges as a nonnegligible process of the plastic deformation and suppresses the elastic deformation ahead of the cutting tool. It is also revealed that when cutting on a polycrystal workpiece with smaller grains, the average stress decreases while the workpiece temperature increases due to the impediment of heat transfer by grain boundaries. These results could provide a fundamental understanding in the material deformation mechanism of p-Si during nanoscale machining. [ABSTRACT FROM AUTHOR]

Engineering of interfaces and point defects in ferroelectric memristors is an efficient way for manipulating the resistive switching effects of mixed ionic‐electronic nature. However, an interplay between the defects, interfacial properties, and ferroelectric polarization as well as their influence on the resistance state tuning are yet to be revealed. By considering the memristive device built on a thin polycrystalline BaTiO3 film, a drift‐diffusion model of non‐stationary processes is developed. The model is based on Poisson and continuity equations solved numerically and accounts for various transport mechanisms for electrons, holes, and oxygen vacancies. Comparing simulated resistive effects with experimental data taken in a wide temperature range, it is shown that an appearance of the analog resistive switching cannot be explained solely by oxygen‐ionic transport. Investigated switching dynamics claims the oxygen vacancies redistribution to be responsible for the analog character of the switching at the prevalence of the electron hopping transport. Crucially, the required dynamics of the vacancies redistribution is achieved only in a narrow range of their mobility. These results can be used in designing the ferroelectric memristors for nonvolatile multilevel memory devices satisfying the requirements that arise at the stages of their integration into neuromorphic architectures. [ABSTRACT FROM AUTHOR]

Thin polysilicon (poly-Si)-based passivating contacts can reduce parasitic absorption and the cost of n-TOPCon solar cells. Herein, n+-poly-Si layers with thicknesses of 30~100 nm were fabricated by low-pressure chemical vapor deposition (LPCVD) to create passivating contacts. We investigated the effect of n+-poly-Si layer thickness on the microstructure of the metallization contact formation, passivation, and electronic performance of n-TOPCon solar cells. The thickness of the poly-Si layer significantly affected the passivation of metallization-induced recombination under the metal contact (J0,metal) and the contact resistivity (ρc) of the cells. However, it had a minimal impact on the short-circuit current density (Jsc), which was primarily associated with corroded silver (Ag) at depths of the n+-poly-Si layer exceeding 40 nm. We introduced a thin n+-poly-Si layer with a thickness of 70 nm and a surface concentration of 5 × 1020 atoms/cm3. This layer can meet the requirements for low J0,metal and ρc values, leading to an increase in conversion efficiency of 25.65%. This optimized process of depositing a phosphorus-doped poly-Si layer can be commercially applied in photovoltaics to reduce processing times and lower costs. [ABSTRACT FROM AUTHOR]

Large-size electronic-grade polycrystalline silicon is an important material in the semiconductor industry with broad application prospects. However, electronic-grade polycrystalline silicon has extremely high requirements for production technology and currently faces challenges such as carbon impurity breakdown, microstructure and composition nonuniformity and a lack of methods for preparing large-size mirror-like polycrystalline silicon samples. This paper innovatively uses physical methods such as wire cutting, mechanical grinding and ion thinning polishing to prepare large-size polycrystalline silicon samples that are clean, smooth, free from wear and have clear crystal defects. The material was characterized at both macroscopic and microscopic levels using metallographic microscopy, scanning electron microscopy (SEM) with backscattered electron diffraction (EBSD) techniques and scanning transmission electron microscopy (STEM). The crystal structure changes from single crystal silicon core to the surface of the bulk in the large-size polycrystalline silicon samples were revealed, providing a technical basis for optimizing and improving production processes. [ABSTRACT FROM AUTHOR]

This paper focuses on the problems encountered in the production process of electronic-grade polycrystalline silicon. It points out that the characterization of electronic-grade polycrystalline silicon is mainly concentrated at the macroscopic scale, with relatively less research at the mesoscopic and microscopic scales. Therefore, we utilize the method of physical polishing to obtain polysilicon characterization samples and then the paper utilizes metallographic microscopy, scanning electron microscopy-electron backscatter diffraction technology, and aberration-corrected transmission electron microscopy technology to observe and characterize the interface region between silicon core and matrix in the deposition process of electronic-grade polycrystalline silicon, providing a full-scale characterization of the interface morphology, grain structure, and orientation distribution from macro to micro. Finally, the paper illustrates the current uncertainties regarding polycrystalline silicon. [ABSTRACT FROM AUTHOR]

