Material: Soft and flexible polymer semiconductor. Photonic topological phase transition. Solving the mystery of the surface structure of aluminum oxide.
Soft and flexible polymer semiconductor
Materials scientists at Stanford University used a specialized electron microscope, the cryo-electron microscope (Cryo 4D-STEM), to investigate the microstructure of soft semiconductors that could lead to a new generation of electronics.
Organic mixed ionic and electronic conductors (OMIECs) are soft and flexible polymeric semiconductors with promising electrochemical qualities. A liquid electrolyte is injected between the layers of OMIEC polymer, much like water in a car battery. An electrolyte is a medium in which ions move between the positive and negative electrodes to produce an electric current.
“When the OMIEC polymer is immersed in a liquid electrolyte, it expands like an accordion, but retains its electronic functionality,” said Hong Se and Vivian W.M. Lim, professors in the College of Engineering and senior authors of the paper. Alberto Saleo said in an article. release. “We found that long molecular chains in polymeric materials can stretch and bend gently to create continuous paths, even when the electrolyte expands the material by 300%.” (1)
Photonic topological phase transition
Researchers from NTT Corporation (NTT) and the Tokyo Institute of Technology have used a new hybrid nanostructure consisting of a phase-change material and a semiconductor nanostructure to realize photonic topological phase transition through material phase transition and a reconfigurable method. Phase transition of materials at .
According to the release, “This result paves the way for a new field of research that combines material phase transitions with photonic-topological phase transitions, and provides reconfigurable and reconfigurable materials that may lead to new optical information processing technologies. “It holds promise for functional photonic integrated circuits.”
“To date, many studies have been conducted to manipulate photonic topological properties in various ways, but due to the difficulty of band inversion, no research has achieved photonic topological phase transition.” (2)
Solving the mystery of the surface structure of aluminum oxide
Scientists from the Vienna University of Technology and the University of Vienna have revealed the detailed structure of aluminum oxide surfaces. Aluminum oxide is one of the best insulators used in electronic components, as a support material for catalysts, or as a chemically resistant ceramic.
The strong insulating properties of alumina have hindered experimental studies. The surface structure has remained a mystery for more than 50 years, and in 1997 it was listed as one of the “three great mysteries of surface science.” The research team used non-contact atomic force microscopy (ncAFM) to analyze the surface structure.
“In ncAFM images, we can see the positions of atoms, but not their chemical identity,” Johanna Hütner, who conducted the experiment, said in a release. “We overcame the lack of chemical sensitivity by precisely controlling the tip. By placing a single oxygen atom at the apex of the tip, we were able to distinguish between oxygen and aluminum atoms on the surface. The oxygen atoms at the tip are repelled from other oxygen atoms on the surface and attracted to aluminum atoms on the Al2O3 surface.By mapping the local repulsive or attractive forces, we directly visualize the chemical identity of each surface atom. I was able to.”
References
(1) Tsarfati, Y., Bustillo, KC, Savitzky, BH, et al. Hierarchical structure of organic mixed ionic electronic conductors and their evolution in water. nut. meter. (2024). https://doi.org/10.1038/s41563-024-02016-6
(2) Takahiro Uemura et al., Photonic topological phase transition induced by material phase transition, Sci. Adv.10, eadp7779 (2024). https://www.science.org/doi/10.1126/sciadv.adp7779
(3) Johanna I. Hütner et al., Stoichiometric reconstruction of Al2O3(0001) surfaces. Science 385, 1241-1244(2024). https://www.science.org/doi/10.1126/science.adq4744
Liz Allan
(All posts)
Liz Allan is an associate editor at Semiconductor Engineering.
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