Pub Date : 2021-09-30DOI: 10.5757/asct.2021.30.5.156
Guen Hyung Oh, Taewan Kim
Polymer electrolytes and ionic liquids (ILs) have attracted significant interest in applications as gate dielectrics. In this study, we fabricated top-gated molybdenum disulfide (MoS2) thin-film transistors using IL and ion-gel (IG) gate dielectrics. Room-temperature Raman spectra measurements indicated a dominant peak spectral emission at 358 cm−1 (E1 2g) and 406.44 cm−1 (A1g) associated with bilayer MoS2 films. The fabricated thin-film field-effect transistors (FET) with IG gate dielectric exhibited band transport with a highest mobility of 0.5 cm2/V⋅s, and a poor ION/IOFF ratio of ~10. By contrast, the FET with IL gate dielectric exhibited a 3400 % improvement in terms of the mobility (17.9 cm2/V⋅s), and a 1000 % improvement of the ION/IOFF ratio (~100).
{"title":"Comparison of Ionic Liquid and Ion-Gel Top-Gate MoS2 Field-Effect Transistors","authors":"Guen Hyung Oh, Taewan Kim","doi":"10.5757/asct.2021.30.5.156","DOIUrl":"https://doi.org/10.5757/asct.2021.30.5.156","url":null,"abstract":"Polymer electrolytes and ionic liquids (ILs) have attracted significant interest in applications as gate dielectrics. In this study, we fabricated top-gated molybdenum disulfide (MoS2) thin-film transistors using IL and ion-gel (IG) gate dielectrics. Room-temperature Raman spectra measurements indicated a dominant peak spectral emission at 358 cm−1 (E1 2g) and 406.44 cm−1 (A1g) associated with bilayer MoS2 films. The fabricated thin-film field-effect transistors (FET) with IG gate dielectric exhibited band transport with a highest mobility of 0.5 cm2/V⋅s, and a poor ION/IOFF ratio of ~10. By contrast, the FET with IL gate dielectric exhibited a 3400 % improvement in terms of the mobility (17.9 cm2/V⋅s), and a 1000 % improvement of the ION/IOFF ratio (~100).","PeriodicalId":8223,"journal":{"name":"Applied Science and Convergence Technology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81204703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.5757/asct.2021.30.5.137
Tae-Wook Kim, Gye-Young Jo, Soo-Min Lee, Kyu-Hang Lee, Yetang Jin, Byung-Koo Son
Perfluorinated compounds (PFCs), including sulfur hexafluoride (SF 6 ), are used as insulating gases for heavy electric equipment, and are green- house gases with a very high global warming potential. For the thermal decomposition of greenhouse gases, a high temperature of 3,000 K or more and a technology to prevent recombination of the decomposed gases are required. A direct current plasma arc with a flame temperature of 6,000 K or higher provides an effective ultra-high temperature for the decomposition of chemically stable PFCs. A large amount of CaO, which is a raw material for clinker, is in the cement kiln, hence the S and F radicals decomposed from SF 6 react with CaO to quickly convert it to CaF 2 and CaSO 4 and prevent their recombination. Therefore, the convergence technology of plasma and cement kiln is known as an effective method for treating PFCs. However, the interior of the cement kiln causes erosion of the plasma torch due to the turbulent flow of a large amount of combustion air at a high temperature of 1,500 ∘ C or more, and the scattering of the raw material particles of the clinker, which greatly affects the operation stability. In this study, a plasma torch was developed that can maintain stable plasma in a vulnerable environment and effectively decompose PFCs. Moreover, the design and results of the experiment on the torch were presented to enable stable plasma operation for a long time in vulnerable environmental conditions through durability, plasma efficiency, and analysis of the discharge characteristics. thermal efficiency, and durability of the plasma torch were analyzed. Continuous operation of the plasma torch for more than 1,000 h while maintaining the plasma characteristics even in en- vironments with a high temperature, vibration, and strong turbulent flow was verified using a molybdenum preserve nozzle. At this time, the plasma efficiency was measured as 79.1%, confirming the supe-rior durability and efficiency of the developed plasma torch to those of the conventional PFC treatment torch. These results show that the high-temperature plasma torch can be considered advanced technol- ogy with high utility in various waste gas treatment processes and plasma incineration fields by overcoming the short lifespan due to electrode erosion, which is a known disadvantage of high-temperature plasma torches.
