https://scholarworks.unist.ac.kr/handle/201301/50 2026-04-08T21:25:01Z https://scholarworks.unist.ac.kr/handle/201301/91316 Title: Highly Transparent, Self-Healable Stretchable Conductors for Skin-Attachable Transparent Bioelectronic Sensors and Synesthesia Displays Author(s): Kim, Yaewon; Song, Sunwu; Kim, Hye Hyun; Choi, Jinho; Yoo, Jisu; Yun, Eunhye; Yu, Changhoon; Son, Hui Yong; Cha, Chaenyung; Kwon, Min Sang; Choi, Moon Kee Abstract: Transparent and stretchable conductors are essential components for next-generation soft electronics. However, simultaneously achieving high electrical conductivity, optical transparency, stretchability, and self-healing capability within a single conductor is challenging, because optical clarity and electrical performance are often traded off. Here, we introduce a multifunctional transparent stretchable conductor consisting of a micropatterned liquid metal (LM) mesh embedded within a self-healing elastomeric matrix. This innovative architecture delivers high optical transparency (81.6%), exceptional stretchability (>1,000%), low sheet resistance (2.5 Omega sq(-1)), and robust self-healing functionality (86.4% toughness restoration at 60 degrees C for 2 h). The patterned LM network maintains continuous electrical conductivity under extreme and repeated mechanical deformation, while the elastomer matrix rapidly restores its structural integrity with only thermal stimuli. To demonstrate practical applicability, this transparent stretchable conductor is implemented in wearable sensors, enabling stable electrocardiogram (ECG) and electromyogram (EMG) signal acquisition under repeated deformation. Additionally, integration as a transparent electrode in a stretchable, alternating current-driven display yielded a peak luminance of 2,500 cd m(-2) with synchronized acoustic emission (similar to 73 dB). These findings highlight the significant potential of the conductor for robust and multifunctional wearable and optoelectronic devices capable of operating reliably in dynamic, deformable environments. 2025-12-31T15:00:00Z https://scholarworks.unist.ac.kr/handle/201301/91315 Title: Controlling the Hole Injection Dynamics of Hole-Transporting Polymers for Efficient Quantum Dot Light-Emitting Diodes Author(s): Seomun, San; Choi, Sun-Gi; Ryu, Ji Yeon; Kim, In; Kim, Hyuna; Cho, Han-Hee; Choi, Youngmin; Jung, Sungmook; Kim, Tae Yeon; Oh, Nuri; Lee, Su Yeon; Kim, Taesu Abstract: State-of-the-art quantum dot light-emitting diodes (QD-LEDs) have largely relied on poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4 '-(N-(4-sec-butylphenyl))diphenylamine)] (TFB) as the hole transport layer (HTL). However, the relatively high highest occupied molecular orbital (HOMO) energy level of the TFB hinders hole transfer into emitting layers (EMLs). In this study, we introduce fluorine (F) as a weak electron-withdrawing group (EWG) and the cyano group (CN) as a strong EWG into triphenylamine units of TFB to reduce the energy offset between HTLs and EMLs. Fluorination selectively downshifts HOMO energy levels and slightly improves the hole mobility of the TFB derivatives, leading to a significant enhancement of the external quantum efficiencies (EQEs) in red-emissive CdSe and blue-emissive ZnSe QD-LEDs. Specifically, using difluorinated TFB (2F-TFB) as HTLs in the red and blue QD-LED devices improves EQE to 17.4% and 10.6%, compared to the conventional TFB-based devices with EQEs of 13.3% and 5.0%, respectively. However, the devices with the TFB derivative incorporating CN (CN-TFB) show poor EQEs of 8.1% and 0.5% for the red and blue devices, respectively, due to the reduced hole mobility of CN-TFB and, in the blue devices, to enhanced electron leakage from the EMLs into the HTLs. The results show that beyond deepening the HTL HOMO to lower the hole injection barrier at the HTL/EML interface, effective HTL design must also balance hole mobility and electron blocking in order to maintain charge balance in QD-LEDs. 2025-12-31T15:00:00Z https://scholarworks.unist.ac.kr/handle/201301/91305 Title: Toward self-driving laboratory 2.0 for chemistry and materials discovery Author(s): Lee, Heeseung; Yoo, Hyuk Jun; Jang, Hye Su; Park, Byeongho; Park, Yang Jeong; Han, Sang Soo Abstract: The convergence of laboratory automation, artificial intelligence (AI), and data-driven science has catalyzed the emergence of self-driving laboratories (SDLs), autonomous platforms capable of designing, executing, and analyzing experiments with minimal human input. While early SDLs (SDL 1.0) demonstrated the feasibility of closed-loop discovery, their impact has been constrained by limited scope, poor interoperability, and reliance on human-curated heuristics. This review outlines the vision of SDL 2.0: a new generation of flexible, scalable, and collaborative discovery engines for chemistry and materials science. We discuss recent advances in modular hardware design, AI-driven decision-making including Bayesian optimization, computer vision, and large language models, and orchestration software that integrate scheduling, data management, and safety protocols. Building on these foundations, we propose six defining characteristics for SDL 2.0: interoperable, collaborative, generalizable, orchestrated, safe, and creative. Together, these features establish SDLs as globally networked platforms, enabling reproducible experimentation, accelerated innovation, and democratized access to advanced research infrastructure. By embedding modularity, AI reasoning, and community-driven standards into their core, SDLs 2.0 promise to transform not only how experiments are conducted, but also who can participate in and benefit from the accelerating pace of scientific discovery. 2026-02-28T15:00:00Z https://scholarworks.unist.ac.kr/handle/201301/91301 Title: Enhanced functional properties of ABC-type atomic layer deposited Ru thin films for advanced Cu alternative nanoscale interconnects Author(s): Kim, Jeongha; Mohapatra, Debananda; Son, Yeseul; Jang, Jae Min; Kim, Sang Bok; Hong, Tae Eun; Cheon, Taehoon; Shong, Bonggeun; Kim, Soo-Hyun Abstract: Atomic layer deposition (ALD) technology requires high-temperature processes to achieve low resistivity, large grain size, and fewer impurities in ultrathin interconnects; however, the thermal stability of the precursor often constrains this approach. This study presents a novel ABC-type ALD process, using [tricarbonyl(trimethylenemethane)ruthenium, [Ru(TMM)(CO)3]] as the Ru precursor and two counter-reactants (O2 and NH3) sequentially, to deposit highly conductive ruthenium (Ru) thin films at a high temperature of 310 degrees C. A key innovation of this work is that grain growth occurs without the need for annealing. Compared to the conventional AB-type Ru ALD process, the ABC-type process significantly reduces resistivity from 20.1 & micro;Omega cm to 13.4 & micro;Omega cm. In addition to resistivity reduction, the process also improves surface roughness and reduces impurities in the Ru film. Using the Fuchs-Sondheimer and Mayadas-Shatzkes' model, the study quantitatively identifies the contribution of various factors to achieving low resistivity, highlighting grain size as the critical factor for this achievement. Moreover, machine learning potential (MLP) analysis was used to explore the adsorption and decomposition mechanisms of NH3, providing valuable theoretical insights that support the chemical rationale behind the surface reactions. Finally, the Ru thin films deposited by the ABC-type Ru ALD process achieve excellent step coverage on high-aspect-ratio trench patterns (similar to 30, opening width: 140 nm), presenting a breakthrough approach for next-generation nanoscale interconnects. 2026-02-28T15:00:00Z