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In the last few years the need and demand for utilizing clean energy resources has increased dramatically. Energy received from sun in the form of light is a sustainable, reliable and renewable energy resource. This light energy can be transformed into electricity using solar cells (SCs). Silicon was early used and still as first material for SCs fabrication. Thin film SCs are called as second generation of SC fabrication technology. Amorphous silicon (a-Si) thin film solar cell has gained considerable attention in photovoltaic research because of its ability to produce electricity at low cost. Also in the fabrication of a-Si SC less amount of Si is required. In this review article we have studied about types of a-Si SC namely hydrogenated amorphous silicon (a-Si:H) SC and hydrogenated amorphous silicon germanium(a-SiGe:H) SC. This article also reviews about various techniques adopted to improve the efficiency and performance of a-Si SC, stability issues in a-Si SC as well its recent developments.

The present article focuses on a cradle-to-grave life cycle assessment (LCA) of the most widely adopted solar photovoltaic power generation technologies, viz., mono-crystalline silicon (mono-Si), multi-crystalline silicon (multi-Si), amorphous silicon (a-Si) and cadmium telluride (CdTe) energy technologies, based on ReCiPe life cycle impact assessment method. LCA is the most powerful environmental impact assessment tool from a product perspective and ReCiPe is one of the most advanced LCA methodologies with the broadest set of mid-point impact categories. More importantly, ReCiPe combines the strengths of both mid-point-based life cycle impact assessment approach of CML-IA, and end-point-based approach of Eco-indicator 99 methods. Accordingly, the LCA results of all four solar PV technologies have been evaluated and compared based on 18 mid-point impact indicators (viz., climate change, ozone depletion, terrestrial acidification, freshwater eutrophication, marine eutrophication, human toxicity, photochemical oxidant formation, particulate matter formation, terrestrial ecotoxicity, freshwater ecotoxicity, marine ecotoxicity, ionising radiation, agricultural land occupation, urban land occupation, natural land transformation, water depletion, metal depletion and fossil depletion), 3 end-point/damage indicators (viz., human health, ecosystems and cost increases in resource extraction) and a unified single score. The overall study has been conducted based on hierarchist perspective and according to the relevant ISO standards. Final results show that the CdTe thin-film solar plant carries the least environmental life cycle impact within the four PV technologies, sequentially followed by multi-Si, a-Si and mono-Si technology.

Flexible electronics enable various technologies to be integrated into daily life and fuel the quests to develop revolutionary applications, such as artificial skins, intelligent textiles, e-skin patches, and on-skin displays. Mechanical characteristics, including the total thickness and the bending radius, are of paramount importance for physically flexible electronics. However, the limitation regarding semiconductor fabrication challenges the mechanical flexibility of thin-film electronics. Thin-Film Transistors (TFTs) are a key component in thin-film electronics that restrict the flexibility of thin-film systems. Here, we provide a brief overview of the trends of the last three decades in the physical flexibility of various semiconducting technologies, including amorphous-silicon, polycrystalline silicon, oxides, carbon nanotubes, and organics. The study demonstrates the trends of the mechanical properties, including the total thickness and the bending radius, and provides a vision for the future of flexible TFTs.

The characteristics of a hydrogenated amorphous silicon (a-Si:H) detector are presented here for monitoring in space solar flares and the evolution of strong to extreme energetic proton events. The importance and the feasibility to extend the proton measurements up to hundreds of MeV is evaluated. The a-Si:H presents an excellent radiation hardness and finds application in harsh radiation environments for medical purposes, for particle beam characterization and, as we propose here, for space weather science applications. The critical flux detection limits for X rays, electrons and protons are discussed.

This work investigates the nickel-induced crystallization (NIC) method for crystallizing hydrogenated amorphous silicon (a-Si: H) thin films on glass substrates. The a-Si: H samples are prepared using plasma-enhanced chemical vapor deposition at a temperature of 250 °C. Subsequently, thin layers of nickel are deposited on the a-Si: H films using DC magnetron sputtering. The resulting structures (Ni/a-Si: H/glass) are then subjected to annealing at 570 °C under an N 2 atmosphere. Two annealing processes are compared: one involving a prior dehydrogenation step and the other without dehydrogenation. The impact of the annealing process on the crystallization of the amorphous films is investigated using X-ray diffraction, atomic force microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. The crystallinity of the samples is confirmed by X-ray diffraction and Raman spectroscopy. The results suggest that the dehydrogenation step may not be essential for achieving crystallization in hydrogenated amorphous silicon layers.