{"title":"A Study on Direct Current Arc Plasma Torch Design with Preserve Nozzle for Perfluorinated Compounds (PFCs) Decomposition in Cement Kiln","authors":"Tae-Wook Kim, Gye-Young Jo, Soo-Min Lee, Kyu-Hang Lee, Yetang Jin, Byung-Koo Son","doi":"10.5757/asct.2021.30.5.137","DOIUrl":"https://doi.org/10.5757/asct.2021.30.5.137","url":null,"abstract":"Perfluorinated compounds (PFCs), including sulfur hexafluoride (SF 6 ), are used as insulating gases for heavy electric equipment, and are green- house gases with a very high global warming potential. For the thermal decomposition of greenhouse gases, a high temperature of 3,000 K or more and a technology to prevent recombination of the decomposed gases are required. A direct current plasma arc with a flame temperature of 6,000 K or higher provides an effective ultra-high temperature for the decomposition of chemically stable PFCs. A large amount of CaO, which is a raw material for clinker, is in the cement kiln, hence the S and F radicals decomposed from SF 6 react with CaO to quickly convert it to CaF 2 and CaSO 4 and prevent their recombination. Therefore, the convergence technology of plasma and cement kiln is known as an effective method for treating PFCs. However, the interior of the cement kiln causes erosion of the plasma torch due to the turbulent flow of a large amount of combustion air at a high temperature of 1,500 ∘ C or more, and the scattering of the raw material particles of the clinker, which greatly affects the operation stability. In this study, a plasma torch was developed that can maintain stable plasma in a vulnerable environment and effectively decompose PFCs. Moreover, the design and results of the experiment on the torch were presented to enable stable plasma operation for a long time in vulnerable environmental conditions through durability, plasma efficiency, and analysis of the discharge characteristics. thermal efficiency, and durability of the plasma torch were analyzed. Continuous operation of the plasma torch for more than 1,000 h while maintaining the plasma characteristics even in en- vironments with a high temperature, vibration, and strong turbulent flow was verified using a molybdenum preserve nozzle. At this time, the plasma efficiency was measured as 79.1%, confirming the supe-rior durability and efficiency of the developed plasma torch to those of the conventional PFC treatment torch. These results show that the high-temperature plasma torch can be considered advanced technol- ogy with high utility in various waste gas treatment processes and plasma incineration fields by overcoming the short lifespan due to electrode erosion, which is a known disadvantage of high-temperature plasma torches.","PeriodicalId":8223,"journal":{"name":"Applied Science and Convergence Technology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77686751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.5757/asct.2021.30.5.141
Jangjae Lee, C. Cho, M. Choi, Chang Seok Cho, T. J. Oh, Yong Shik Lee, J. Yim, Heung Cheol Yoo, Hee Soo Jung, S. You
In this experimental research, the characteristics of the discharge generated using a flexible electrode at intermediate pressure were investigated. We confirmed the discharge patterns according to the pulse width and frequency of a pulse generator with a fixed voltage under a pressure of 0.3 atm, which is the pressure at a typical flight altitude. Uniform discharge was found to occur at a frequency of 10 kHz with a pulse width of 4 μs and at a frequency of 20 kHz with a pulse width of 3 μs. To analyze the trend of discharge patterns, the voltage and current waveforms of the discharge in each condition were measured. In addition, the power dissipated by one cycle was calculated from the measured voltage and current waveforms. From the measurement and calculation results, it was confirmed that the dissipated power was large when the discharge occurred at a frequency of 20 kHz with a pulse width of 3 μs, that is, the brighter and more uniform discharge pattern, which was found to be the optimal discharge condition for the flexible electrode at a pressure of 0.3 atm.