Ultra-flat, ultra-thin alkali antimonide photocathodes with high crystallinity can exhibit high quantum efficiency and low mean transverse energy of outgoing electrons, which are essential requirements for a variety of applications for photocathode materials. Here, we investigate the growth of Cs3Sb on graphene-coated 4H–SiC (Gr/4H–SiC), 3C–SiC, and Si3N4 substrates. Sb is deposited using pulsed laser deposition, while Cs is deposited thermally and simultaneously. We demonstrate, employing x-ray analysis and quantum efficiency measurements, that this growth method yields atomically smooth Cs3Sb photocathodes with a high quantum efficiency (>10%), even in the ultra-thin limit (<30 nm). For the Si3N4 substrate, film growth is shown to be polycrystalline, while films grown on Gr/4H–SiC show a high degree of ordering with signs of epitaxy. [ABSTRACT FROM AUTHOR]

Tunnel oxide passivated contact (TOPCon) silicon solar cells have been developed and transferred into industrial mass production, which is beneficial to the future production of perovskite/silicon tandem solar cells (TSCs) in a large scale. However, the doped polycrystalline silicon (poly‐Si) layer in the poly‐Si‐based passivating contact structure yields a profound optical loss from reflection and parasitic absorption, which obstacles the efficiency promotion of TSCs. In this work, the optical property of poly‐Si is improved by in‐situ oxygen incorporation using plasma enhanced chemical vapor deposition (PECVD) with nitrous oxide (N2O) as the oxygen source. The p‐type oxygen‐incorporated poly‐Si (poly‐SiOx) shows a reduced refractive index and extinction coefficient over 700–1200 nm wavelength, leading to a reduced reflection, a lower parasitic absorption and a higher transmission. After applying an optimized p‐type oxygen‐incorporated poly‐Si in the front‐side poly‐Si passivating contact structure of c‐Si bottom cell, the short‐circuit current density and efficiency of a perovskite/c‐Si tandem cell increases by ≈0.32 mA cm−2 and ≈0.8%, respectively, leading to 25.12% tandem cell efficiency. [ABSTRACT FROM AUTHOR]

In the face of ever‐evolving energy and environmental challenges, tin selenide (SnSe) has garnered significant attention due to its outstanding thermoelectric performance. The article focuses on the research of easily accessible and highly practical polycrystalline SnSe thermoelectric materials, providing an overview of their crystal structure, band structure, and electrical transport performance. Compared with previous studies, this research classifies elements based on their own properties, mainly dividing them into alkali metals, transition metals, main group metals, halogens, and rare earth (Re) elements. The study systematically summarizes the experimental results of doping SnSe with these elements and analyzes the mechanisms by which different elements enhance the electrical transport performance and thermoelectric figure of merit of polycrystalline SnSe. The enhanced mechanism is mainly achieved by increasing the conductivity and Seebeck coefficient. Finally, a systematic analysis is conducted to identify the factors that improve electrical transport performance, and strategies for enhancing the electrical transport and thermoelectric properties of polycrystalline SnSe through precise doping techniques are discussed, with a prospect for their application in the future. [ABSTRACT FROM AUTHOR]

This paper reports the development and integration of (Poly‐Si/Air)n Distributed BRAGG Reflectors (DBR) in a MOEMS Fabry‐Pérot‐Interferometer (FPI) concept. The realized reflectors constitute a promising and resource‐efficient alternative to complex Ion‐Assisted Deposition based DBRs while maintaining their advantages. Compared to state of the art MOEMS FPIs the (Poly‐Si/Air)n DBRs can be integrated into two moveable reflector carriers based on two individually fabricated wafers which are bonded. The (Poly‐Si/Air)n DBRs are investigated as (HL) and (HL)2 reflector stacks showing a reflectance above 91% within the wavelength range of 2.8–5.7 μm. © 2023 The Authors. IEEJ Transactions on Electrical and Electronic Engineering published by Institute of Electrical Engineer of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

