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Paper is a cheap substrate which is in principle compatible with the process temperature applied in the plasma enhanced chemical vapour deposition (PECVD) and hot wire CVD (HWCVD) of thin film silicon solar cells. The main drawback of paper for this application is the porosity due to its fibre like structure. The feature size (micrometre scale) is larger than the thickness of the applied photovoltaic layers. To overcome this problem, UV curable lacquer was used to planarize the surface. Plain 80 grams printer paper was taken as a substrate and the lacquer smoothens the rough surface of the paper such that a designed nanostructure can be imprinted for light scattering. In this manner single junction amorphous silicon solar cells with a HWCVD deposited intrinsic layer were processed on paper, without any concessions to the process temperature of 200 °C. The cell performance is comparable to that of reference cells grown on stainless steel, proving that solar cells can be deposited on paper substrates without sacrificing performance. PV on paper could be applied as "disposable" power source for gadgets, electronic labelling, remote sensing systems, etc. (Internet of Things). [ABSTRACT FROM AUTHOR]

The emerging microfluidic tools bring new methods for miniaturized analytical systems and single cells manipulation. This study presents an active‐matrix digital microfluidic platform for single cells generation and manipulation. The microfluidic chip was fabricated by amorphous silicon (a‐6i) thin‐film transistor (TFT) technology. The active device contains 26,368 electrodes that can be independently addressed to perform multiple and simultaneous droplets manipulation. The electrode array consists of electrodes differing in shape and size. The combination of various electrodes can give full play of their advantages, thus improve the droplet movement stability and generation uniformity. This work paves new ways for conducting low‐cost and high‐throughput applications in single cells manipulation. [ABSTRACT FROM AUTHOR]

Vertical, organic, light‐emitting transistors (VOLETs) combine three of the four essential components of an active matrix lightemitting diode (AMOLED) pixel ‐ the drive transistor, the storage capacitor, and the OLED stack ‐ into a single, highly‐stable, selfemissive structure. VOLETs can be manufactured on amorphous silicon (a‐Si) thin‐film transistor (TFT) backplanes to enable lowcost AMOLED displays with improved brightness and lifetime characteristics. We report on the current status of VOLET development and prospective impact on the active‐matrix display industry. [ABSTRACT FROM AUTHOR]

Digital microfluidics have great advantages in improving droplets throughput and miniaturizing analytical systems. Digital microfluidics platform can bring new opportunities for chemical and biological analysis. Here we present an active‐matrix digital microfluidics platform for applications in high‐throughput micro‐droplets manipulation. The microfluidic chip was fabricated by amorphous silicon thin‐film transistor technology. The electrode array consists of 65536 electrodes, which possesses the ability to manipulate thousands of independent droplets simultaneously. This work paves new ways for conducting high‐throughput and low‐cost applications in chemical and biological analysis. [ABSTRACT FROM AUTHOR]

The electron mobility based on low temperature polysilicon is almost 100 times that of amorphous silicon, so low temperature polysilicon technology has overwhelming advantages in high pixel density, high refresh rate, narrow frame and other aspects. This paper will focus on the application of LTPS technology in the future high‐end notebook, mainly from the four dimensions of narrow border, power consumption, wide frame rate (WFR) ,low power consumption and incell, and discuss the industry trends, the technical bottlenecks of LTPS process and the current progress made by CSOT in these points. At present, LTPS technology has took a piece of the cake in the high‐end notebook market, and definitely present. Through the above introduction we believe that with the continuous breakthrough of LTPS technology bottleneck, it will bring a new chapter in the development of high‐end notebook. [ABSTRACT FROM AUTHOR]

Direct deposition of hydrogenated amorphous silicon (a-Si:H) thin films and fabrication of solar cells on polyimide (PI) and photo-paper (PP) substrates using a rf-plasma-enhanced chemical vapor deposition technique is reported. Intrinsic amorphous silicon films were deposited on PI and PP substrates by varying the substrate temperature (Ts) over 70-150°C to optimize the deposition parameters for best quality films. The films deposited on both PI and PP substrates at a temperature as low as 70°C showed a photosensitivity (σph/σd) of nearly 4 orders of magnitude which increased to 5-6 orders of magnitude when the substrate temperature was increased to 130-150°C. The increase in σph/σd is due to the presence of a few nanometer-sized crystallites embedded in the film. Solar cells (n-i-p) were fabricated directly on PI, PP and Corning 1737 glass (Corning) at 150°C for different thicknesses of an intrinsic amorphous silicon layer (i-layer). With the increase in i-layer thickness from 330 nm to 700 nm, the solar cell efficiency was found to increase from 3.81% to 5.02% on the Corning substrate whereas on the flexible PI substrate an increase from 3.38% to 4.38% was observed. On the other hand, in the case of cells on PP, the i-layer thickness was varied from 200 nm to 700 nm and the best cell efficiency 1.54% was obtained for the 200-nm-thick i-layer. The fabrication of a-Si (n-i-p) solar cells on photo-paper is presented for the first time. [ABSTRACT FROM AUTHOR]

We will proposed new silicon crystallization annealing technology using blue laser diode, proprietary optic fiber transfer and optic projection system. The new optical system produces rectangle top‐hat‐shaped irradiation onto substrate surface. By the new system, the heating and cooling can be controlled, obtained silicon crystal can be controlled from poly silicon, lateral silicon and single crystal. The large‐grain‐size lateral silicon crystal and single crystal silicon have great potential in displays and sensor devices because their higher carrier mobility and higher reliability. [ABSTRACT FROM AUTHOR]

