http://repository.sungshin.ac.kr/handle/2025.oak/161 2026-05-19T14:07:25Z http://repository.sungshin.ac.kr/handle/2025.oak/8822 Title: Protocol for lateral patterning of van der Waals heterostructures using sequential chemical vapor deposition Author(s): 한혁진; 차순영; 안지훈; 진강태 Abstract: Previous work demonstrates that scalable area-selective deposition of van der Waals monolayers enables tunable design of atomically thin electronic and photonic platforms. Here, we present a protocol for lateral patterning of MoS 2025-06-19T15:00:00Z http://repository.sungshin.ac.kr/handle/2025.oak/8820 Title: Current Status of Zinc Oxide Nanopowder Manufacturing Technology for UV Filters Author(s): 홍현선 Abstract: Zinc oxide has attracted attention due to its high functionality, including chemical stability, high biocompatibility, and excellent optical properties. In particular, when the particles are nano-sized, they exhibit new characteristics, making them suitable for application in UV-filters, photo-catalysts and cosmetics. This paper provides an overview of nano zinc oxide used for UV filters, and summarizes domestic and international production technology and the industrial status of zinc oxide nano-powder. First, the concept and principle of the nano-sized zinc oxide manufacturing process is provided, and various types of manufacturing methods are analyzed, namely, wet process, dry process, and powder process. Next, the results of an analysis of the domestic sunscreen market size and company status are provided. The production processes of major domestic companies and their product characteristics, such as particle size, purity, surface treatment, and transparency of the zinc oxide powder being produced, are analyzed and provided. The characteristics of zinc oxide produced for use in sunscreens, both domestically and internationally, can be summarized as follows. Manufactured zinc oxide powder is white or transparent, and particle size typically ranges from 30 to 200 nm on average, although non-nano sized powders h 2025-05-26T15:00:00Z http://repository.sungshin.ac.kr/handle/2025.oak/8779 Title: Synthesis and luminescence characteristics of manganese-doped ZnSe quantum dots synthesized in aqueous solution through internal doping Author(s): 홍현선; 김예린; 김재형; 류현선; 송다혜 Abstract: Long-term stable manganese ion-doped ZnSe/ZnS quantum dots were prepared through an internal doping strategy. The internal doping method consisted of nucleation of MnSe core particles, exchange of manganese ions for zinc ions, and formation of an external layer of ZnSe in an aqueous solution. The internally doped Mn:ZnSe showed excellent optical properties compared with those of external doping or interfacial doping; 31% increase in photo-luminescence (PL) intensity. To optimize multiple emission peaks and color purity, varying the Mn/Zn ratio, controlling pH, and multi-step injection of Zn precursor were used. The resulting quantum dots exhibited high color purity of 96% while suppressing trap emission. The highest photo-luminescence was achieved when the molar ratio of Mn to Zn was 0.02. It was also revealed that the presence of the ZnS shell of the Mn2+-doped quantum dots enhanced the long-term stability of the quantum dots up to at least 80 days. This study implies the non-toxic and facile synthesis of Mn:ZnSe quantum dots by internal doping strategy can be an environmentally friendly and highly efficient process of color-controlled ZnSe quantum dots for biomedical imaging applications. 2025-04-30T15:00:00Z http://repository.sungshin.ac.kr/handle/2025.oak/8771 Title: Facet-Controlled Growth of Molybdenum Phosphide Single Crystals for Efficient Hydrogen Peroxide Synthesis Author(s): 한혁진; 김서현; Jeong-Hyun Kim; Bogeun Park; Hanhwi Jang; Jeong-Gyu Lee; Soonmin Yim; Jae Won Jeong; Seyoung Koo; Yeon Sik Jung; Byung-Hyun Kim; Min-Jae Choi Abstract: Transition metal phosphides (TMPs) stand out for their excellent catalytic activity, driven by metal‒phosphorus bonding that promotes electron donation, which makes them ideal for electrocatalysis applications. However, the synthesis of single-crystal TMP, which is essential for elucidating intrinsic properties, remains challenging owing to the lack of efficient methods, low yields, and lengthy processes. This study presents the synthesis of facet-controlled molybdenum phosphide (MoP) single crystals using a liquid-metal-assisted chemical vapor deposition method. By adjusting the synthesis temperature, two distinct MoP morphologies are created: nanoplates dominated by (0001) facets and pillars dominated by facets. Electrochemical evaluation reveals that the MoP pillars outperform nanoplates in the two-electron oxygen reduction reaction, achieving over 92% selectivity for H2O2 production and significantly higher kinetic current density. Long-term stability tests confirm that the MoP pillars maintain a high Faradaic efficiency (>90%) and stable electrosynthesis over 80 h of continuous operation, highlighting their robustness. Density functional theory calculations reveal that the facets of the pillars enhance catalytic activity by reducing the OOH adsorption strength, thereby lowering the overpotential. This study underscores the importance of facet engineering in optimizing catalytic performance and provides a pathway for designing advanced TMP-based materials for energy and environmental applications. 2025-05-27T15:00:00Z