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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Recrystallization boundary migration in the 3D heterogeneous microstructure near a hardness indent
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Localized Recrystallization of a Lithium-Metal Anode during Fast Stripping in High-Activity Liquid Electrolytes
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Ex-Situ Recrystallization of CIGS via Metal Halides
Post Deposition Treatments (PDT) have been key to improving the efficiency of CIGS solar cells. While efficiency has continued to increase, for thermal evaporation processes, high substrate temperature and low deposition rates are a necessity. For many chemical processes, chemical vapor transport techniques can be used to both purify and grow both large and pure crystalline compounds. This is often done with a halide species and temperature. Here, by using the substituent metals of CIGS in confluence with a halide, we explored the possibility to grow a CIGS layer at low temperature and fast rate while still having sufficiently high efficiency.
On the Effect of Indium Chloride Dose on the Recrystallization of Cu(In,Ga)Se 2 Thin Films and associated Devices
Cu(In,Ga)Se 2 thin films deposited by a single-stage co-evaporation process at 350 ºC on molybdenum coated soda lime glass substrate were annealed post-deposition in InCl 3 vapor. The amount of InCl 3 and Se was varied. Here, the annealing treatment was done at 450 ºC for 30 minutes. Increase in grain size was observed after the treatment in all cases by X-ray diffraction. Device performance was low, but improved slightly after KCN etching.
Analysis of Post-Deposition Recrystallization Processing via Indium Bromide of Cu(In,Ga)Se2 Thin Films
Cu(In,Ga)Se2 (CIGS) thin films were deposited at low temperature (350 °C) and high rate (10 µm/h) by a single stage process. The effect of post-deposition treatments at 400 °C and 500 °C by indium bromide vapor were studied and compared to the effect of a simple annealing under selenium. Structural, electrical, and chemical analyses demonstrate that there is a drastic difference between the different types of annealing, with the ones under indium bromide leading to much larger grains and higher conductivity. These properties are associated with a modification of the elemental profiles, specifically for gallium and sodium.
Revealing a Pathway for Low-Temperature Recrystallization in Germanium
Thermally activated annealing in semiconductors faces inherent limitations, such as dopant diffusion. Here, a nonthermal pathway is demonstrated for a complete structural restoration in predamaged germanium via ionization-induced recovery. By combining experiments and modeling, this study reveals that the energy transfer of only 2.4 keV nm −1 from incident ions to target electrons can effectively annihilate pre-existing defects and restore the original crystalline structure at room temperature. Moreover, it is revealed that the irradiation-induced crystalline-to-amorphous (c/a) transformation in Ge is reversible, a phenomenon previously considered unattainable without additional thermal energy imposed during irradiation. For partially damaged Ge, the overall damage fraction decreases exponentially with increasing fluence. Surprisingly, the recovery process in preamorphized Ge starts with defect recovery outside the amorphous layer and a shrinkage of the amorphous thickness. After this initial stage, the remaining damage decreases slowly with increasing fluence, but full restoration of the pristine state is not achieved. These differences in recovery are interpreted in the framework of structural differences in the initial defective layers that affect recovery kinetics. This study provides new insights on reversing the c/a transformation in Ge using highly-ionizing irradiation and has broad implications across materials science, radiation damage mitigation, and fabrication of Ge-based devices.
An In Situ Study of the Role of Pressure on Fe Recrystallization and Grain Growth During Thermomechanical Processing
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Selective growth of recrystallizing grains into well-characterized deformed aluminum at hardness indentation
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Recrystallization behavior and mechanical properties of Haynes 282 fabricated by wire-arc additive manufacturing with post-heat treatment
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Radiation-induced amorphization and recrystallization of hydroxyapatite nanoparticles
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Nanotwinning-assisted dynamic recrystallization at high strains and strain rates
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Nanoscale core–shell structure and recrystallization of swift heavy ion tracks in SrTiO 3
It is widely accepted that the interaction of swift heavy ions with many complex oxides is predominantly governed by the electronic energy loss that gives rise to nanoscale amorphous ion tracks along the penetration direction.
Recrystallization, melting, and erosion of dispersoid-strengthened tungsten materials during exposure to DIII-D plasmas.
Abstract not provided.