Flexible thin-film solar cells with high weight-specific power density are highly desired in the emerging portable/wearable electronic devices, solar-powered vehicles, etc. The conventional flexible metallic or plastic substrates are encountered either overweight or thermal and mechanical mismatch with deposited films. In this work, we proposed a novel substrate for flexible solar cells based on graphene paper, which possesses the advantages of being lightweight and having a high-temperature tolerance and high mechanical flexibility. Thin-film amorphous silicon (a-Si:H) solar cells were constructed on such graphene paper, whose power density is 4.5 times higher than that on plastic polyimide substrates. In addition, the a-Si:H solar cells present notable flexibility whose power conversion efficiencies show little degradation when the solar cells are bent to a radius as small as 14 mm for more than 100 times. The application of this unique flexible substrate can be extended to CuInGaSe and CdTe solar cells and other thin-film devices requiring high-temperature processing. [ABSTRACT FROM AUTHOR]

Amorphous indium‐gallium‐zinc oxide (IGZO) thin‐film transistors (TFTs) with or without fluorinated channels were fabricated. The sensitivity of their electrical characteristics to hydrogen exposure was compared. It is shown that those built with fluorinated IGZO exhibit improved intrinsic resistance against hydrogen‐induced degradation. Such improvement correlates well with the reduced incorporation of hydrogen in the fluorinated channels, as revealed by secondary ion‐mass spectrometry. Fluorinated IGZO TFTs are better suited for integration with hydrogen‐containing devices, such as photo‐diodes based on amorphous hydrogenated silicon and TFTs based on low‐temperature polycrystalline silicon. [ABSTRACT FROM AUTHOR]

We report data of organic transistors on plastic with mobility values greater than 1cm2 /Vs. This technology enables LCDs that are thin, lightweight, shatterproof and flexible using transistors that outperform the existing standard of amorphous silicon on glass. We demonstrate the potential of our technology with a curved 12.1' Organic LCD. [ABSTRACT FROM AUTHOR]

By comparing the performance indicators of the three different types of TFT‐LCD process technology, low‐temperature polysilicon (LTPS), oxide and amorphous silicon (a‐Si) products, it is found that LTPS, due to its high electron mobility, can meet the future demand for high‐end notebook products, covering the product types of long‐lasting, light and thin business notebooks, high‐brightness and wide frame rate (WFR) gaming notebooks, in which LTPS products have shown obvious advantages. Through the analysis of the existing LTPS technology, the development trend of high‐end notebooks in the next few years is given, including LCM border, power consumption, WFR and in‐cell touch. [ABSTRACT FROM AUTHOR]

In thin film deposition, Ar/SiH4 mixtures are widely used to make polysilicon (poly-Si) and hydrogenated amorphous silicon (a-SiH) layers. Despite extensive research conducted on this mixture, little research has focused on the variations in plasma properties, radicals, and ions that occur during plasma discharge in inductively coupled plasma (ICP) equipment compared to capacitive coupled plasma equipment. In this paper, we investigate the properties of the plasma generated through mathematical modeling of Ar/SiH4 inductive coupled plasma discharge by using the electron energy distribution function (EEDF) obtained by solving the Boltzmann equation. We closely examine the variation in plasma properties and the correlation of plasma variables by controlling the radio frequency power and gas pressure during the process conditions. The Boltzmann equation was computed by assuming the two-term approximation, resulting in a Druyvesteyn-like EEDF due to the high-pressure conditions. To validate the simulation model, the 2D simulation results were compared with probe measurements performed in a two-turn ICP chamber. The results demonstrated encouraging agreement with the measured data. This research not only enhances our comprehension of the discharge characteristics but also establishes a framework for optimizing the discharge conditions to enhance the process and effectively regulate external variables. [ABSTRACT FROM AUTHOR]

This paper presents a product combining amorphous silicon solar cells and ESL. This product combines the amorphous silicon solar cell process with the TFT backplane of ESL products. At the same time, this product uses solar cells as the device for collecting light energy, and the new energy conversion equipment collects the electric energy generated by solar energy and generates stable output electric energy to provide ESL devices. This scheme is not only environmentally friendly, but also reduces the thickness of products using external solar cells. [ABSTRACT FROM AUTHOR]

Semiconductor blue laser diode was used for crystallization annealing of amorphous silicon of backplane of flat panel display. The grain size of result crystal can be controlled by laser beam intensity or beam scanning speed. The poly silicon produced by BLDA showed same characteristics as ELA in LTPS. Lateral crystal have been produced by BLDA, its field mobility is three times higher than poly silicon by ELA. A multiple head equipment is proposed, by which high performance TFT can be made with significantly lower cost comparing to conventional laser anneal technology. [ABSTRACT FROM AUTHOR]

