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Impact of Post-Deposition Recrystallization by Alkali Fluorides on Cu(In,Ga)Se2Thin-Film Materials and Solar Cells
摘要: Using thermal evaporation, Cu(In,Ga)Se2 (CIGS) layers were deposited at low temperature (350 °C) and high rate (10 μm/h) using a single stage process. They were then recrystallized using a variety of alkali fluorides: NaF, KF, RbF and CsF. To ensure that the substrate would not influence the study (via alkali diffusion), the samples were deposited on silicon wafers. The chemical, physical and electrical properties of the films were then characterized, demonstrating that all alkali fluorides behave as fluxing agents to enhance recrystallization and conductivity, and induce a (112) preferential orientation. Secondary ion mass spectrometry analysis showed that no modification of the elements' distribution occurs because of recrystallization. Solar cells were also fabricated and characterized, indicating that NaF can double the efficiency of solar cells compared to the as-deposited layers. This enhancement is accompanied by the disappearance of a rollover, voltage dependent current collection and shunt from the current density-voltage curves. However, even for the best recrystallization, the current is still limited to 28 mA/cm2, indicating that only a portion (0.75 μm) of the full device (2 μm) is activated.
关键词: Recrystallization,Copper indium gallium selenide,Alkali-fluorides,Solar cells
更新于2025-09-16 10:30:52
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Recrystallization and activation of ultra-high-dose phosphorus-implanted silicon using multi-pulse nanosecond laser annealing
摘要: Highly phosphorus-doped silicon source/drains are investigated to improve the performance of N-type metal-oxide-semiconductor field-effect transistors by decreasing their resistance and imparting strain to their channels. To find effective high temperature annealing for the activation of phosphorus in the source/drains, we apply single- and multi-pulse nanosecond laser annealing on highly phosphorus-doped silicon. The microstructure, strain, and electrical properties of highly phosphorus-doped silicon before and after laser annealing are analyzed. Our results demonstrate that the defects in both the recrystallized silicon and the end of range are decreased with 600 mJ cm?2 10-pulse annealing while considerable increase in phosphorus activation is achieved.
关键词: nanosecond laser annealing,strain engineering,activation,phosphorus-doped silicon,recrystallization
更新于2025-09-16 10:30:52
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AIP Conference Proceedings [AIP Publishing 15th International Conference on Concentrator Photovoltaic Systems (CPV-15) - Fes, Morocco (25–27 March 2019)] 15th International Conference on Concentrator Photovoltaic Systems (CPV-15) - Zone melting recrystallization of microcrystalline silicon ribbons obtained by chemical vapor deposition
摘要: We present the results achieved with an optical zone melting recrystallization (ZMR) system, which concentrates the radiation of two halogen lamps on the surface of a microcrystalline silicon (μc-Si) ribbon sample, creating a long, 2 mm width molten region (~1414o C). μc-Si ribbon samples measuring up to 25×100 mm2 were previously obtained using an inline optical chemical vapor deposition (CVD) system, that grows silicon layers on top of a silicon dust substrate. Inside the ZMR system, the μc-Si ribbon sample is recrystallized in an argon atmosphere and using a step motor to pull the ribbon at a constant speed between 1 to 6 mm/min, the molten zone travels along the ribbon, recrystallizing the whole sample into a multi-crystalline silicon (mc-Si) ribbon, with an average crystal size in the [1; 10] mm range. It was observed that the physical characteristics of the μc-Si ribbon, like powder substrate incorporation, porosity, thickness, powder grain size used as substrate in the CVD step, have a crucial influence on the recrystallization process and on the electrical properties of the mc-Si ribbon obtained after the ZMR process. Lifetime measurements performed on the recrystallized samples suggest that improvements regarding crystalline quality and possible presence of impurities need to be addressed.
关键词: microcrystalline silicon,solar cells,Zone melting recrystallization,multi-crystalline silicon,chemical vapor deposition
更新于2025-09-12 10:27:22
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109 Evaluation of the Efficacy and Safety of Fractional Picosecond 1064-nm Laser Treatment for Skin Rejuvenation
摘要: Gold (Au) colloids are becoming ubiquitous across biomedical engineering, solar energy conversion, and nano-optics. Such universality has originated from the exotic plasmonic effect of Au colloids (i.e., localized surface plasmon resonance (LSPRs)) in conjunction with the versatile access to their synthetic routes. Herein, we introduce a previously undiscovered usage of Au colloids for advancing cryoprotectants with significant ice recrystallization inhibition (IRI). Oligopeptides inspired by the antifreeze protein (AFP) and antifreeze glycoprotein (AFGP) are attached onto the surface of well-defined Au colloids with the same sizes but different shapes. These AF(G)P-inspired Au colloids can directly adsorb onto a growing ice crystal via the synergistic interplay between hydrogen bonding and hydrophobic groups, in stark contrast to their bare Au counterparts. Dark-field optical microscopy analyses, benefitting from LSPR, allow us to individually trace the in situ movement of the antifreezing Au colloids during ice growth/recrystallization and clearly evidence their direct adsorption onto the growing ice crystal, which is consistent with theoretical predictions. With the assistance of molecular dynamics (MD) simulations, we evidently attribute the IRI of AF(G)P-inspired Au colloids to the Kelvin effect. We also exploit the IRI dependence on the Au colloidal shapes; indeed, the facet contacts between ice and Au colloids can be better than the point-like counterparts in terms of IRI. The design principles and predictive theory outlined in this work will be of broad interest not only for the fundamental exploration of the inhibition of ice growth but also for enriching the application of Au colloids.
