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293 results on '"Yoon, Jinhwan"'

9. Accomplishing High‐Performance Organic Solar Sub‐Modules (≈55 cm2) with >16% Efficiency by Controlling the Aggregation of an Engineered Non‐Fullerene Acceptor.

Author

Gokulnath, Thavamani, Kim, Hyerin, Kranthiraja, Kakaraparthi, Cho, Bo Hyeon, Park, Ho‐Yeol, Jee, Jesung, Kim, Young Yong, Yoon, Jinhwan, and Jin, Sung‐Ho

Subjects
SOLUBILITY, SOLVENTS, ELECTROPHILES, HUMIDITY, ENGINEERING, MORPHOLOGY, MISCIBILITY
Abstract

The fabrication of environmentally benign, solvent‐processed, efficient, organic photovoltaic sub‐modules remains challenging due to the rapid aggregation of the current high performance non‐fullerene acceptors (NFAs). In this regard, design of new NFAs capable of achieving optimal aggregation in large‐area organic photovoltaic modules has not been realized. Here, an NFA named BTA‐HD‐Rh is synthesized with longer (hexyl‐decyl) side chains that exhibit good solubility and optimal aggregation. Interestingly, integrating a minute amount of new NFA (BTA‐HD‐Rh) into the PM6:L8‐BO system enables the improved solubility in halogen‐free solvents (o‐xylene:carbon disulfide (O‐XY:CS2)) with controlled aggregation is found. Then solar sub‐modules are fabricated at ambient condition (temperature at 25 ± 3 °C and humidity: 30–45%). Ultimately, the champion 55 cm2 sub‐modules achieve exciting efficiency of >16% in O‐XY:CS2 solvents, which is the highest PCE reported for sub‐modules. Notably, the highest efficiency of BTA‐HD‐Rh doped PM6:L8‐BO is very well correlated with high miscibility with low Flory‐Huggins parameter (0.372), well‐defined nanoscale morphology, and high charge transport. This study demonstrates that a careful choice of side chain engineering for an NFA offers fascinating features that control the overall aggregation of active layer, which results in superior sub‐module performance with environmental‐friendly solvents. [ABSTRACT FROM AUTHOR]

Published
2024
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14. High Performance Air‐Processed Organic Photovoltaic Modules (≈55 cm2) with an Efficiency of >17.50% by Employing Halogen‐Free Solvent Processed Polymer Donors

Author

Gokulnath, Thavamani, primary, Kim, Hyerin, additional, Lee, Jieun, additional, Cho, Bo Hyeon, additional, Park, Ho‐Yeol, additional, Jee, Jesung, additional, Kim, Young Yong, additional, Kranthiraja, Kakaraparthi, additional, Yoon, Jinhwan, additional, and Jin, Sung‐Ho, additional

Published
2023
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16. High Performance Air‐Processed Organic Photovoltaic Modules (≈55 cm2) with an Efficiency of >17.50% by Employing Halogen‐Free Solvent Processed Polymer Donors.

Author

Gokulnath, Thavamani, Kim, Hyerin, Lee, Jieun, Cho, Bo Hyeon, Park, Ho‐Yeol, Jee, Jesung, Kim, Young Yong, Kranthiraja, Kakaraparthi, Yoon, Jinhwan, and Jin, Sung‐Ho

Subjects
PHOTOVOLTAIC power systems, CONJUGATED polymers, CHARGE carrier mobility, SOLVENTS, SOLAR cells, POLYMERS
Abstract

Organic photovoltaic (OPV) sub‐modules shall be feasible for production using halogen‐free solvents in air,high power conversion efficiencies (PCEs), and long‐term stability, which are challenging requirements. To achieve this goal, air‐processed OPVs are fabricated by employing a synthesized set of π‐conjugated polymers, NAP‐T‐SiBTZ (P1) and NAP‐TT‐SiBTZ (P2), with thiophene and thienothiophene π‐spacers, respectively. P1 and P2 incorporated ternary OPVs show excellent PCEs and are used to produce small‐area, sub‐module air‐processed devices using o‐xylene as the solvent. Interestingly, P2‐added ternary devices has remarkable PCEs of 17.62% (PM6:P2:Y7) and 17.96% (PM6:P2:L8‐BO), which is the highest reported for air‐processed OPVs.. Notably, P2‐associated ternary blends exhibit a nano‐morphology, increased charge carrier mobilities, exciton dissociation, and decreased non‐geminate recombination, which are deemed responsible for the enhanced PCEs observed. In addition, P2 demonstrates high efficiency for a thick‐film device (>300 nm), with a PCE of >16.50%. Notably, a 55 cm2 sub‐module produced by bar coating using o‐xylene in open air has a PCE of 13.88%. Additionally, P2‐containing devices demonstrate impressive thermal and photo‐stabilities. This study shows the potential of an OPV that may be used to produce low‐cost solar cell sub‐module at low cost with exceptional commercial value. [ABSTRACT FROM AUTHOR]

Published
2023
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19. Finely Tuned Molecular Packing Realized by a New Rhodanine-Based Acceptor Enabling Excellent Additive-Free Small- and Large-Area Organic Photovoltaic Devices Approaching 19 and 12.20% Efficiencies

Author

Gokulnath, Thavamani, primary, Kim, Jeonghyeon, additional, Kim, Hyerin, additional, Park, Jeonghyeon, additional, Song, Donghyun, additional, Park, Ho-Yeol, additional, Kumaresan, Raja, additional, Kim, Young Yong, additional, Yoon, Jinhwan, additional, and Jin, Sung-Ho, additional