This paper investigated the effect of PbS quantum dots on the efficiency of the amorphous silicon thin-film Schottky solar cell. By using the numerical method of finite-difference time-domain (FDTD), the short circuit current, open circuit voltage, fill factor, and efficiency of the proposed amorphous silicon thin-film Schottky solar cell were calculated. In the proposed solar cell, by changing the dimension and period of PbS quantum dots, the solar cell parameters were optimized. According to the simulation results, increasing the size of the quantum dots increased their light absorption associated with their cross-sectional area, decreased their band gap and the open-circuit voltage, and increased the number of wavelengths absorbed and the short-circuit current as well as the efficiency of the solar cell, increased the work functions of top contact cause to increase the efficiency of the solar cell and also raised the fill factor. Moreover, increasing the period of quantum dots did not change the open-circuit voltage, reduced the short-circuit current, and therefore lowered the efficiency of the solar cell. According to the simulation results, the value of 0.2104, or 3.86 times the efficiency without nanoparticles, is reached for Quantum Dot PbS with an 8 × 8 nm size and a 10 nm period to achieve the highest efficiency. [ABSTRACT FROM AUTHOR]

This paper proposes two types of electro-refractive optical modulator structures as a fully CMOS-compatible alternative solution. These modulators leverage the properties of amorphous (top) and crystalline (bottom) silicon films surrounding silicon nitride waveguides operating in the C-band communications range at a wavelength of 1550 nm. Various structures have been demonstrated and explored to compete with or surpass the current state-of-the-art performance of thermal tuners, the most widely used tuning mechanism in silicon nitride integrated photonics. Designs utilizing vertical and lateral p–n junctions with amorphous or crystalline films have been simulated and proposed. For the lateral p–n junctions, modulator lengths to achieve a π phase shift smaller than 287 μm have been demonstrated for the TE mode and that smaller than 1937 μm for the TM mode, reaching 168 μm in the case of a lateral p–n junction that is completely a p-doped region over or under the waveguide for TE, and 1107 μm for TM. Power consumption is higher for the TM modes than for the TE, being in the order of 100 mW for the former and lower than 23 mW for the latter. The modulators exhibit higher losses for amorphous material compared to crystalline, with losses smaller than 10.21 dB and 3.2 dB, respectively. The vertical p–n junctions present a larger footprint than the lateral ones, 5.03 mm for TE and 38.75 mm for TM, with losses lower than 3.16 dB and 3.95 dB, respectively, for the crystalline silicon. Also, their power consumption is on the order of 21 mW for TE and 164 mW for TM. [ABSTRACT FROM AUTHOR]

One of the major barriers to broad market adoption of reflective ePaper displays has been the difficulty in developing displays capable of video speeds and reflected brightness high enough to achieve full color. This paper summarizes the progress of active‐matrix high‐resolution eTIR displays exhibiting both a high‐contrast, high‐reflectance monochrome ink‐on‐paper look as well as video level switching speeds and full color using low‐cost color filters. We demonstrate a 9.7" full‐color video eTIR display with 227 ppi resolution. [ABSTRACT FROM AUTHOR]

This paper presents the history of the development of heterojunction silicon solar cells from the first studies of the amorphous silicon/crystalline silicon junction to the creation of HJT solar cells with novel structure and contact grid designs. In addition to explanation of the current advances in the field of research of this type of solar cells, the purpose of this paper is to show possible ways to improve the structure of the amorphous silicon/crystalline silicon-based solar cells for further improvement of the optical and electrical parameters of the devices by using of numerical simulation method and current hypotheses. This paper briefly describes the history, beginning from the first studies of and research of HJT-structure solar cells. It raises questions about the advantages and existing problems of optimization of HJT solar cells. The authors of this paper are proposing further ways of design development of HJT solar cells. [ABSTRACT FROM AUTHOR]

In this paper, we have developed a physics-based analytical model for the electrical characteristics of passivated silicon carrier-selective contact (CSC) solar cells and validated it with numerical simulations. The model comprises analytical solutions of: 1) the Poisson equation, accurately capturing the level of inversion and accumulation at the crystalline silicon (c-Si) layer interfaces, and 2) the recombination current capturing the various recombination mechanisms at work in the solar cell. The calculations establish that CSC solar cells have the potential to achieve an efficiency greater than 26% even when both c-Si interfaces have realistic SRV values of 100 cm/s. The model helps illustrate the physics underlying the performance of CSC solar cells for variation in key device parameters such as surface recombination velocities, bulk lifetime, contact layer doping, and amorphous silicon (a-Si) thickness amongst others. By circumventing the need for resource-intensive numerical simulations, the analytical model described in this paper can assist in the design and development of high-performance CSC solar cells. [ABSTRACT FROM AUTHOR]

The year 2014 marks the point when silicon solar cells surpassed the 25% efficiency mark. Since then, all devices exceeding this mark, both small and large area, with contacts on both sides of the silicon wafer or just at the back, have utilized at least one passivating contact. Here, a passivating contact is defined as a group of layers that simultaneously provide selective conduction of charge carriers and effective passivation of the silicon surface. The widespread success of passivating contacts has prompted increased research into ways in which carrier‐selective junctions can be formed, yielding a diverse range of approaches. This paper seeks to classify passivating contact solar cells into three families, according to the material used for charge‐carrier selection: doped amorphous silicon, doped polycrystalline silicon, and metal compounds/organic materials. The paper tabulates their current efficiency values, discusses distinctive features, advantages, and limitations, and highlights promising opportunities going forth towards even higher conversion efficiencies. The widespread success of passivating contacts has prompted increased research into ways in which carrier‐selective junctions can be formed, yielding a diverse range of approaches for silicon solar cells. This paper seeks to classify passivating contact solar cells into three families, according to the material used for charge‐carrier selection: Doped amorphous silicon, doped polycrystalline silicon, and metal compounds/organic materials. The paper tabulates their current efficiency values, discusses distinctive features, advantages, and limitations, and highlights promising opportunities going forth towards even higher conversion efficiencies. [ABSTRACT FROM AUTHOR]