关键词: gold colloids,antifreezing proteins,dark-field microspectroscopy,oligopeptides,Ice recrystallization inhibition
更新于2025-09-11 14:15:04
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Study of Grain Boundary Character || Control the Metal Grain Boundary Recrystallization Evolution by the Laser Radiation Electric Field Strength Direction Under Cyclic Thermal Loading
摘要: The spatial grating formation at metal surface under the linear polarized laser radiation action is briefly considered. The spatial grating periods are well described in framework of universal polariton model (UPM) and are well-defined physical quantities. The production of new-type gratings (quasi-gratings) at laser power densities lower than the metal melting threshold with power-dependent typical spatial scale and polarization-dependent orientation are discovered. The regularities of quasi-grating production are experimentally studied. The physical model of quasi-grating formation explaining the anisotropic character of metal recrystallization is suggested. The anisotropy is caused by the directed electron flux interaction with grain boundaries. The electron flux results from the drag effect of electrons by surface plasmon polaritons (SPPs). SPPs are excited by incident laser radiation on the surface irregularities including the grain boundaries. The volume analog of considered effect is the electroplastic one, and some of its regularities are considered.
关键词: grain boundary movement,laser radiation,electrons drag by surface plasmon polaritons,metal,electroplastic effect,surface plasmon polaritons,linear polarization,anisotropic recrystallization
更新于2025-09-11 14:15:04
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Design principle of all-inorganic halide perovskite-related nanocrystals
摘要: All-inorganic halide perovskite (AIHP)-related (e.g., CsPbBr3, Cs4PbBr6, and CsPb2Br5) nanocrystals have attracted great research interest in the recent three years, owing to their unique optical properties. However, rational structural and compositional control of these nanocrystals is still challenging, particularly using the room temperature saturated recrystallization (RTSR) method. Here, we revealed that the structure and the composition of the nanocrystals fabricated by the RTSR approach are highly dependent not only on the previously thought concentration ratio of PbBr2 and CsBr in N-dimethylformamide (DMF), but the previously neglected absolute concentration and reaction time. This is the reason why pure AIHP-related nanocrystals are usually difficult to prepare using the RTSR method. Through a series of carefully designed experiments, we obtained the evolution trend of the precipitation rate of PbBr2 and CsBr within a wide concentration range in DMF. Based on the understanding of the growth mechanism, we achieved preparation of pure or a mixture of CsPbBr3, Cs4PbBr6, and CsPb2Br5 nanocrystals through either control of the concentration of PbBr2 and CsBr or the reaction time. This study deepens our understanding of the growth mechanism of AIHP-related nanocrystals, paving the way for future engineering of nanocrystals with desired structures and compositions. These structures with desired compositions will definitely have promising applications in optical and optoelectronic devices.
关键词: nanocrystals,All-inorganic halide perovskite,room temperature saturated recrystallization,optical properties,optoelectronic devices
更新于2025-09-10 09:29:36
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Synthesis and Structural Characterizations of meso-Tetraphenyl Porphyrin
摘要: In this paper, tetraphenyl porphyrin (H2TPP) was synthesized by using pyrrole and benzaldehyde as raw materials under the catalysis of p-nitrobenzoic acid. The prepared tetraphenyl porphyrin was re-crystallized in a mixed system of methanol and methylene chloride (CH2Cl2) and the yield of tetraphenyl porphyrin is 34.2 %. Tetraphenyl porphyrin was characterized by using FTIR, UV-visible, 1H NMR and fluorescence spectrophotometer. The effects on the yield of tetraphenyl porphyrin at different volumes of dimethylbenzene as solvent were explored.
关键词: Recrystallization,Tetraphenylporphyrin,Structural characterization
更新于2025-09-10 09:29:36
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Recrystallization Phase in He-Implanted 6H-SiC
摘要: The evolution of the recrystallization phase in amorphous 6H-SiC formed by He implantation followed by thermal annealing is investigated. Microstructures of recrystallized layers in 15 keV He+ ion implanted 6H-SiC (0001) wafers are characterized by means of cross-sectional transmission electron microscopy (XTEM) and high-resolution TEM. Epitaxial recrystallization of buried amorphous layers is observed at an annealing temperature of 900°C. The recrystallization region contains a 3C-SiC structure and a 6H-SiC structure with different crystalline orientations. A high density of lattice defects is observed at the interface of different phases and in the periphery of He bubbles. With increasing annealing to 1000°C, 3C-SiC and columnar epitaxial growth 6H-SiC become unstable, instead of [0001] orientated 6H-SiC. In addition, the density of lattice defects increases slightly with increasing annealing. The possible mechanisms for explanation are also discussed.
关键词: Recrystallization,lattice defects,He-implanted 6H-SiC,annealing,TEM
更新于2025-09-09 09:28:46