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6. Design of plasma strip chamber for uniform gas supply with fluid flow simulation.

Author

Jang, Ji Won, Jo, Se Yun, and Hong, Sang Jeen

Subjects
COMPUTATIONAL fluid dynamics, SEMICONDUCTOR manufacturing, GAS distribution, FLOW simulations, RADICALS (Chemistry)
Abstract

Within the domain of semiconductor fabrication, which entails progressively complex patterning steps, the significance of plasma stripping processes, particularly to achieve the effective stripping of photoresist (PR) without damaging the underlying substrates via uniform gas distribution across 300 mm wafers, cannot be overstated. The efficacy of plasma stripping is influenced by the design of the components of the process chamber, which is critical for advancing semiconductor manufacturing technologies. In this study, we elucidated the influence of the design of a process chamber, particularly the showerhead nozzle angles, on the plasma chemical reactions of radicals emanating from conventional PR equipment using computational fluid dynamics simulations. We assessed the impact of the showerhead design, which incorporated divergent or angled gas supply nozzles, on the distribution of the supply gas across the wafer within the process chamber. Five distinct angles of showerhead nozzles were investigated, and the uniformity of the oxygen mass fractions was optimized for nozzle angles of 45° and 60°. Additionally, the factors contributing to the low uniformity in a showerhead design were identified and design components were modified, resulting in a 16% improvement in uniformity. This study delineated the relationship between the nozzle position, mass fraction, and flow streamlines, thereby establishing the critical role of equipment design for enhancing the plasma stripping process. Furthermore, this principle transcends the realm of stripping equipment design; it is anticipated that incorporating flow dynamics simulations for designing process components will enhance the overall process performance. [ABSTRACT FROM AUTHOR]

Published
2024
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11. Thermal Management Enables Stable Perovskite Nanocrystal Light‐Emitting Diodes with Novel Hole Transport Material (Small 45/2023)

Author

Shen, Xinyu, primary, Kwak, Seon Lee, additional, Jeong, Woo Hyeon, additional, Jang, Ji Won, additional, Yu, Zhongkai, additional, Ahn, Hyungju, additional, Park, Hea Jung, additional, Choi, Hyosung, additional, Park, Sung Heum, additional, Snaith, Henry J., additional, Hwang, Do‐Hoon, additional, and Lee, Bo Ram, additional

Published
2023
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13. Phosphine oxide modulator-ameliorated hole injection for blue perovskite light-emitting diodes

Author

Fan, Xiangyang, Wang, Yu, Shen, Xinyu, Yu, Zhongkai, Jeong, Woo Hyeon, Jang, Ji Won, Kim, Yeong Gyeong, Woo, Seung-Je, Ahn, Hyungju, Choi, Hyosung, Lee, Tae-Woo, Park, Sung Heum, Gao, Feng, Lee, Bo Ram, Fan, Xiangyang, Wang, Yu, Shen, Xinyu, Yu, Zhongkai, Jeong, Woo Hyeon, Jang, Ji Won, Kim, Yeong Gyeong, Woo, Seung-Je, Ahn, Hyungju, Choi, Hyosung, Lee, Tae-Woo, Park, Sung Heum, Gao, Feng, and Lee, Bo Ram

Abstract

Despite the enormous developments in perovskite light-emitting diodes (PeLEDs) recently, obtaining efficient blue PeLEDs is still considered a critical challenge due to the non-radiative recombination and unbalanced charge injection caused by the unmatched carrier mobility and the deep hole-injection barrier between the hole-transport layer (HTL) and the emissive layer (EML). Herein, we incorporate tris(4-trifluoromethylphenyl)phosphine oxide (TMFPPO), obtained through a facile oxidation synthesis process, into poly(9-vinylcarbazole) (PVK). TMFPPO incorporation modulated the energy level and hole mobility of the binary-blend HTLs to eliminate the hole-injection barrier and balance the charge injection within the EML. Consequently, the blue PeLEDs with blended HTL presented an external quantum efficiency (EQE) of 7.23% centred at 477 nm, which was much higher than the EQE of a PVK device (4.95%). Our results demonstrate that modulating the energy level and charge injection of the HTL in the device is a promising method for obtaining efficient blue PeLEDs. TMFPPO is developed and incorporated into PVK to modulate the hole mobility and energy level of the hole-transport layer, giving rise to a barrier-free blue perovskite light-emitting diode and an enhancement of the EQE from 4.95 to 7.23% at 477 nm., Funding Agencies|National Research Foundation of Korea [NRF-2022H1D3A3A01077343, 2022R1A2C4002248, 2021M3H4A1A02049006]; Core Research Institute (CRI) program; National Research Foundation of Korea (NRF) [2022R1A6A1A03051158]; Samsung Research Funding amp; Incubation Centre of Samsung Electronics [SRFC-TC2103-04]; European Union [956270]; Linkoping University

