https://scholar.dgist.ac.kr/handle/20.500.11750/56976 2026-08-03T10:44:59Z 2026-08-03T10:44:59Z Lee, Jieun Kim, Junil Sim, Young-Jun Lee, Byeongmoon Jang, Jae Eun Kwon, Hyuk-Jun https://scholar.dgist.ac.kr/handle/20.500.11750/60480 2026-07-23T03:10:14Z 2026-04-30T15:00:00Z

Title: Laser-Induced Oxygen Engineering for Localized Homojunction Formation in SnS2 Photodetectors Author(s): Lee, Jieun; Kim, Junil; Sim, Young-Jun; Lee, Byeongmoon; Jang, Jae Eun; Kwon, Hyuk-Jun Abstract: The development of high-performance optoelectronic devices based on 2D materials has attracted significant attention. However, conventional vertical stacking methods are limited by complex processes and interfacial defects. To overcome these challenges, we propose a simple and efficient one-step process to form an in-plane homojunction within a single n-type tin disulfide (SnS2) flake via direct laser irradiation. The core process, oxidative thinning, utilizes a focused 532 nm laser to locally convert a portion of SnS2 into tin oxide (SnOx). Consequently, an energy barrier arising from a work-function difference of approximately 0.7 eV is formed at the interface, promoting the separation of photogenerated electron-hole pairs. The fabricated photodetector demonstrates a fast response time (tau r/tau f = 474/299 ms), an improvement of several tens of times compared with the pristine SnS2 device. Furthermore, it exhibits a high responsivity (R) of 703 mA W-1, an external quantum efficiency (EQE) of 170%, and a remarkable specific detectivity (D*) of 2.35 x 1014 Jones, along with excellent operational stability. This laser-induced local conversion technique presented can provide a powerful and practical platform for developing next-generation flexible and wearable optoelectronic devices.

2026-04-30T15:00:00Z Sim, Young-Jun Kim, Junil Lee, Jieun Lee, Byeongmoon Jang, Jae Eun Kwon, Hyuk-Jun https://scholar.dgist.ac.kr/handle/20.500.11750/59972 2026-02-09T18:01:14Z 2025-11-30T15:00:00Z

Title: Hole Current Enhancement Using W1-x Cr x Se2 Alloy Interface for p-Type WSe2 FETs Author(s): Sim, Young-Jun; Kim, Junil; Lee, Jieun; Lee, Byeongmoon; Jang, Jae Eun; Kwon, Hyuk-Jun Abstract: Two-dimensional (2D) transition-metal dichalcogenides (TMDs) have emerged as promising candidates for next-generation semiconductor devices. Among TMDs, tungsten diselenide (WSe2) is regarded as an ideal material for p-type field-effect transistors (FETs). However, the realization of high-performance p-type devices remains limited due to undesired ambipolar behavior and high contact resistance. These challenges originate from Fermi level pinning (FLP) caused during conventional deposition processes. Although van der Waals (vdW) contacts have been introduced to overcome FLP, their implementation faces difficulties due to contamination-induced degradation and limitations in CMOS process compatibility. In this study, we demonstrate a scalable approach for p-type contact via the W1-xCrxSe2 alloy interface. It has been reported that Cr incorporation reduces the bandgap of WSe2, while CrxSey exhibits p-type semimetal properties. Leveraging these properties, thermal annealing of Cr contacts enables the formation of WSe2/W1-xCrxSe2/Cr layers at the contact region. This interfacial alloy effectively suppresses FLP, eliminates undesirable ambipolar behavior, and enhances hole injection. The resulting devices achieve a Schottky barrier height as low as 61.1 meV and reduce contact resistance by approximately 3 orders of magnitude. Consequently, W1-xCrxSe2 alloy interface contact WSe2 FETs exhibit robust p-type performance with an average on/off current ratio of 2.19 x 10(8) across 20 devices. These findings present a practical and scalable strategy for engineering low-resistance p-type contacts in WSe2, providing an important step toward the integration of TMD-based complementary logic in future scaled CMOS technologies.

2025-11-30T15:00:00Z Kim, Hwajoong Kim, Daehyeon Kim, Jinho Lee, Yukye Shin, Minchang Kim, Jimin Bossuyt, Fransiska M. Lee, Gun-Hee Lee, Byeongmoon Taylor, William R. Lee, Jaehong https://scholar.dgist.ac.kr/handle/20.500.11750/59033 2026-01-14T18:01:08Z 2025-07-31T15:00:00Z

Title: Advances and perspectives in fiber-based electronic devices for next-generation soft systems Author(s): Kim, Hwajoong; Kim, Daehyeon; Kim, Jinho; Lee, Yukye; Shin, Minchang; Kim, Jimin; Bossuyt, Fransiska M.; Lee, Gun-Hee; Lee, Byeongmoon; Taylor, William R.; Lee, Jaehong Abstract: Fiber-based electronic devices (FEDs) exhibit high flexibility, low weight, and excellent integrability into wearable, implantable, and robotic systems. Recent advances have enabled applications in sensing, energy harvesting, and storage, and active functions. Despite this progress, challenges such as mechanical fatigue, interfacial delamination, and signal instability remain. This review offers key challenges and perspectives on the future of FEDs as interactive, autonomous platforms for next-generation electronics in healthcare, robotics, and beyond.

2025-07-31T15:00:00Z Lee, Seunghwan Yoon, Jinsu Lee, Byeongmoon Hong, Yongtaek https://scholar.dgist.ac.kr/handle/20.500.11750/58969 2025-08-29T02:40:12Z 2025-06-30T15:00:00Z

Title: Stretchable bioinspired compound eye structures with curved microlens arrays via a dry-phase rubbing process Author(s): Lee, Seunghwan; Yoon, Jinsu; Lee, Byeongmoon; Hong, Yongtaek Abstract: A stretchable bioinspired compound (BIC) eye structure with a combination of dispensing and dry-phase rubbing processes is proposed as a printed optical component. A hemispherical macrolens is formed by the dispensing method, followed by a dry-phase rubbing process for arranging microparticles in monolayers onto the curved surface of the macrolens. This hierarchical structure is replicated in soft materials, which have intrinsic stretchability. A microlens array is formed on the surface of the macrolens and acts as a rigid island, thereby maintaining lens shape and resolution even though mechanical strain is applied to the overall hierarchical structures and the shape of the macrolens is changed. (c) 2025 Optica Publishing Group. All rights, including for text and data mining (TDM), Artificial Intelligence (AI) training, and similar technologies, are reserved.

2025-06-30T15:00:00Z