The results of the numerical-analytical modeling of the photoconductivity of crystalline silicon with the inclusion of amorphous silicon are presented. These ones can be used in studying the principles of a new class of photovoltaic converters based on modified semiconductor materials. The initial data for such a model should be experimentally obtained layer parameters. During the calculations, it was assumed that the change in photoconductivity is caused by a change in the degree of disorder of amorphous inclusions. It was assumed that the semiconductor structure is dominated by cylindrical inclusions and the degree of sample disorder γ varies in the range from 0.040 to 0.065. That is, approximately 5 % of amorphous inclusions in the volume of the crystalline structure. The paper presents the results of calculations of changes in photoconductivity depending on the degree of disorder of the semiconductor structure. The results are in good agreement with obtained experimental data on amorphous-crystalline structures formed as a result of irradiation by γ-quanta. The photoconductivity of semiconductor samples irradiated with gamma rays was studied by microwave photomodulation methods using a resonator measuring transducer. [ABSTRACT FROM AUTHOR]

This paper presents a multifunctional tuneable wideband metasurface absorber based on phase-changing Vanadium dioxide (VO2). The 'quad isotropic VO2 circular sectors' are constructed on amorphous silicon dioxide (SiO2), backed with 0.2 µm-thick gold layer to design the proposed absorber. This novel wideband tunable structure can independently be used as a reflector and absorber as an EMI shield; hence, this multi-functionality in a single structure proves novel and unique in the terahertz frequency range. This unit cell offers a bandwidth of 3.5 THz with more than 90% of absorptivity under normal wave incidence. The equivalent circuit model, surface currents, and field distributions are further investigated to provide a better understanding of structural evolution. Moreover, a wideband absorption has been observed up to the 60° incident angle for both the transverse modes, showing a polarization-insensitive behavior due to the symmetricity in the structure. The parametric study explores, optimizes, and demonstrates various other main characteristics and parameters of the proposed absorber. The novel structure offers shielding effectiveness (SE) higher than 40 dB throughout the frequency band under both normal and oblique incidence. This outstanding performance makes it a strong contender for EMI-EMC applications. Furthermore, it shows great potential in the field of terahertz technology, such as terahertz imagers, detectors, sensors, and other wideband applications. [ABSTRACT FROM AUTHOR]

Scalable wet high-energy ball milling was used to refine commercial micro-silicon (Si) with water and ethanol as process control agents (PCA). After grinding, the original particle size of 15 microns was reduced to approximately 1 micron for both PCAs. The sample with water as PCA produced more amorphous silicon oxide on the surface of Si particles compared to ethanol, resulting in relatively inferior electrochemical performance. This is attributed to the fact that the water-milling-induced amorphous layer comprises a significant portion of high-valence Si than the ethanol-milling-induced surface layer. Various silicon powders ground with ethanol at different ratios (e.g., 1:3, 1:4, 1:9, and 1:12) were evaluated to establish process–performance relationships. The ball-milled Si powders with a silicon-to-ethanol ratio of 1:9 showed the best electrochemical performance, displaying an initial coulombic efficiency of about 90% and a reversible specific capacity of 3000 mA h/g for the first cycle. After 55 cycles, the reversible specific capacity was maintained at 2200 mA h/g at 0.105 A/g with a corresponding retention rate of 86%, showing good cycling stability. This amorphous shell layer structure introduced through the in situ surface during the grinding process played a role in boosting the electrochemical performance of the micro-silicon anode. In addition, the amorphous shell formed by SiOx on the milled micro-Si surface and its effect on the electrochemical performance are discussed in this paper. [ABSTRACT FROM AUTHOR]

In this paper, we describe Raman spectroscopic study for evaluating the influence of vacuum annealing on the surface modification of the focused ion beam (FIB) induced damaged layer on a single crystalline Si (c-Si) substrate. The damaged layer consisting of amorphous silicon (a-Si) with implanted Ga ions is formed after irradiating FIB onto the c-Si surface. After vacuum annealing at 700 °C for 10 s, the Raman spectrum peak of poly crystalline Si (p-Si) appears. With increasing annealing time, the spectral parameters, peak shift, peak intensity, and full width at half maximum (FWHM), for p-Si and c-Si change. Through the comparison between the phase fraction of a-Si, p-Si, and c-Si in the FIB damaged layer and the mechanical properties of the FIB-processed Si nanowires obtained in the quasistatic tensile testing, a recovery of the damaged layer by annealing is discussed. [ABSTRACT FROM AUTHOR]

Coal fly ash is regarded as a potential alternative source of rare-earth elements and has gained much attention over the past few years. However, the majority of rare-earth elements in coal fly ash are entrapped in the glassy phase, which makes the recovery of rare-earth elements from coal fly ash extremely challenging. In this paper, two pre-treatments (mechanical grinding and alkali solution treatment) were conducted to enhance the leaching recovery of rare-earth elements from coal fly ash. The best recovery of rare-earth elements by acid leaching after grinding is 79.19% at the optimal conditions. That is due to the increase of surface area, resulting in more rare-earth elements exposed from the glass phase and increase the rate of leaching. The highest rare-earth element recovery gained by acid leaching after alkali pre-treatment is 95.50% in the paper. Alkali solution destroyed the glassy aluminosilicate spheres (such as metal oxide, amorphous silicon in amorphous silica-aluminosilicate) of coal fly ash more efficiently, making it more solvable in hydrochloric acid. This research has focussed on grinding and alkali pre-treatment to provide a theoretical foundation and technology support to the extraction of rare-earth elements from coal fly ash. [ABSTRACT FROM AUTHOR]