{"title":"Experimental Study of Discharge with Flexible Electrodes at Intermediate Pressure for Radar Cross Section Reduction","authors":"Jangjae Lee, C. Cho, M. Choi, Chang Seok Cho, T. J. Oh, Yong Shik Lee, J. Yim, Heung Cheol Yoo, Hee Soo Jung, S. You","doi":"10.5757/asct.2021.30.5.141","DOIUrl":"https://doi.org/10.5757/asct.2021.30.5.141","url":null,"abstract":"In this experimental research, the characteristics of the discharge generated using a flexible electrode at intermediate pressure were investigated. We confirmed the discharge patterns according to the pulse width and frequency of a pulse generator with a fixed voltage under a pressure of 0.3 atm, which is the pressure at a typical flight altitude. Uniform discharge was found to occur at a frequency of 10 kHz with a pulse width of 4 μs and at a frequency of 20 kHz with a pulse width of 3 μs. To analyze the trend of discharge patterns, the voltage and current waveforms of the discharge in each condition were measured. In addition, the power dissipated by one cycle was calculated from the measured voltage and current waveforms. From the measurement and calculation results, it was confirmed that the dissipated power was large when the discharge occurred at a frequency of 20 kHz with a pulse width of 3 μs, that is, the brighter and more uniform discharge pattern, which was found to be the optimal discharge condition for the flexible electrode at a pressure of 0.3 atm.","PeriodicalId":8223,"journal":{"name":"Applied Science and Convergence Technology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78168385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-30DOI: 10.5757/asct.2021.30.4.102
Seung-Wan Yoo, C. Cho, Kyung Tae Kim, Hyo-Chang Lee, Shinjae You
Fluorocarbon (C 7 F 14 , C 7 F 8 ) plasmas are investigated to verify their etching characteristics as an alternative etchant of SiO 2 etch process because C 7 F 8 and C 7 F 14 precursors are expected to have low Global warming potentials. Comparing the etch results of C 4 F 8 , C 7 F 14 , and C 7 F 8 plasmas, C 7 F 8 provides the highest selectivity for etching SiO 2 at a moderate etching rate of the three fluorocarbons. C 4 F 8 and C 7 F 14 plasmas show similar magnitudes of selectivity at the same O 2 injection. O 2 addition is used to control densities of carbon species and optimize etching conditions. From comparison of the species existing in the C 4 F 8 , C 7 F 14 , and C 7 F 8 plasmas by the electron-emitting source, CF radicals and carbon atoms are important in determining the remarkable selectivity of C 7 F 8 plasma. This understanding is verified using X-ray photoelectron spectroscopy analysis.
{"title":"Characteristics of SiO2 Etching by Capacitively Coupled Plasma with Different Fluorocarbon Liquids (C7F14, C7F8) and Fluorocarbon Gas (C4F8)","authors":"Seung-Wan Yoo, C. Cho, Kyung Tae Kim, Hyo-Chang Lee, Shinjae You","doi":"10.5757/asct.2021.30.4.102","DOIUrl":"https://doi.org/10.5757/asct.2021.30.4.102","url":null,"abstract":"Fluorocarbon (C 7 F 14 , C 7 F 8 ) plasmas are investigated to verify their etching characteristics as an alternative etchant of SiO 2 etch process because C 7 F 8 and C 7 F 14 precursors are expected to have low Global warming potentials. Comparing the etch results of C 4 F 8 , C 7 F 14 , and C 7 F 8 plasmas, C 7 F 8 provides the highest selectivity for etching SiO 2 at a moderate etching rate of the three fluorocarbons. C 4 F 8 and C 7 F 14 plasmas show similar magnitudes of selectivity at the same O 2 injection. O 2 addition is used to control densities of carbon species and optimize etching conditions. From comparison of the species existing in the C 4 F 8 , C 7 F 14 , and C 7 F 8 plasmas by the electron-emitting source, CF radicals and carbon atoms are important in determining the remarkable selectivity of C 7 F 8 plasma. This understanding is verified using X-ray photoelectron spectroscopy analysis.","PeriodicalId":8223,"journal":{"name":"Applied Science and Convergence Technology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89216665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-30DOI: 10.5757/asct.2021.30.4.95
Intek Song
A new way to prepare single crystals of ligand-coordinated chromium (II) acetate with quadruple bonds is presented. Coordination of water and pyridine with crystal growth occur by seed-mediated growth. The product was obtained as crystals with well-defined facets. Raman spectroscopy confirmed the high quality and purity of the products. Mechanism studies showed that the growth reaction is driven by heterogeneous crystallization at the interface of the seeds. Seed-mediated growth results in the high quality and large size of the crystals with improved yield for shorter reaction time.
