Electron backscatter diffraction

About: Electron backscatter diffraction is a research topic. Over the lifetime, 15184 publications have been published within this topic receiving 317847 citations. The topic is also known as: EBSD.

Direct Imaging of Cl- and Cu-Induced Short-Circuit Efficiency Changes in CdTe Solar Cells

Abstract: To achieve high-efficiency polycrystalline CdTe-based thin-film solar cells, the CdTe absorbers must go through a post-deposition CdCl2 heat treatment followed by a Cu diffusion step. To better understand the roles of each treatment with regard to improving grains, grain boundaries, and interfaces, CdTe solar cells with and without Cu diffusion and CdCl2 heat treatments are investigated using cross-sectional electron beam induced current, electron backscatter diffraction, and scanning transmission electron microscope techniques. The evolution of the cross-sectional carrier collection profile due to these treatments that cause an increase in short-circuit current and higher open-circuit voltage are identified. Additionally, an increased carrier collection in grain boundaries after either/both of these treatments is revealed. The increased current at the grain boundaries is shown to be due to the presence of a space charge region with an intrinsic carrier collection profile width of ≈350 nm. Scanning transmission electron microscope electron-energy loss spectroscopy shows a decreased Te and increased Cl concentration in grain boundaries after treatment, which causes the inversion. Furthermore, each treatment improves the overall carrier collection efficiency of the cell separately, and, therefore, the benefits realized by each treatment are shown to be independent of each other.

Evolution of twins and substructures during low strain rate hot deformation and contribution to dynamic recrystallization in alloy 617B

Abstract: Substructure and twin boundary evolution of alloy 617B during dynamic recrystallization (DRX) was investigated by optical microscope, electron backscatter diffraction (EBSD) and transmission electron microscope (TEM) technique. Simulated compression tests were carried out at different true strains in the temperature range of 1120–1210 °C with a strain rate of 0.001 s −1 . The results show that discontinuous dynamic recrystallization (DDRX) featured by original grain boundary bulging is the dominant nucleation mechanism for alloy 617B. The progressive subgrain rotation, which is a characterization of continuous dynamic recrystallization (CDRX) can be detected at the early stage of hot deformation at lower temperature, which can just be considered as an assistant mechanism. The evolution of substructure and twin boundaries have a significant effect on DRX process of alloy 617B. Twinning formation can active the DRX process by accelerating original grain boundary bulging and separation of bulging grain boundaries. The formation of twin steps resulting from twin slipping provide additional DRX nucleation locations. The effort of twins gets weaker with the increase of temperature as the DRX grain growth process associated with grain boundary area reduction gradually becomes a preferential mechanism for energy minimization. Different from previous study, the fraction of twin boundaries decrease with the increase of temperature, which can be attributed to the twin boundary accelerated prior grain growth process. Such process also results in the serious bulging of grain boundaries into adjacent grains.

Microstructure and texture evolution during accumulative roll bonding of aluminium alloy AA5086

Abstract: In the present investigation, a strongly bonded strip of an aluminium–magnesium based alloy AA5086 is successfully produced through accumulative roll bonding (ARB). A maximum of up to eight passes has been used for the purpose. Microstructural characterization using electron backscatter diffraction (EBSD) technique indicates the formation of submicron sized (∼200–300 nm) subgrains inside the layered microstructure. The material is strongly textured where individual layers possess typical FCC rolling texture components. More than three times enhancement in 0.2% proof stress (PS) has been obtained after 8 passes due to grain refinement and strain hardening.