Published
2023
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14. Controlling the interfacial dipole via functionalization of quinoxaline-based small molecules for electron transport layer in organic light emitting diodes.

Author

Lee, Seok Woo, Fan, Xiangyang, Whang, Dong Ryeol, Jang, Ji Won, Choi, Hyosung, Chang, Dong Wook, and Lee, Bo Ram

Subjects
ORGANIC light emitting diodes, ELECTRON transport, OPTOELECTRONIC devices, SMALL molecules, ORGANIC semiconductors, MOLECULAR magnetic moments, PHOSPHINE oxides, LIGHT emitting diodes
Abstract

Optoelectronic devices with organic semiconductors, such as organic light-emitting diodes (OLEDs), have received much attention because they offer ease of processing and device flexibility. However, practical application of these devices is still hindered by relatively poor device performance and lack of cost-effective fabrication process, which represent properties largely determined by the molecular dipole moments of the organic molecules. In this study, we designed and prepared novel quinoxaline-phosphine oxide small molecules (QPSMs) as the electron transport layer (ETL) for the solution-processable OLEDs by tuning the end functional group of the aromatic QPSMs. A key design criterion was controlling the dipole moments of QPSMs, which confers (1) convenient deposition on the emission layer without further annealing through solubility in isopropanol and (2) improved electron injection/transport behavior through effective band level matching of the devices. In particular, the optimized OLEDs with (4-(2,3-bis(4-methoxyphenyl)quinoxalin-5-yl)phenyl)diphenylphosphine oxide (MQxTPPO1) exhibit external quantum efficiency (EQE) of 6.12%. Our results demonstrate the potential application of QPSMs as next-generation ETLs in organic semiconductors. [ABSTRACT FROM AUTHOR]

Published
2023
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15. Phosphine oxide modulator-ameliorated hole injection for blue perovskite light-emitting diodes

Author

Fan, Xiangyang, primary, Wang, Yu, additional, Shen, Xinyu, additional, Yu, Zhongkai, additional, Jeong, Woo Hyeon, additional, Jang, Ji Won, additional, Kim, Yeong Gyeong, additional, Woo, Seung-Je, additional, Ahn, Hyungju, additional, Choi, Hyosung, additional, Lee, Tae-Woo, additional, Park, Sung Heum, additional, Gao, Feng, additional, and Lee, Bo Ram, additional

Published
2023
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17. A Universal Perovskite Nanocrystal Ink for High‐Performance Optoelectronic Devices

Author

Song, Hochan, primary, Yang, Jonghee, additional, Jeong, Woo Hyeon, additional, Lee, Jeongjae, additional, Lee, Tack Ho, additional, Yoon, Jung Won, additional, Lee, Hajin, additional, Ramadan, Alexandra J., additional, Oliver, Robert D. J., additional, Cho, Seong Chan, additional, Lim, Seul Gi, additional, Jang, Ji Won, additional, Yu, Zhongkai, additional, Oh, Jae Taek, additional, Jung, Eui Dae, additional, Song, Myoung Hoon, additional, Park, Sung Heum, additional, Durrant, James R., additional, Snaith, Henry J., additional, Lee, Sang Uck, additional, Lee, Bo Ram, additional, and Choi, Hyosung, additional

Published
2022
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23. A polymer/small-molecule binary-blend hole transport layer for enhancing charge balance in blue perovskite light emitting diodes