{"title":"Fast Synthesis of Ligand-Coordinated Chromium (II) Acetate with Quadruple Bonds by Seed-Mediated Growth","authors":"Intek Song","doi":"10.5757/asct.2021.30.4.95","DOIUrl":"https://doi.org/10.5757/asct.2021.30.4.95","url":null,"abstract":"A new way to prepare single crystals of ligand-coordinated chromium (II) acetate with quadruple bonds is presented. Coordination of water and pyridine with crystal growth occur by seed-mediated growth. The product was obtained as crystals with well-defined facets. Raman spectroscopy confirmed the high quality and purity of the products. Mechanism studies showed that the growth reaction is driven by heterogeneous crystallization at the interface of the seeds. Seed-mediated growth results in the high quality and large size of the crystals with improved yield for shorter reaction time.","PeriodicalId":8223,"journal":{"name":"Applied Science and Convergence Technology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72513085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-30DOI: 10.5757/asct.2021.30.4.98
Y. Kim
A Ba 0.9 Bi 0.1 TiO 3 solid solution was prepared by substituting 0.1 mole % Bi 2 O 3 at the Ba 2+ sites in BaTiO 3 , and its dielectric properties were investigated. The Ba 0 . 9 Bi 0 . 1 TiO 3 solid solution was sintered at 1310 ∘ C for 5 h. The stable formation of the perovskite structure was confirmed through X-ray diffraction, energy-dispersive X-ray spectroscopy, and field emission scanning electron microscopy. Unlike pure BaTiO 3 , pyrochlore Bi 2 Ti 2 O 7 was observed in Ba 0 . 9 Bi 0 . 1 TiO 3 at approximately 27.1 ∘ . Overall, the perovskite structure was well formed. The Ba 0 . 9 Bi 0 . 1 TiO 3 solid solution showed typical dielectric properties and followed the modified Curie–Weiss law. In addition, the curve of the dielectric constant vs. temperature showed an extremely gradual change compared to the phase transition behavior of BaTiO 3 .
{"title":"Influence of Bismuth Oxide on Dielectric Properties of Barium Titanate Solid Solution","authors":"Y. Kim","doi":"10.5757/asct.2021.30.4.98","DOIUrl":"https://doi.org/10.5757/asct.2021.30.4.98","url":null,"abstract":"A Ba 0.9 Bi 0.1 TiO 3 solid solution was prepared by substituting 0.1 mole % Bi 2 O 3 at the Ba 2+ sites in BaTiO 3 , and its dielectric properties were investigated. The Ba 0 . 9 Bi 0 . 1 TiO 3 solid solution was sintered at 1310 ∘ C for 5 h. The stable formation of the perovskite structure was confirmed through X-ray diffraction, energy-dispersive X-ray spectroscopy, and field emission scanning electron microscopy. Unlike pure BaTiO 3 , pyrochlore Bi 2 Ti 2 O 7 was observed in Ba 0 . 9 Bi 0 . 1 TiO 3 at approximately 27.1 ∘ . Overall, the perovskite structure was well formed. The Ba 0 . 9 Bi 0 . 1 TiO 3 solid solution showed typical dielectric properties and followed the modified Curie–Weiss law. In addition, the curve of the dielectric constant vs. temperature showed an extremely gradual change compared to the phase transition behavior of BaTiO 3 .","PeriodicalId":8223,"journal":{"name":"Applied Science and Convergence Technology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78754207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-30DOI: 10.5757/asct.2021.30.4.111
Kyung Ho Kim, Jaieun An, Jun-Seob Kim, Joonwon Bae, Oh Seok Kwon
In this study, a convenient high-performance portable sensor platform for simple, fast, and efficient detection of H1N1 virus is demonstrated using a graphene-based transistor type architecture. A uniform graphene layer was generated and patterned by conventional methods such as lithography and vapor deposition, subsequently, electrodes were introduced on the patterned graphene layer to obtain transistor type sensor geometry. Then, the graphene surface was functionalized with antibody for H1N1 virus detection and sensor performance test. The transition curve, linearity, and sensitivity (10 pfu/mL) of the sensor component were measured. In addition, the portable H1N1 diagnosis platform for simple, fast, and convenient virus detection was produced and demonstrated. Consequently, the sensor performance was maintained in the portable sensor platform compared with the graphene-based sensor component. This presented portable H1N1 diagnosis platform showed better performance than the lateral flow assay.
