https://scholarworks.unist.ac.kr/handle/201301/85 2026-05-13T05:30:49Z https://scholarworks.unist.ac.kr/handle/201301/91626 Title: Suppressing Molecular Aggregation Enables Efficient and Thermally Stable Ternary Bilayer Organic Solar Cells Author(s): Lee, Woojin; Cho, Hye Won; Lee, Tack Ho; Lee, Dongchan; Yoon, Yung Jin; Park, Sujung; Cho, Shinuk; Kim, Jin Young; Park, Song Yi Abstract: Bilayer organic solar cells (OSCs) have been actively investigated due to more ideal photoactive layer structures and possibly better device stability compared to those of bulk-heterojunction OSCs. Here, we introduce a binary non-fullerene acceptor layer composed of IDIC and IT-4F into bilayer OSCs and investigate its effects on device performance and thermal stability. We found that IT-4F suppresses IDIC aggregation, which provides ideal interface morphologies between acceptor and electron transport layers, resulting in improved power conversion efficiency. In addition, due to suppressed IDIC aggregation, PM6/IDIC:IT-4F films showed robust thermal durability upon various pre-annealing test conditions. Moreover, PM6/IDIC:IT-4F bilayer OSCs exhibited improved stability compared to that of PM6/IDIC devices under continuous thermal annealing conditions. Whereas all photovoltaic parameters deteriorated upon thermal annealing in PM6/IDIC devices, only open-circuit voltages were reduced in PM6/IDIC:IT-4F devices, possibly due to a minor aggregation of IDIC. Nevertheless, binary acceptor layer reduced non-radiative voltage losses in bilayer OSCs, suggesting that there is more room to achieve better device stability by proper material selection. This work demonstrates that introducing a binary acceptor layer into bilayer OSCs can be an effective strategy to achieve both high efficiency and improved stability, especially when the given NFA tends to aggregate strongly. 2026-02-28T15:00:00Z https://scholarworks.unist.ac.kr/handle/201301/91578 Title: Catalytic cracking of ammonia and combustion of cracked ammonia: An integrated system for industrial applications - Mini review Author(s): Lee, Woo Jin; Tang, Liangguang; Patel, Jim; Orellana, Jose; Choi, Daniel; Choi, Jae Hyung; Kim, Tae-Wan; Chae, Ho-Jeong; Lim, Hankwon; Dumaop, Jhon Nepo Zeus; Sun, Biao Abstract: Ammonia is increasingly recognised as a key enabler for achieving global low-emission targets, serving both as a hydrogen carrier and an energy vector suitable for long-distance transport. In the near term, it is expected to play an important transitional role until renewable hydrogen becomes cost-competitive. Within the ammonia energy value chain, catalytic decomposition (cracking) forms the core of the ammonia-to-hydrogen pathway, while direct combustion provides the ammonia-to-power pathway. Catalytic cracking typically operates at 500-800 degrees C and can generate hydrogen-rich mixtures with controllable cracking rates (CRs) of 20-80%, enabling partial decomposition to tailor fuel reactivity. Such hydrogen enrichment has been shown to increase laminar burning velocities by more than twofold compared with pure ammonia and to broaden flammability limits, while thermally integrated configurations can recover approximately 60-85% of combustion heat to supply the endothermic cracking demand. This review summarizes recent progress, challenges, and prospects of catalytic ammonia cracking and the combustion of cracked ammonia fuel blends, followed by system-level discussions of heat integration and performance trade-offs. Advances in cost-effective catalysts and reactor designs are examined alongside combustion characteristics, nitrogen oxide (NOx/N2O) formation mechanisms, and mitigation strategies. Finally, emerging integrated systems and commercial developments are highlighted, and key technical barriers-including heat matching, emissions control, and durability - are identified to guide future deployment of ammonia-based clean energy technologies. 2026-03-31T15:00:00Z https://scholarworks.unist.ac.kr/handle/201301/91573 Title: Integrated overview of solvents and materials for reactive carbon capture and utilization Author(s): Choe, Changgwon; Kim, Mingi; Quintana, Cristóbal; Lim, Hankwon Abstract: Carbon dioxide (CO2) capture remains a critical strategy for environmental decarbonization and achieving net-zero emissions in power generation and industrial sectors. Over the last two decades, diverse solvent-based strategies have emerged, involving absorbents such as aqueous amines, deep eutectic solvents (DESs), enzymes, ionic liquids (ILs), porous materials, and electrochemically regenerable solutions. While each class offers distinct advantages in reactivity, stability, and regeneration energy, direct comparisons across solvent types remain limited, hindering rational material selection for specific capture scenarios. Furthermore, emerging applications such as direct air and ocean capture, integrated capture and utilization (ICCU), as well as techno-economic analysis (TEA), introduce new challenges for solvent performance, compatibility, and process integration. This review provides a comprehensive assessment of solvent-based CO2 capture technologies, with an emphasis on performance metrics such as absorption capacity, regeneration energy, cycling efficiency, and economic viability. By integrating insights from molecular design, process engineering, and TEA, this review aims to provide a practical guide for the development and deployment of next-generation CO2 capture sorbents. 2026-03-31T15:00:00Z https://scholarworks.unist.ac.kr/handle/201301/91503 Title: Hydrogen Purification through a Membrane–Cryogenic Integrated Process: A 3 E’s (Energy, Exergy, and Economic) Assessment Author(s): Naquash, Ahmad; Riaz, Amjad; Yehia, Fatma; Chaniago, Yus Donald; Lim, Hankwon; Lee, Moonyong Abstract: Hydrogen (H2) is known for its clean energy characteristics. Its separation and purification to produce high-purity H2 is becoming essential to promoting a H2 economy. There are several technologies, such as pressure swing adsorption, membrane, and cryogenic, which can be adopted to produce high-purity H2; however, each standalone technology has its own pros and cons. Unlike standalone technology, the integration of technologies has shown significant potential for achieving high purity with a high recovery. In this study, a membrane–cryogenic process was integrated to separate H2 via the desublimation of carbon dioxide. The proposed process was designed, simulated, and optimized in Aspen Hysys. The results showed that the H2 was separated with a 99.99% purity. The energy analysis revealed a net-specific energy consumption of 2.37 kWh/kg. The exergy analysis showed that the membranes and multi-stream heat exchangers were major contributors to the exergy destruction. Furthermore, the calculated total capital investment of the proposed process was 816.2 m$. This proposed process could be beneficial for the development of a H2 economy. © 2023 by the authors. 2023-05-31T15:00:00Z