Published
2023
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20. Smart Skin‐Adhesive Patches: From Design to Biomedical Applications

Author

Wong, Siu Hong Dexter, primary, Deen, G. Roshan, additional, Bates, Jeffrey S., additional, Maiti, Chiranjit, additional, Lam, Ching Ying Katherine, additional, Pachauri, Abhishek, additional, AlAnsari, Renad, additional, Bělský, Petr, additional, Yoon, Jinhwan, additional, and Dodda, Jagan Mohan, additional

Published
2023
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28. Thienothiophene‐Assisted Property Optimization for Dopant‐Free π‐Conjugation Polymeric Hole Transport Material Achieving Over 23% Efficiency in Perovskite Solar Cells.

Author

Xie, Zhiqing, Park, Hyungjin, Choi, SeungJu, Park, Ho‐Yeol, Gokulnath, Thavamani, Kim, Hyerin, Kim, Jeonghyun, Kim, Hak‐Beom, Choi, In Woo, Jo, Yimhyun, Kim, Dong Suk, Kim, Young‐Yong, Yoon, Seog Young, Yoon, Jinhwan, Cho, Yong‐Rae, and Jin, Sung‐Ho

Subjects
SOLAR cell efficiency, CHARGE carrier mobility, PHOTOVOLTAIC power systems, PEROVSKITE, BAND gaps, SOLAR cells, SMALL molecules
Abstract

Hole transport materials (HTMs) play essential roles in achieving high photovoltaic performance and long‐term stability in the n–i–p structure of perovskite solar cell (PSC) devices. Recently, dopant‐free polymeric materials as HTMs in PSCs have attracted considerable attention owing to high carrier mobility and excellent hydrophobicity. However, achieving similar efficiencies to those of doped small molecule HTMs such as Spiro‐OMeTAD is a big challenge. Herein, a thienothiophene π‐bridge is selected as a stabilizer and energy level regulator incorporated into a donor–acceptor‐type HTM to synthesize a new polymer, Nap‐SiBTA. The incorporation of the thienothiophene group improves the thermal stability and favors the high planarity and face‐on orientation, promoting high charge carrier mobility and tunable optical band gap. Finally, the dopant‐free polymer Nap‐SiBTA‐based PSC achieves an excellent power conversion efficiency (PCE) of 23.07% with a high fill factor of 80.85%. To the best of the authors' knowledge, this is one of the best efficiencies in dopant‐free HTM PSCs. Moreover, the unencapsulated device retains 93% of its initial PCE after 1000 h owing to the excellent hydrophobicity of Nap‐SiBTA. This work provides a general and practical method to design dopant‐free HTMs for the high efficiency and long‐term stability of PSCs. [ABSTRACT FROM AUTHOR]

Published
2023
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34. All-Polymer Solar Cells Approaching 12% Efficiency with a New π-Conjugated Polymer Donor Enabled by a Nonhalogenated Solvent Process

Author

Gokulnath, Thavamani, primary, Choi, Jungmin, additional, Jin, Hyunjung, additional, Park, Ho-Yeol, additional, Sung, Kyungmin, additional, Do, Yeongju, additional, Park, Hyungjin, additional, Reddy, Saripally Sudhaker, additional, Kim, Jehan, additional, Song, Myungkwan, additional, Yoon, Jinhwan, additional, and Jin, Sung-Ho, additional

Published
2021
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44. Synthesis and non-isothermal crystallization behavior of poly(ethylene phthalate-co-terephthalate)s

Author

Lee, Byeongdu, Lee, Jin Won, Lee, Seung Woo, Yoon, Jinhwan, and Ree, Moonhor

Subjects
Polyethylene terephthalate -- Research, Engineering and manufacturing industries, Science and technology
Abstract

A series of poly(ethylene phthalate-co-terephthalate)s were synthesized by melt polycondensation of ethylene glycol (EG) with dimethyl phthalate (DMP) and dimethyl terephthalate (DMT) in various proportions. The DMT-rich polymers were obtained with reasonably high molecular weights, whereas the DMP-rich polymers were synthesized with relatively low molecular weights due to steric effects associated with the highly kinked DMP monomer. The compositions and thermal properties of the polymers were determined. The copolymers containing DMP in amounts of [less than or equal to] 21 mol% were crystallizable, whereas the other polymers were not. All the polymers exhibited a single glass transition temperature. Analysis of the measured glass transition temperatures and crystal melting temperatures confirmed that the DMT-rich copolymers are random copolymers. The non-isothermal crystallization behaviors of the DMT-rich copolymers were investigated by calorimetry and modified Avrami analysis. The Avrami exponents n were found to range from 2.7 to 3.8, suggesting that the copolymers crystallize via a heterogeneous nucleation and spherulitic growth mechanism; that is, the incorporation of DMP units as the minor component does not change the growth mechanism of the copolymers. In addition, the activation energies of the crystallizations of the copolymers were determined; the copolymers were found to have higher activation energies than the PET homopolymer. Polym. Eng. Sci. 44:1682-1691, 2004. [c] 2004 Society of Plastics Engineers., INTRODUCTION Poly(ethylene terephthalate) (PET) has excellent thermal and mechanical properties, high chemical resistance, and low gas permeability (1-3). Because of these advantageous properties, this polyester is widely used in synthetic [...]

Published
2004

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