{"title":"Graphene Field-Effect Transistor Based High-Performance Wireless Portable Device for H1N1 Detection","authors":"Kyung Ho Kim, Jaieun An, Jun-Seob Kim, Joonwon Bae, Oh Seok Kwon","doi":"10.5757/asct.2021.30.4.111","DOIUrl":"https://doi.org/10.5757/asct.2021.30.4.111","url":null,"abstract":"In this study, a convenient high-performance portable sensor platform for simple, fast, and efficient detection of H1N1 virus is demonstrated using a graphene-based transistor type architecture. A uniform graphene layer was generated and patterned by conventional methods such as lithography and vapor deposition, subsequently, electrodes were introduced on the patterned graphene layer to obtain transistor type sensor geometry. Then, the graphene surface was functionalized with antibody for H1N1 virus detection and sensor performance test. The transition curve, linearity, and sensitivity (10 pfu/mL) of the sensor component were measured. In addition, the portable H1N1 diagnosis platform for simple, fast, and convenient virus detection was produced and demonstrated. Consequently, the sensor performance was maintained in the portable sensor platform compared with the graphene-based sensor component. This presented portable H1N1 diagnosis platform showed better performance than the lateral flow assay.","PeriodicalId":8223,"journal":{"name":"Applied Science and Convergence Technology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89290524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-30DOI: 10.5757/asct.2021.30.4.115
Hyun Sung Kim
In this study, Ru(bpy) 3 @ZIF-11 and Ru(bpy) 3 @ZIF-12 catalysts (bpy = 2,2 ′ ‐bipyridine) were synthesized by encapsulating [Ru(bpy) 3 ] 2+ in zeolitic imidazolate frameworks (ZIFs) ZIF-11 and ZIF-12, respectively, and their photocatalytic activities were compared. Samples of different composites were prepared from their powders, and their crystal morphologies and photocatalytic activities were evaluated by X-ray diffraction analysis and UV-visible absorption spectrometry. [Ru(bpy) 3 ] 2+ @ZIF-12 catalysts possessed excellent photocatalytic stability and exhibited a synergistic effect of [Ru(bpy) 3 ] 2+ and Co in the Ru(bpy) 3 @ZIF-12 composite, and efficient electron transfer from the [Ru(bpy) 3 ] 2+ moiety to the ZIF- 11 framework.
{"title":"Enhancement of Photocatalytic Activity of Tris (bipyridine) Ruthenium by Encapsulation in Zeolitic Imidazolate Framework-11 and 12","authors":"Hyun Sung Kim","doi":"10.5757/asct.2021.30.4.115","DOIUrl":"https://doi.org/10.5757/asct.2021.30.4.115","url":null,"abstract":"In this study, Ru(bpy) 3 @ZIF-11 and Ru(bpy) 3 @ZIF-12 catalysts (bpy = 2,2 ′ ‐bipyridine) were synthesized by encapsulating [Ru(bpy) 3 ] 2+ in zeolitic imidazolate frameworks (ZIFs) ZIF-11 and ZIF-12, respectively, and their photocatalytic activities were compared. Samples of different composites were prepared from their powders, and their crystal morphologies and photocatalytic activities were evaluated by X-ray diffraction analysis and UV-visible absorption spectrometry. [Ru(bpy) 3 ] 2+ @ZIF-12 catalysts possessed excellent photocatalytic stability and exhibited a synergistic effect of [Ru(bpy) 3 ] 2+ and Co in the Ru(bpy) 3 @ZIF-12 composite, and efficient electron transfer from the [Ru(bpy) 3 ] 2+ moiety to the ZIF- 11 framework.","PeriodicalId":8223,"journal":{"name":"Applied Science and Convergence Technology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81322672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-30DOI: 10.5757/asct.2021.30.4.107
Sangeun Cho, S. Noh, Hyungsang Kim, H. Im
Distinctive spectroscopic characteristics are observed in colloidal perovskite CsPbBr 3 quantum dot (QD) dispersed in octane doped with PPO. As the content of CsPbBr 3 -QD increases, the emission and the absorption energies decrease due to QD-cluster formed in case of the inter-QD distance smaller than diameter of QD. Spectroscopic evidences supporting QD-cluster are found in the Urbach energy and the carrier lifetime. Unusual absorption lines showing explicit QD dependence are observed in Fourier-transform infrared spectra, which is explained by vibrational modes of bound PPO hybridized with CsPbBr 3 -QD.
