Unlocking the Secrets of Crystal Plane Effect: Inspiring Breakthroughs in Semiconductor Research

2023-09-29 00:08:48
The academic community used to believe that the conductivity, optical properties and other physical and chemical properties of the same crystal should be the same. Professor Huang Xuanyi’s team from the Department of Chemistry at Tsinghua University published the theory of “crystal plane effect”, which proves that even if crystals are made of the same chemical elements, as long as they have different shapes, they will be different due to differences in the thin layers on the crystal surface and the internal lattice arrangement. electrical, optical properties and photocatalytic activity. The research results were published in the top journal “Small” and are expected to inspire innovative breakthroughs in the next generation of semiconductor research. But Huang Xuanyi discovered many years ago that cuprous oxide octahedral crystals are the most conductive, followed by cubic crystals, and rhombic dodecahedral crystals are completely non-conductive. In addition, cuprous oxide rhombic dodecahedral crystals have the best photocatalytic activity, followed by Octahedral crystals and cubic crystals do not have photocatalytic activity, and different shapes of crystals have different colors. Huang Xuanyi’s research team includes Luo Youjie (from left), associate professor of the Department of Materials at Yangming Jiaotong University, doctoral student Gao Ruicheng, in-service doctoral student Chen Pakhao of the Tsinghua Department of Chemistry, professor Huang Xuanyi, professor Chen Yijia, and associate researcher Zhuang Yujun of the National Synchrotron Radiation Research Center. Faced with these differences, many researchers did not further explore this phenomenon, but this aroused Huang Xuanyi’s curiosity, hoping to confirm this strange crystal face effect with experimental data. Huang Xuanyi hypothesized that there is a thin layer on the surface of the crystal. Due to the minimal difference in atomic positions, the lattice arrangement of the surface layer and the internal lattice change, resulting in different charge movement and light absorption effects. “It’s like lightly grilling the surface of sashimi with a flame. The appearance may look the same, but the aroma and taste will change.” Huang Xuanyi compared it. To confirm this hypothesis, Huang Xuanyi’s team used high-resolution X-rays from the National Synchrotron Radiation Center to illuminate the crystals and observed them with a high-resolution electron microscope. Sure enough, they discovered the lattice arrangement on octahedral crystals, cubic crystals, and rhombohedral twelve-sided crystals. They are all inconsistent, confirming the “crystal plane effect” theory. According to this theory, semiconductors will also produce different piezoelectric and magnetic properties. Chen Pakhao, a doctoral student in the Department of Chemistry at Tsinghua University and a research assistant at the National Synchrotron Radiation Center, explained that the light source of the Taiwan Photon Source High-Resolution Powder Diffraction Experiment Station is strong, the beam is straight and difficult to diverge, so the accuracy of the experiment is very high. He took cuprous oxide nanocrystal powder, filled it in a capillary with a diameter of only 0.3mm, and exposed it with X-rays. He found two diffraction peaks on the picture, showing that there are indeed two different lattice arrangements on the surface and inside of the crystal. Way. Huang Xuanyi believes that understanding the mechanism of the crystal face effect will enable wider applications of semiconductor materials in the future, such as using crystal faces to control charge transfer, or selecting appropriate crystal face combinations to make transistors. Huang Xuanyi thanked the National Synchrotron Radiation Research Center for its technical support, which made him believe that the hypothesis he had believed for many years was finally confirmed.More news recommendations● Tsinghua’s crystal plane effect theory is published to inspire innovative breakthroughs in the next generation of semiconductors
1695954232
#Tsinghuas #crystal #plane #effect #theory #published #inspire #innovative #breakthroughs #nextgeneration #semiconductors