A new flexible low‐temperature polycrystalline silicon thin film transistors (LTPS TFTs) on PI substrate with organic ILD layer, island TFT, and TFT channel perpendicular to stress direction was proposed. AMOLED display panel manufactured with organic ILD did not show any visible degradation of panel image after outward rolling cycles of 200,000 at rolling radius of 4 mm or inward folding cycles of 200,000 at folding radius of 1 mm. Another novel structure of TFT with channel perpendicular to stress direction significantly reduced change of threshold voltage of −0.03 V compared with change of threshold voltage of −0.6 V for TFT with channel parallel to stress direction for reliability test of high drain current (HDC) after 100,000 outward‐bending cycles at bending radius of 3 mm. After inward‐bending cycles of 200,000 at bending radius of 1 mm, reliability test results for TFT device with organic ILD layer showed that change of on‐current is 10.07% for hot carrier instability (HCI) test, change of threshold voltage −0.31 V for negative bias thermal instability (NBTI) test, change of threshold voltage −0.24 V for hysteresis test, and breakdown voltage of gate insulator 7.73 MV/cm, respectively, and these performances are similar to those of TFT device with inorganic ILD (SiNx). [ABSTRACT FROM AUTHOR]

This article presents an analysis of the performance of a 14.04 kWp grid-connected photovoltaic (PV) installation consisting of monocrystalline silicon, polycrystalline silicon and bifacial glass–glass monocrystalline silicon modules. The photovoltaic system was mounted in Poland, a location characterized by temperate climate conditions. On the basis of the obtained results, the photovoltaic parameters were determined in accordance with the international standard. The annual energy yield of the entire system was 1033 kWh/kWp, and the performance ratio achieved was 83%. The highest average daily final yield was in the range of 4.0–4.5 kWh/kWp for each photovoltaic technology under investigation. In the cold part of the year, the efficiency of the photovoltaic modules was estimated to be 15%, and it was estimated to be 7% during the warm part of the year. Array capture losses accounted for around 0.75 kWh/kWp of energy loss per day, whereas the inverter efficiency was over 95% during the months that are beneficial for energy production. [ABSTRACT FROM AUTHOR]

A bottom-up method is described to grow patterned polycrystalline diamond on silicon substrates using polymer assisted seeding and photolithography. Diamond seeding densities were > 1011 cm−2. The pattern consists of well-defined features ranging from microns to millimeters in size. A systematic study was carried out to investigate the effects of CH4 concentration (1.5, 2.0, 2.5, and 3.0% in H2) on diamond grown using hot-filament chemical vapor deposition. The study is focused on the early growth regime following 30 min, 45 min, and 2 h process times. Scanning electron microscopy and atomic force microscopy measurements are used to study thickness, growth rate, grain size, grain morphology, and surface roughness of the polycrystalline diamond. SEM cross section images confirm the growth of high seeding diamond films without voids at the substrate interface. An increasing trend of lateral particles sizes, with increasing CH4, is observed reaching ~ 365 nm at the highest CH4 concentration. Material quality is checked using UV micro-Raman spectroscopy including line scans to investigate uniformity of patterned features. The results show that higher CH4 concentration leads to narrow linewidths and higher relative integrated intensities of diamond. These characteristics are consistent with improvements in the diamond quality in the early growth stages. [ABSTRACT FROM AUTHOR]

Solar cells have been developed as a highly efficient source of alternative energy, collecting photons from sunlight and turning them into electricity. On the other hand, ultraviolet (UV) radiation has a substantial impact on solar cells by damaging their active layers and, as a result, lowering their efficiency. Potential solutions include the blocking of UV light (which can reduce the power output of solar cells) or converting UV photons into visible light using down-conversion optical materials. In this work, we propose a novel hydrophobic coating based on a polydimethylsiloxane (PDMS) layer with embedded red emitting Y2O3:Eu3+ (quantum yield = 78.3%) particles for UV radiation screening and conversion purposes. The favorable features of the PDMS-Y2O3:Eu3+ coating were examined using commercially available polycrystalline silicon solar cells, resulting in a notable increase in the power conversion efficiency (PCE) by ~9.23%. The chemical and UV stability of the developed coatings were assessed by exposing them to various chemical conditions and UV irradiation. It was found that the developed coating can endure tough environmental conditions, making it potentially useful as a UV-protective, water-repellent, and efficiency-enhancing coating for solar cells. [ABSTRACT FROM AUTHOR]

