Pusan National University

报告摘要：

Growing thin films as single crystals has long been considered a highly challenging, and even impossible task from a materials science perspective. When copper is transformed into a truly two-dimensional single crystal, electrons exhibit peculiar behaviors due to the absence of diffusive scattering and the emergence of an extremely long coherence length. [1] When the surface becomes ultra-flat, electrons undergo specular reflection instead of diffusive scattering upon collision, thus preserving their coherence. The relationship between copper and oxygen also changes significantly in single-crystal copper. Traditionally, copper and oxygen are known to have a strong affinity for each other, with oxygen attacking defects. Rough copper surfaces, in particular, become prime targets for such oxygen attack.

In this presentation, I will first introduce the growth of single-crystal copper thin films [2], and discuss how such ultra-flat single-crystal surfaces influence graphene growth [3] and the specific interactions between copper surfaces and oxygen [4]. In general, conventional copper exhibits non-uniform chemical bonding with oxygen, leading to non-uniform and unattractive surface appearances. In contrast, in single-crystal copper, oxidation can be controlled vectorially, resulting in strikingly beautiful, vivid surface colors [5]. When the surface is completely defect-free and composed of ideally single-atomic-step terraces, oxidation does not occur even after long-term exposure at room temperature [4, 6]. While grain boundaries can be controlled during the early stages of thin film growth, the formation of twin boundaries appears to be an intrinsic characteristic. Understanding the mechanism of twin boundary formation is crucial for interpreting new physical properties. Moreover, developing techniques that maintain conductivity while preventing oxidation even at high temperatures above 300°C [7] will significantly advance the level of industries that utilize copper.

[1] Adv. Mater. 2403783 (2024)

[2] Nat. Commun. 14, 685 (2023)

[3] Nature Nanotech. 15, 861-867 (2020)

[4] Nature 603, 434-438 (2022)

[5] Adv. Mat. 33, 202007345 (2021)

[6] Adv. Mater. 35, 2210564 (2023)

[7] Nature Commun. 16, 1462 (2025)

报告人简介：

Prof. Se-Young Jeong earned his B.S. and M.S. in physics from Pusan National University (1977–1985), and a Dr. rer. nat.(Ph.D) in crystal physics in Germany (1990). After a year as a senior researcher at the Electronics and Telecommunications Research Institute (ETRI), he joined the Pusan National University in 1991, first in the Department of Physics and then in the Department of Optics and Mechatronics Engineering. Since February 2024, he has been a Distinguished Professor at Pusan National University, an Invited Professor at KAIST, and a Visiting Professor at Harvard Medical School.

During his period in Pusan National University, he led the Crystal Bank Research Center, spearheading research on single crystals. He also served as Vice President and Secretary General of the Korean Physical Society, as well as Editor-in-Chief of Current Applied Physics.

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邀请人：朱学涛  研究员  （9008）

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