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In contrast to the conventional planar p-i-n photodiode and a metal-semiconductor-metal photodetector, the 3-D dual-gate photosensitive thin-film transistor (TFT) architectures presented here attain excellent photoresponse characteristics. Operating the device in the subthreshold regime further boosts the photoconductive gain as a result of light-induced decrease in the threshold voltage. This paper presents design considerations along with a performance comparison between 3-D photosensitive TFTs that have π- and FIN-shaped channels and conventional TFT with a planar channel. Our paper shows that the π-shaped structure tends to have a higher sensitivity while the FIN-shaped counterpart is more responsive with wider dynamic range. For both structures, a measured photoconductive gain of 104~106% is obtained with spectral responsivity ranging from near UV to near IR, and the photoresponse time in the range of tens of milliseconds. The 3-D dual-gate photosensitive TFT architecture appears to be very promising for large-area, low-level UV, visible, and IR detection applications. [ABSTRACT FROM AUTHOR]

When fixed abrasive wire saw is used to cut polysilicon, free SiC abrasives are added into the cutting coolant to form the fixed and free abrasive combined wire sawing process, so as to impact and roll the as-sawn wafer surface to remove the ductile amorphous silicon layer. Then, the as-sawn wafer can be textured by acid etching technology. The movement characteristics of free abrasives in sawing area directly affect their lapping behavior and the morphology generation of as-sawn wafer surface. In this paper, the flow field characteristics of cutting coolant and the movement characteristics of free SiC abrasives in the sawing area were studied, when using an abrasive groups interval distribution diamond wire for sawing. A three-dimensional model of cutting coolant in sawing area was established. Based on FLUENT, the influences of wire speed, feed speed, wire pretensioning force, viscosity of cutting coolant and wire surface structure parameters on the concentration peak position of free SiC abrasives in the cutting coolant along the wire axial direction were analyzed. The results show that the concentration peak of free abrasives will gradually shift to both sides along the circumferential direction of the wire in the sawing area. The deflection angle and width angle of free abrasives concentration peak are only related to the length of the bare wire area, and decrease with the increase of its length. Comprehensively considering the hydrodynamic pressure effect in the bare wire area, reducing the wire speed and tension, and increasing the feed speed and cutting coolant viscosity are conducive to enhance the lapping effect of free SiC abrasives on the as-sawn wafer surface. The change of wire structure parameters has no regular effect on the lapping behavior of free SiC abrasives in the bare wire area. [ABSTRACT FROM AUTHOR]

A photosensitive TFT sensor called bias TFT fabricated using simple amorphous silicon process in this paper. The photosensitive current of bias TFT is linearly related to the brightness of the top light source and inversely proportional to the size of the bias region. The photosensitivity current can be up to 10E‐8 amperes under 100 nits illumination. Among four shapes of bias TFTs, L‐type TFTs have the highest photo current. [ABSTRACT FROM AUTHOR]

In this paper, we present the development of a dual‐gate (DG) architecture for hydrogenated amorphous silicon thin film transistors (a‐Si:H TFTs). The aim is to address the challenges of low on‐state current (Ion) and light‐induced degradation in traditional single‐gate (SG) TFTs. The experimental results demonstrate that the DG‐TFT exhibits significantly higher Ion compared to the SG‐TFT, and the improvement depends on the thickness of the top gate insulator. Additionally, the threshold voltage (Vth) can be adjusted by applying the top gate voltage, allowing for a full‐ swing modulation coefficient of approximately 0.2. To ensure long‐term stability, a light‐blocking layer has been incorporated as the top gate electrode, enabling the DG‐ TFT to maintain its initial properties even under intense illumination conditions of up to 28,000 nits. [ABSTRACT FROM AUTHOR]

In spot beam laser annealing, fiber laser and the polygon scanner‐based optical system play a key role by precisely controlling the laser spot position and linear velocities. Key parameters of the laser crystallization are laser power, spot overlap and line overlap. AFM, Raman, and SEM analyzes are used to evaluate polysilicon crystallization state, optimize process parameters, and understand spot beam annealing mechanism. This paper presents the spot beam annealing system configuration and experimental results for low‐temperature poly‐silicon fabrication. [ABSTRACT FROM AUTHOR]

An optical type touch‐input flat panel is designed. The driving system is based on the passive pixel sensor (PPS) array with amorphous silicon (a‐Si) TFT technology. The embedded sensing structure of the optical sensor is using the a‐Si TFT phototransistor and four‐mask process architecture technology. This paper presents a primary optical pixel sensor circuit that utilizes hydrogenated amorphous silicon photo‐transistor sensor. The a‐Si TFT phototransistor sensor is high reliability by using Multi‐N+ layer in the a‐Si TFT structure. [ABSTRACT FROM AUTHOR]