In this study, the characteristics of phosphorus-doped hydrogenated amorphous silicon carbide prepared by radio-frequency glow discharge decomposition of a mixture of silane (SiH4), methane (CH4) and hydrogen (H2) were investigated. Molecular vibration, surface morphology, dark electrical conductivity, and activation energy were analyzed. The gas phase composition of CH4 was varied in the range of 0.40–0.95 relative to SiH4, while the molar fraction of phosphine (PH3) in the gas phase was adjusted from 2.75% to 10%. It was observed that the molar fraction of carbon (C) in the film affects its homogeneity, resulting in the formation of regions rich in silicon (Si) and amorphous silicon carbide (a-SixC1−x), as well as the formation of nc-Si clusters, leading to lower surface roughness. The variation in electrical properties concerning doping and the molar fraction of carbon is consistently explained in this study.

The microstructure factor ( R* ) of the PECVD-grown intrinsic amorphous silicon (i-a-Si:H) layer plays a crucial role in crystalline silicon (c-Si) surface passivation and charge carrier transport in silicon heterojunction (SHJ) solar cells. In this work, we have used stack of i-a-Si:H passivation layers deposited at two different temperatures to improve the c-Si surface passivation by minimizing the interface defect density at the a-Si/c-Si interface. The initial i 1 -a-Si:H layer is deposited on the c-Si at ~ 150 °C with a high R* , and the second i 2 -a-Si:H layer is deposited at 230 °C with a low R* . Ex-situ ellipsometry analysis of i-a-Si:H layers provided information related to the void fraction of the thin films due to modification in the Si–H ≥2 and Si–H bonding environment, which plays a vital role in atomic H migration towards i-a-Si:H/c-Si interface. Combining the low- and high-temperature i-a-Si:H layer stack enhanced the cell precursor passivation to ~ 2.1 ms with an implied V oc of ~ 714 mV. Furthermore, implementing the optimized thickness (2 nm + 8 nm) of the i-a-Si:H stack (with 40% void fraction in i 1 -a-Si:H layer) in the device has led to the power conversion efficiency of ~ 19.06%.

This paper presents the results of the study on the development of a methodology for the production of pure amorphous silicon dioxide containing up to 99.8 wt.% of SiO2. As a starting material, a silica gel with a moisture content of up to 55 wt.% and an SiO2/AlF3 ratio of 4 was used. The silica gel was purified using alkaline and acidic solutions in concentrations ranging from 0.1 to 25 wt.%. The analysis of the experimental data allowed to identify the most suitable purification parameters of the starting material. The initial silica gel and the reaction products were studied using the methods of X-ray fluorescence, X-ray phase analysis, electron scanning microscopy, EDS microanalysis, and particle-size analysis. Amorphous silicon dioxide obtained according to the methodology developed by the authors forms agglomerates of spherical silicon dioxide particles up to 1 μm in size. Amorphous silicon dioxide was involved in the preparation of catalyst supports in order to consider the possibility of replacing part of the expensive raw material in the form of aluminum hydroxide. In the work, the characteristics of the addition of this amorphous silicon dioxide and the supports obtained from the traditionally used raw materials were evaluated.

Implantable microelectrode arrays (MEAs) enable the recording of electrical activity of cortical neurons, allowing the development of brain-machine interfaces. However, MEAs show reduced recording capabilities under chronic conditions, prompting the development of novel MEAs that can improve long-term performance. Conventional planar, silicon-based devices and ultra-thin amorphous silicon carbide (a-SiC) MEAs were implanted in the motor cortex of female Sprague–Dawley rats, and weekly anesthetized recordings were made for 16 weeks after implantation. The spectral density and bandpower between 1 and 500 Hz of recordings were compared over the implantation period for both device types. Initially, the bandpower of the a-SiC devices and standard MEAs was comparable. However, the standard MEAs showed a consistent decline in both bandpower and power spectral density throughout the 16 weeks post-implantation, whereas the a-SiC MEAs showed substantially more stable performance. These differences in bandpower and spectral density between standard and a-SiC MEAs were statistically significant from week 6 post-implantation until the end of the study at 16 weeks. These results support the use of ultra-thin a-SiC MEAs to develop chronic, reliable brain-machine interfaces.

This work presents the formation and characterization of amorphous silicon carbide nanowires (ASCNW) for an application as CO 2 gas sensor. The preparation of the ASCNW structure required two stages, the first one consisted on the formation of Si nanowires on p-type silicon (p-Si) with low resistivity, by chemical etching assisted by a metal (Ag), where the second concerned the deposition of hydrogenated amorphous SiC thin films of on silicon nanowires (SNW), by RF magnetron sputtering, with varied thicknesses ranging between 2 and 60 nm. To study the structural and optical properties of ASCNW, different characterization techniques were used, such as scanning electron microscope (SEM) and photoluminescence (PL). The results show the formation of ASCNW with a high intensity of photoluminescence. In order to investigate the large specific surface area and great stability, the ASCNW-based structures were used as a detection device for gases, such as CO 2 . In light of the obtained results, it was found that the structure of the ASCNW presented an improved and extremely stable detection performance compared to previous results and could be promising for the construction of an efficient gas sensor device.