https://scholar.dgist.ac.kr/handle/20.500.11750/10028 2026-04-04T15:17:59Z 2026-04-04T15:17:59Z 최종민 https://scholar.dgist.ac.kr/handle/20.500.11750/57759 2025-07-25T02:42:46Z 2024-04-03T15:00:00Z

Title: Material Engineering Strategies for Boosting Performance and Stability of Quantum Dot and Perovskite Photovoltaics Author(s): 최종민 Abstract: Metal-halide perovskites and PbS quantum dots (CQDs) are recognized for their superb optoelectronic properties, positioning them as crucial materials for the next generation of solar cells. Advances in this field have pushed power conversion efficiencies (PCE) to 12.43% for PbS CQDs and 26.1% for perovskites. Despite this progress, there remain significant challenges, including the need for efficient charge transport and the development of sophisticated material and device architectures. A particular problem in CQD solar cells is the accumulation of holes due to mismatches in Fermi levels, which restricts further improvements in performance. Additionally, the natural vulnerability of perovskites to oxygen and moisture, particularly at grain boundaries created during film production, undermines the stability of devices. This presentation will delve into these issues facing perovskite and CQD solar cell advancements and will outline possible solutions for enhancing their performance.

2024-04-03T15:00:00Z 유형렬 최종민 https://scholar.dgist.ac.kr/handle/20.500.11750/57757 2025-07-25T02:42:46Z 2024-04-02T15:00:00Z

Title: Organic Solvent Dispersible MXene for Band Alignment and Interface Engineering of Colloidal Quantum Dot Photovoltaics Author(s): 유형렬; 최종민 Abstract: Despite the recent developments in colloidal quantum dot (CQD) photovoltaics the unfavorable energy band for hole collection and the surface cracks lowers the device performance. To address these issues, we developed polycatechol functionalized MXene (PCA-MXene), which act as an interlayer and a dopant and an interlayer in CQD photovoltaics. PCA-MXene achieves a consistently dispersed mixture in a butylamine solvent, which makes MXene and CQDs work together effectively. As a result, the energy band alignment is modulated and the work function of CQDs is altered, which eventually leads to improved hole extraction. Furthermore, the surface cracks in the thiol-treated CQD layer eliminated by the PCA-MXene interlayer. Owing to these benefits, the PCA-MXene-integrated CQD device shows a 13.6% power conversion efficiency (PCE) compared to the reference device, which has a PCE of 12.8%.

2024-04-02T15:00:00Z 한상훈 최종민 김영훈 https://scholar.dgist.ac.kr/handle/20.500.11750/57755 2025-07-25T02:42:59Z 2024-04-04T15:00:00Z

Title: Facile Surface Stabilization Strategy for Efficient and Stable Perovskite Quantum Dot Solar Cells Author(s): 한상훈; 최종민; 김영훈 Abstract: CsPbI3 PQD solids suffer from degradation in optoelectrical properties and film stability because of numerous trap sites on the PQD surface, which are generated after the ligand exchange process. Therefore, additional PQD surface stabilization strategy should be introduced which can improve the film quality of CsPbI3 PQD solids using covalent short-chain triphenylphosphine oxide (TPPO) ligands dissolved in an octane solvent. It is found that the TPPO ligand can bind with trap sites through Lewis-base interaction and the nonpolar solvent octane can preserve the PQD surface. As a result, the CsPbI3 PQD solids stabilized using the TPPO-octane solution showed reduced surface trap density than the control PQD solids. Consequently, CsPbI3 PQD solar cells which were stabilized using TPPO-octane solution provide a boosted power conversion efficiency and operational stability compared to control device.

2024-04-04T15:00:00Z 함가영 유형렬 최종민 차효정 https://scholar.dgist.ac.kr/handle/20.500.11750/57741 2025-07-25T03:27:59Z 2023-10-11T15:00:00Z

Title: Investigating the Influence and Charge Carrier Dynamics of PCA-MXene-Integrated Colloidal Quantum Dot Photovoltaics through Transient Absorption Analysis Author(s): 함가영; 유형렬; 최종민; 차효정 Abstract: Lead sulfide colloidal quantum dot (PbS-CQD) have attracted significant interest due to their tunable bandgap, multi-exciton generation effect and ambient solution processing, which makes them photovoltaic materials for low-cost, large-area and flexible solar cells. Despite there are several challenges, the Fermi level mismatch between the PbS-CQD layer and hole transport layer results in the formation of energy bands that are not conducive to efficient hole collection, and the presence of numerous surface cracks in the thiol-treated CQD layer diminished device performance. To address these issues, we develop a polycatechol functionalized MXene (PCA-MXene) as an interlayer to enhance hole extraction. The effectiveness of PCA-MXene was validated through measurements utilizing time-resolved photoluminescence (TRPL) and transient absorption (TA) spectroscopy. By analyzing the charge carrier dynamics, we obtain hole transfer in the positive impact of PCA-MXene-based CQD solar cells.

2023-10-11T15:00:00Z