The commercial applications of silicon nanomaterials as anode in lithium-ion batteries must solve two important problems, namely low expansion and long-term cycle stability. The former is related to nano-silicon structure, while the latter depends on silicon/carbon composite structure and preparation process. In order to suppress volume expansion appeared during lithiation, this paper selects a kind of silicon nanoparticles (SiNPs) with a high degree of amorphization (81.9%), and designs a stable silicon/carbon composite material structure. Inside this structure, graphite nanoflakes (GNFs) with high specific surface are used as the skeleton, which can provide enough surface area for SiNPs to adhere and avoid the local accumulation of SiNPs. Outside this structure is uniformly coated with a layer of amorphous carbon. Raman and x-ray diffraction results show that after the high-temperature carbonization, the nano-silicon in the composite material still maintains a high degree of amorphization (67.1%) and the average crystallite size of Si has only increased from 3.7 to 9.5 nm. The initial Coulombic efficiency and reversible specific capacity of the composite material are 86.7% and 1374.8 mAh g−1, respectively. After mixing with commercial graphite, the initial Coulombic efficiency and reversible specific capacity are 93.7% and 426.4 mAh g−1, respectively. LiNi0.8Co0.1Mn0.1O2 (NCM811) is used as the cathode to produce a soft-pack battery. After 900 cycles at room temperature, the capacity remains 86.2%. The silicon/carbon anode material reported in this paper is of great potential for commercialization. [ABSTRACT FROM AUTHOR]

In recent years, researchers have placed great importance on the use of silicon (Si)-related materials as efficient light sources for the purpose of realizing Si-based monolithic optoelectronic integration. Previous works were mostly focused on Si nanostructured materials, and, so far, exciting results from Si-based compounds are still lacking. In this paper, we have systematically demonstrated the high photoluminescence external quantum efficiency (PL EQE) and internal quantum efficiency (PL IQE) of amorphous silicon oxynitride (a-SiNxOy) systems. Within an integration sphere, we directly measured the PL EQE values of a-SiNxOy, which ranged from approximately 2% to 10% in the visible range at room temperature. Then, we calculated the related PL IQE through temperature-dependent PL measurements. The obtained PL IQE values (~84% at 480 nm emission peak wavelength) were very high compared with those of reported Si-based luminescent thin films. We also calculated the temperature-dependent PL EQE values of a-SiNxOy systems, and discussed the related PL mechanisms. [ABSTRACT FROM AUTHOR]

The metaheuristic algorithms and their hybridization have been utilized successfully in the past to extract the parameters of photovoltaic (PV) cells and panels. The novelty of the paper consists of proposing the black widow optimization algorithm (BWOA) for the first time to identify the parameters of the two photovoltaic cells RTC France, amorphous silicon (aSi), and two photovoltaic panels PWP201, PVM 752 GaAs. The single-diode model (SDM) and double-diode model (DDM) for analyzing the PVs are considered. The performance of the BWOA is verified using four statistical tests: the root mean square error, which is the primary tool, the mean relative error, the mean bias error, and the coefficient of determination. The research results of this study are as follows: BWOA gave the same results, or very slightly better, for RTC and PWP201 for SDM in comparison with the best algorithms from the specialized literature; for all the other cases, BWOA has substantially better results, especially for PVM 752 GaAs, where the improvements in RMSE are: 16.5%, for PWP201: 6.25%, and for aSi: 5.3%, all for the DDM; the computing time is around 2 s, which is one of the lowest durations. A consistent study is made to optimize the accuracy and computational time in function of the number of iterations and population. [ABSTRACT FROM AUTHOR]

Broadband optical absorbers are increasingly in demand in various applications, including solar cells and radiative cooling systems. Among various types of structures, absorbers based on metamaterial structures have attracted much attention. However, they generally suffer from the issues of narrow bandwidth, high-cost fabrication, and high sensitivity to polarization changes. This paper presents a broadband, polarization-independent metamaterial absorber working in both infrared and visible frequency regimes. This structure is composed of a continuous phase-change material film ( Ge 2 Sb 2 Te 5 ) separated between two thin spacer layers of SiO 2 , and an array of amorphous Silicon particles located on the top of the structure. The proposed device was shown to exhibit remarkable absorptivity (more than 90 percent) within a broad range of frequencies starting from 250 to 1050 THz. In addition, thanks to the structural symmetry, the strong absorbance shows a considerable overlap between transverse magnetic (TM) and transverse electric (TE) modes over an extensive range of incident angles. The designing procedure for this absorber can be used as a guideline for designing similar metamaterial absorbers in any desirable frequency band. [ABSTRACT FROM AUTHOR]

The threshold voltage behavior of TFTs is an important indicator of device stability. In this paper, the effects of silicon nitride content, film thickness, and structure of the gate insulating layer of amorphous silicon TFTs on device stability are investigated. The study reproduces the abnormal turnaround phenomenon of amorphous silicon TFT threshold voltage. We optimized the device conditions with high stability. Applying the optimized device conditions, we developed a 55‐inch 4K resolution LCD product with a brightness of 4000nits. Its performance is excellent in 3000hrs accelerated aging test. [ABSTRACT FROM AUTHOR]