{"title":"Distinctive Spectroscopic Characteristics Observed in Colloidal Perovskite CsPbBr3 Quantum Dot","authors":"Sangeun Cho, S. Noh, Hyungsang Kim, H. Im","doi":"10.5757/asct.2021.30.4.107","DOIUrl":"https://doi.org/10.5757/asct.2021.30.4.107","url":null,"abstract":"Distinctive spectroscopic characteristics are observed in colloidal perovskite CsPbBr 3 quantum dot (QD) dispersed in octane doped with PPO. As the content of CsPbBr 3 -QD increases, the emission and the absorption energies decrease due to QD-cluster formed in case of the inter-QD distance smaller than diameter of QD. Spectroscopic evidences supporting QD-cluster are found in the Urbach energy and the carrier lifetime. Unusual absorption lines showing explicit QD dependence are observed in Fourier-transform infrared spectra, which is explained by vibrational modes of bound PPO hybridized with CsPbBr 3 -QD.","PeriodicalId":8223,"journal":{"name":"Applied Science and Convergence Technology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85960616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-31DOI: 10.5757/ASCT.2021.30.3.92
Ju-Hong Cha, Sang‐Woo Kim, Ho‐Jun Lee
In high current implantation, improving the ion extractability is a decisive factor contributing to the equipment efficiency and process cost reduction. A direct current filament ion source and inductively coupled plasma ion source were prepared to observe the degree of plasma extraction according to the ion source characteristics. The plasma parameters used to optimize beam extraction for the filament and RF discharges were 600 W, Ar 2 × 10 −5 Torr, and Ø200 × 250 mm discharge space. In the thermionic ion source, the ion density, electron temperature, and Bohm current density were 5 × 10 9 1/cm 3 , ≥ 6 eV, and ≈ 3.5 A/m 2 , respectively. In the RF ion source, the ion density, electron temperature, and Bohm current density were approximately 5 × 10 10 1/cm 3 , ≈ 3 ∼ 4 eV, and ≈ 25 A/m 2 , respectively. Optimization and analysis of ion extraction according to the plasma and accelerator parameters were calculated using IBSimu. The beam emittance, which is the most important parameter of the ion beam quality, was measured as the beam envelope onto the phase space by an ellipse. A change in the plasma meniscus shape was observed according to the plasma parameters in the ion source, and the emittance of the extracted ion beam was calculated according to the electrode gap distance and aperture structure.
{"title":"A Study on Beam Extraction Characteristics of RF and DC Filament Ion Source for High Current Ion Implanters","authors":"Ju-Hong Cha, Sang‐Woo Kim, Ho‐Jun Lee","doi":"10.5757/ASCT.2021.30.3.92","DOIUrl":"https://doi.org/10.5757/ASCT.2021.30.3.92","url":null,"abstract":"In high current implantation, improving the ion extractability is a decisive factor contributing to the equipment efficiency and process cost reduction. A direct current filament ion source and inductively coupled plasma ion source were prepared to observe the degree of plasma extraction according to the ion source characteristics. The plasma parameters used to optimize beam extraction for the filament and RF discharges were 600 W, Ar 2 × 10 −5 Torr, and Ø200 × 250 mm discharge space. In the thermionic ion source, the ion density, electron temperature, and Bohm current density were 5 × 10 9 1/cm 3 , ≥ 6 eV, and ≈ 3.5 A/m 2 , respectively. In the RF ion source, the ion density, electron temperature, and Bohm current density were approximately 5 × 10 10 1/cm 3 , ≈ 3 ∼ 4 eV, and ≈ 25 A/m 2 , respectively. Optimization and analysis of ion extraction according to the plasma and accelerator parameters were calculated using IBSimu. The beam emittance, which is the most important parameter of the ion beam quality, was measured as the beam envelope onto the phase space by an ellipse. A change in the plasma meniscus shape was observed according to the plasma parameters in the ion source, and the emittance of the extracted ion beam was calculated according to the electrode gap distance and aperture structure.","PeriodicalId":8223,"journal":{"name":"Applied Science and Convergence Technology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76541235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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