Author

Yu, Zhongkai, primary, Jeong, Woo Hyeon, additional, Kang, Keehoon, additional, Song, Hochan, additional, Shen, Xinyu, additional, Ahn, Hyungju, additional, Lee, Seok Woo, additional, Fan, Xiangyang, additional, Jang, Ji Won, additional, Ha, Su Ryong, additional, Min, Jeong Wan, additional, Park, Jong Hyun, additional, Han, Jongmin, additional, Jung, Eui Dae, additional, Song, Myoung Hoon, additional, Chang, Dong Wook, additional, Im, Won Bin, additional, Park, Sung Heum, additional, Choi, Hyosung, additional, and Lee, Bo Ram, additional

Published
2022
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25. Surface Oxidation of Cu 2 O Nanoparticles by Adsorbed Ammonia.

Author

Lee, Siwoo, Jang, Ji Won, and Ryu, Young Bok

Subjects
*COPPER oxide, *X-ray photoelectron spectroscopy, *INFRARED spectroscopy, *CUPROUS oxide, *AMMONIA, *NANOPARTICLES
Abstract

Copper-based nanoparticles have been intensively studied owing to their superior antibacterial activity. In this study, cuprous oxide (Cu2O) nanoparticles were synthesized using two different methods. In particular, two methods for synthesizing copper oxide from NaOH, namely, with and without the addition of NH3, were used to adjust the morphology of the nanoparticles. The nanoparticles from the NH3 and NaOH samples possessed an octahedral morphology. The crystal structure of the samples was confirmed by X-ray diffraction. The size distribution of the NH3 sample was narrower than that of the NaOH sample. Furthermore, the average size of the NH3 sample was smaller than that of the NaOH sample. Unexpectedly, the antibacterial activity of the NH3 sample was found to be lower than that of the NaOH sample. X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy revealed that the adsorbed NH3 caused the surface oxidation of Cu2O nanoparticles with azide (N3) formation on surface. [ABSTRACT FROM AUTHOR]

Published
2022
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28. Surface Activity and Emulsifying Effect of Non-Toxic Starch Nanocrystal

Author

Hwang, Young-Ha, primary, Cho, Kwan Hyung, additional, Kim, Hye-In, additional, Kim, Hee-Cheol, additional, Kim, Sung Tae, additional, Lee, Jeong Gi, additional, Cheon, Se Hyeop, additional, Choi, Se-Hee, additional, Park, Hye Jin, additional, Jang, Ji-Won, additional, Choi, Sung-Up, additional, Lee, Kooyeon, additional, Park, Sang Yeob, additional, and Jang, Dong-Jin, additional

Published
2021
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31. In situ cadmium surface passivation of perovskite nanocrystals for blue LEDs

Author

Jeong, Woo Hyeon, primary, Yu, Zhongkai, additional, Gregori, Luca, additional, Yang, Jonghee, additional, Ha, Su Ryong, additional, Jang, Ji Won, additional, Song, Hochan, additional, Park, Jong Hyun, additional, Jung, Eui Dae, additional, Song, Myoung Hoon, additional, Park, Sung Heum, additional, Snaith, Henry J., additional, Boretti, Alberto, additional, De Angelis, Filippo, additional, Meggiolaro, Daniele, additional, Lee, Jeongjae, additional, Choi, Hyosung, additional, and Lee, Bo Ram, additional

Published
2021
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35. A comparative study of effects of dietary mercuric chloride and methylmercury chloride on growth performance, tissue accumulation, stress and immune responses, and plasma measurements in Korean rockfish, Sebastes schlegeli

Author

Jang, Ji-Won, primary, Lee, Seunghyung, additional, Lee, Bong-Joo, additional, Hur, Sang-Woo, additional, Son, Maeng-Hyun, additional, Kim, Kang-Woong, additional, Kim, Kyoung-Duck, additional, and Han, Hyon-Sob, additional

Published
2020
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45. Sentiment Analysis Utilizing Modal Expressions

Author

Jee Eun Kim and Jang Ji-won

Subjects
Modal, business.industry, Computer science, Sentiment analysis, Immunology and Allergy, Artificial intelligence, computer.software_genre, business, computer, Natural language processing
Published
2017

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