Herein, nanocomposites made of Ni nanoparticles in situ distributed in an amorphous silicon nitride (Ni/a-Si3N4) matrix, on the one hand, and within an amorphous silicon dioxide (Ni/a-SiO2) matrix, on the other hand, were synthesized from the same Ni-modified polysilazane precursor. In both compounds, the Ni/Si atomic ratio (0.06–0.07), average Ni nanocrystallite size (7.0–7.6 nm) and micro/mesoporosity of the matrix were rigorously fixed. Hydrogen (H2)-temperature-programmed desorption (TPD) profile analysis revealed that the activation energy for H2 desorption at about 100–130 °C evaluated for the Ni/a-Si3N4 sample (47.4 kJ mol−1) was lower than that for the Ni/a-SiO2 sample (68.0 kJ mol−1). Mechanistic study with X-ray photoelectron spectroscopy (XPS) analysis and density functional theory (DFT) calculations revealed that, at Ni nanoparticle/matrix heterointerfaces, Ni becomes more covalently bonded to N atoms in the a-Si3N4 matrix compared to O atoms in the a-SiO2 matrix. Therefore, based on experimental and theoretical studies, we elucidated that nickel–nitrogen (Ni–N) interactions at the heterointerface lead to remarkable Ni d band broadening and downshifting of the d band center relative to those generated by Ni–oxygen (Ni–O) interactions at the heterointerface. This facilitates H2 desorption, as experimentally observed in the Ni/a-Si3N4 sample. [ABSTRACT FROM AUTHOR]

The paper proposes the use of diamond–carbide–silicon composite „Skeleton"® coated with amorphous silicon as substrates for multilayer X-ray mirrors for powerful synchrotron radiation sources (3+ and 4th generation). The surfaces with the following parameters were obtained using standard deep polishing methods: flatness at the level of RMS90% = 54.2 nm; effective roughness σeff ~ 1.0 nm; high-frequency roughness σ2 × 2 ~ 0.1 nm. [ABSTRACT FROM AUTHOR]

This paper presents a Computer‐aided design (CAD) model for a‐IGZO thin film transistors (TFTs) by adapting SPICE level‐61 RPI a‐Si: H (Hydrogenated Amorphous Silicon) TFT model and level‐62 RPI Poly‐Si (Poly Silicon) TFT model. This work provides a complete understanding of SPICE level‐61 and 62 model parameters, which must be tuned for a‐IGZO TFT simulation. The adapted SPICE models of level‐61 and level‐62 could model all regions of operation of the TFT, that is, above‐threshold and below‐threshold regions. Adapted RPI poly‐Si model also shows the kink effect in ZnO thin film transistors (TFTs) due to the recombination of electron–hole pairs in the channel via boundary trap states present in the poly‐Si TFTs thereby increasing the drain current in the transistors above pinch‐off region. The extracted performance parameters of the adapted models were found to be contiguous with experimental results. The maximum deviation in the subthreshold slope is approximately 5 mV/decade for level‐61 a‐Si TFT, and for level‐62 poly‐Si TFT, deviation in the subthreshold slope is even less, that is, 0.2 mV/decade. The experimental and simulated characteristics, extracted on‐to‐off ratio, negative bias reverse saturation current, and threshold voltage were almost similar. However, an average deviation of 2.4% and 2.27% was observed in the output characteristics of the adapted level‐61 and level‐62 models, respectively. [ABSTRACT FROM AUTHOR]

Hydrogenated amorphous silicon nitride is useful as an anti-reflection coating on solar cells. The addition of hydrogen atoms to amorphous silicon nitride can reduce the dangling bonds that exist on the surface. The objective of this paper is to clarify on the behavior of hydrogen atoms absorbed in silicon nitride during the hydrogenation process at various temperatures. We investigate, in particular, the silicon and hydrogen bonds that are formed by the transfer of electrons from hydrogen to silicon to form Si 1 − , Si 2 − , Si 3 − , and Si 4 − ions. The conversion of Si 1 − ions into Si 2 − ions and then also into Si 3 − and Si 4 − occurs during enhancement of the hydrogen atoms absorbed. Hydrogenated amorphous silicon nitride was stabilized through the passivation of dangling bonds of silicon atoms and nitrogen atoms by the absorbed hydrogen atoms. The passivation was indicated by enhancement of over-coordinated silicon and nitrogen atoms as well as the reduction of under-coordinated silicon and nitrogen atoms. It was found that the thermal energy from high hydrogenation temperature was primarily used by hydrogen atoms to diffuse more and to penetrate deeper into silicon nitride rather than being used for the ionization of silicon atoms. Finally, we stress that these reactive molecular dynamic simulations have led to substantial progress in understanding how hydrogen atoms interact with amorphous silicon nitride during hydrogenation. [ABSTRACT FROM AUTHOR]

The modeling and analysis of recombination properties is one of the critical aspects in the design and development of high efficiency amorphous silicon (a-Si)/crystalline silicon (c-Si) heterostructure solar cell (SH-SC). In this paper, we have developed a recombination model pertinent for a-Si/c-Si SH-SC. Based on the model, an analytical expression for the relationship between effective carrier lifetime ( \tau \mathrm {eff} ) and excess carrier concentration ( \Delta n ), commonly termed as lifetime curve, is derived and the results are validated with the experimental data. The results show that the inverse of \tau \mathrm {eff} , after correcting for the contributions of Auger and radiative recombination in silicon, when plotted as a function of \Delta n$ , shows a linear characteristic, with each of the slope and the intercept, providing definitive details about the recombination processes occurring in the device. [ABSTRACT FROM PUBLISHER]