The design of new complex mixed metal tellurides (containing low toxicity cations) with intrinsic ultralow thermal conductivity is of paramount importance in the field of thermoelectrics. Herein, we report the synthesis and characterization of polycrystalline and single crystals of a new mixed-metal quaternary telluride Mn1.8(1)In0.8(1)Si2Te6. The structural aspects and chemical formula of this phase at room temperature have been established using single crystal X-ray diffraction and EDX studies. The trigonal centrosymmetric (space group: P3-1m) structure of the title phase has cell constants of a = b = 7.0483(7) Å and c = 7.1277(8) Å. The structure has three independent cationic sites, one mixed (In1/Mn1), one partially filled Mn2, and one Si1, which are bonded with Te1 atoms. Each metal atom (In and Mn) in the structure is octahedrally coordinated with six neighboring Te1 atoms. The structure also features dimers of Si atoms, and each Si atom is bonded to three Te1 atoms to form ethane-like Si2Te6 units. The optical absorption study of a polycrystalline Mn1.8In0.8Si2Te6 sample shows a narrow optical bandgap of 0.6(2) eV. Temperature-dependent resistivity and Seebeck coefficient studies confirmed the p-type semiconducting nature of the sample with high values of S (301 μV K-1 to 444 μV K-1). The total thermal conductivity (ktot) study of the polycrystalline sample shows a decreasing trend on heating with an extremely low value of 0.28 W m-1 K-1 at 773 K. Magnetic measurements indicate a glassy magnetic behavior for the sample below 8 K. [ABSTRACT FROM AUTHOR]

Silver (Ag) paste is widely used in semiconductor metallization, especially in silicon solar cells. Ag powder is the material with the highest proportion in Ag paste. The morphology and structure of Ag powder are crucial which determine its characteristics, especially for the sintering activity. In this work, a simple method was developed to synthesize a type of microcrystalline spherical Ag particles (SP-A) with internal pores and the structural changes and sintering behavior were thoroughly studied by combining ultra-small-angle X-ray scattering (USAXS), small-angle X-ray scattering (SAXS), in-situ heating X-ray diffraction (XRD), focused ion beam (FIB), and thermal analysis measurement. Due to the unique internal pores, the grain size of SP-A is smaller, and the coefficient of thermal expansion (CTE) is higher than that of traditional solid Ag particles. As a result, the sintering activity of SP-A is excellent, which can form a denser sintered body and form silver nanoparticles at the Ag–Si interface to improve silver silicon contact. Polycrystalline silicon solar cell built with SP-A obtained a low series resistance (Rs) and a high photoelectric conversion efficiency (PCE) of 19.26%. These fill a gap in Ag particle structure research, which is significant for the development of high-performance electronic Ag particles and efficient semiconductor devices. [ABSTRACT FROM AUTHOR]

A compact gate driver using p‐type low‐temperature polycrystalline silicon (LTPS) thin‐film transistors (TFTs) was proposed for Micro‐Light Emitting diodes (μLEDs) display using progressive emission analog pulse‐width modulation (A‐PWM) approach. The gate driver contains a simple waveform shaping module and outputs multiple sweep signals, including SW[n], EM[n], and S[n], by reusing the bootstrap node. Compared with conventional schemes, the proposed gate driver renders static power consumption reduction of the μLED display by 29.2%. [ABSTRACT FROM AUTHOR]

This paper discusses critical performance metrics wit hin active matrix pixel circuits that occur between acti vation stages (i.e. between programming and emission). It uses an all amorphous oxide semiconductor (AO S) 2T1C (2‐transistor, 1‐capacitor) pixel circuit to dem onstrate kickback voltage, charge sharing, and charge rejection through simulation and experimentation. [ABSTRACT FROM AUTHOR]

Low refresh rate liquid crystal displays have been proposed to reduce power consumption, which is already the trend. In our early low‐temperature polycrystalline silicon liquid crystal displays, low‐frequency driving caused the screen to flicker. We investigated the flicker mechanism and improvement solutions in this paper. The flicker mechanism is mainly related to thin‐film transistor leakage current, capacitive coupling effect, and cell material property. By adopting some solutions, the flicker of gray level 127 can reach‐60dB in a 20Hz 13.5‐inch 2.8K demo. These results contribute to the development of low‐power consumption displays. [ABSTRACT FROM AUTHOR]