This paper presents an innovative multifunctional wideband conformal metasurface structure using phase-changing vanadium dioxide. It consists of “quad dual-connected arrows-shaped VO2 resonators” on an amorphous silicon dioxide (SiO2) substrate backed with a 0.2-µm-thick gold layer. This unique design functions as a reflector and absorber offering a novel contribution in the terahertz frequency range. Each unit cell covers a 6-THz bandwidth from 5.6 to 11.6 THz with more than 90% absorptivity and reflectivity. For deeper insight, the paper also explores its circuit model, surface currents, and field distributions. Furthermore, this wideband absorber maintains its performance at incident angles up to 55°, showing polarization-insensitive behavior. The simulated absorptivity aligns well with the absorptivity extracted using an equivalent circuit model (ECM). Its outstanding performance makes it suitable for electromagnetic interference-EMC, biomedical, and stealth applications. [ABSTRACT FROM AUTHOR]

In this paper, a solar cell with amorphous silicon (a-Si) passivation that uses transition metal oxides (TMOs) for charge carrier collection has been modeled and analyzed for its performance. Charge carrier selection has been incorporated through selective band alignment provided by NiO and TiO2 TMOs for electrons and holes, respectively. The presence of a-Si interfacial layers for defect passivation prevents carrier loss due to high interface state densities at the Si/TMO interfaces. This structure is a potential candidate for high-efficiency solar cells (>25%) with a realistic approach towards the solution of high defect density. Optical analysis of the proposed structure has been done to analyze the amount of light entering the silicon and capable of generating electron–hole pairs. The amount of light lost has also been quantified into reflection loss, parasitic absorption, and back metal absorption. Impact of surface passivation quality and doping of NiO and TiO2 on its performance has been analyzed through the detailed device simulations. This provides a realistic pathway for engineering of passivation quality and doping of metal oxides for improved performance. [ABSTRACT FROM PUBLISHER]

We describe organic thin‐film transistor (OTFT) demonstration by integrating existing photolithographic technology with inkjet printing, eliminating the need for dry etching and significantly reducing material consumption and the number of manufacturing processes, making OTFTs suitable for mass production. OTFTs fabricated this way demonstrate performance superior to that of amorphous silicon. [ABSTRACT FROM AUTHOR]

In this review paper, we highlight about the generations and types of solar cells. The development in solar cells have seen a rapid advancement in the efficiency and quality of various materials, in the recent years. Moreover, this paper elaborates about the dye-sensitized, perovskites, multi-junction solar cells and also the latest and future of solar cells that is organic and polymer solar cells. The objective of this paper is to introduce the solar cells and analyzing the performance of various solar cells. [ABSTRACT FROM AUTHOR]

Summary: Long‐term energy production of photovoltaic (PV) systems is predicted and evaluated using a degradation rate analysis. It is one of the most important factors to consider before investing in PV power plants since it indicates the system's dependability and, hence, profitability. This paper examines the degradation rates of three different PV module technologies in a mountain/cold region, over a 5‐year period; including monocrystalline silicon (mono‐Si), polycrystalline silicon (poly‐Si), and amorphous silicon (a‐Si). This study has been performed using different statistical techniques such as classical and seasonal decomposition (CSD), seasonal and trend decomposition using loess (STL), Holt winters (HW), and linear regression (LR). According to the obtained results, a‐Si modules have the highest degradation rate with values varying between 1.12 and 1.17%/year, followed by mono‐Si (0.69–0.98%/year) and poly‐Si (0.11–0.75%/year) technology respectively. This research included an economic analysis to determine the Levelized Cost of Electricity (LCOE) of the three investigated systems. The findings show that crystalline technologies (poly‐Si and mono‐Si) are more cost‐effective than a‐Si, with an LCOE of 0.099 USD/kWh, 0.108 USD/kWh, and 0.138 USD/KWh respectively. [ABSTRACT FROM AUTHOR]

This paper evaluates the mechanical properties of amorphous silicon carbon nitride (a-SiC x N y ) films with different atomic ratios via molecular dynamics simulation. The Si-C-N ternary amorphous model is constructed using ReaxFF potential and melt-quenching method. The results demonstrate that the density range of constructed model spans a wide range of densities (2.247–2.831 g/cm3). The short- and medium-range order of the constructed a-SiC x N y structures show a good correlation with the experimental observations. Based on the structural feasibility, the elastoplastic performance is analyzed. There is significant ductility during the uniaxial tension process of a-SiC x N y , except for Si(CN 2 ) 2 . The calculated elastic modulus ranges from 206.80 GPa to 393.58 GPa, close to the experimental values of coating films. In addition, the elastic modulus of a-SiC x N y does not change monotonically with the carbon or silicon content but is related to the atomic ratio. This article provides an understanding of the chemical composition dependence of the mechanical properties of amorphous compounds at the molecular level. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the thermostructural properties of a type of silicon-based nanomaterials, which we refer to as SiC@Si nanocomposites, formed by SiC crystalline nanoparticles (with the cubic phase), embedded within an amorphous Si matrix. We have followed an in silico approach to characterize the mechanical and thermal behaviour of these materials, by calculating the elastic constants, uniaxial stress-strain curves, coefficients of thermal expansion, and specific heats, at different temperatures, using interatomic potential calculations. The results obtained from our simulations suggest that this type of material presents enhanced thermal resistance features, making it suitable to be used in devices subjected to big temperature changes, such as heat sinks in micro and nanoelectronics, solar energy harvesters at high temperatures, power electronics, or in other applications in which good thermomechanical properties are required. [ABSTRACT FROM AUTHOR]