Il Jeon - Academia.edu (original) (raw)
Papers by Il Jeon
Chemical communications (Cambridge, England), Jan 14, 2016
C70 multiadducts with a novel 1,2,3,4,41,56,57,58-configuration were prepared via oxazolination a... more C70 multiadducts with a novel 1,2,3,4,41,56,57,58-configuration were prepared via oxazolination and benzylation reactions. The structures of the adducts were determined by single crystal X-ray diffraction and spectral characterization. The compounds exhibit a high LUMO level, and result in a high open-circuit voltage in devices with P3HT.
Chemistry, an Asian journal, Jan 3, 2016
We demonstrated the application of 58-π electron 1,4-bis(silylmethyl)[60]fullerene derivatives, C... more We demonstrated the application of 58-π electron 1,4-bis(silylmethyl)[60]fullerene derivatives, C60(CH2SiMe2Ph)(CH2SiMe2Ar) (Ar = Ph and 2-methoxylphenyl for SIMEF-1 and SIMEF-2), in small molecule organic solar cells using a diketopyrrolopyrrole donor (DPP(TBFu)2). With the 58-π silylmethyl fullerene acceptor, SIMEF-1, devices showed an efficiency of 4.57%. They manifested improved open-circuit voltage (1.03 V) due to the lowest unoccupied molecular orbital level of SIMEF-1 being higher, while maintaining high short-circuit density (9.91 mA/cm2) through controlling the crystallinity of DPP by thermal treatment. On the other hand, despite even higher open-circuit voltage (1.05 V), SIMEF-2-based devices showed lower performance of 3.53%, due to low short-circuit current density (8.33 mA/cm2) and fill factor (0.40) arising from its asymmetric structure, lower mobility, and poor miscibility with the DPP electron donor molecule.
Nano letters, 2015
In this work, we fabricated indium-free perovskite solar cells (SCs) using direct- and dry-transf... more In this work, we fabricated indium-free perovskite solar cells (SCs) using direct- and dry-transferred aerosol single-walled carbon nanotube (SWNT). We investigated diverse methodologies to solve SWNT's hydrophobicity and doping issues in SC devices. These include changing wettability of poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS), MoO3 thermal doping, and HNO3(aq) doping with various dilutions from 15 to 70 v/v% to minimize its instability and toxic nature. We discovered that isopropanol (IPA) modified PEDOT:PSS works better than surfactant modified PEDOT:PSS as an electrode in perovskite SCs due to superior wettability, while MoO3 is not compatible owing to energy level mismatching. Diluted HNO3 (35 v/v%)-doped SWCNT-based device performed the highest PCE of 6.32% among SWNT-based perovskite SCs, which is 70% of an indium tin oxide (ITO)-based device (9.05%). Its flexible application showed 5.38% on a polyethylene terephthalate (PET) substrate.
Journal of the Optical Society of Korea
In this paper, we identify an intractable problem known as light leakage, which is more critical ... more In this paper, we identify an intractable problem known as light leakage, which is more critical in IPS mode compared to VA mode, and we propose diverse ways of tackling this issue. In general, the light leakage phenomenon arises from the stress generated by the bending of the LCD panel. This paper proposes three processing methods for reducing the mechanical stress causing LCD panel bending and light leakage. Changes in the lamination process of polarizer films and the application of a buffer layer can reduce the bending level by 32% and 21%, respectively. The combination of polarizer films according to variation of thickness also help to reduce the panel bending. In particular, it is important that a combination of these proposed modifications could provide the better solution to reduce the panel bending. From a geometric solution to a change in materials, the whole history of IPS light leakage solutions is presented succinctly. With this paper-or review, to be more precise-the me...
Journal of the American Chemical Society, Jan 19, 2015
Organic solar cells have been regarded as a promising electrical energy source. Transparent and c... more Organic solar cells have been regarded as a promising electrical energy source. Transparent and conductive carbon nanotube film offers an alternative to commonly used ITO in photovoltaics with superior flexibility. This communication reports carbon nanotube-based indium-free organic solar cells and their flexible application. Direct and dry deposited carbon nanotube film doped with MoOx functions as an electron-blocking transparent electrode, and its performance is enhanced further by overcoating with PEDOT:PSS. The single-walled carbon nanotube organic solar cell in this work shows a power conversion efficiency of 6.04%. This value is 83% of the leading ITO-based device performance (7.48%). Flexible application shows 3.91% efficiency and is capable of withstanding a severe cyclic flex test.
Inverted type organic solar cells have been regarded more promising over normal type, owing to a ... more Inverted type organic solar cells have been regarded more promising over normal type, owing to a favorable vertical phase separation and air-processability. Many techniques, such as thermal or solvent annealing, slow growth method, melting bi-layers etc. have been employed to improve the morphology of photoactive layer, which is one of the advantages of inverted type OSCs. As a result, the device per- formance is greatly enhanced which is also reflected in the current-density versus voltage curve. However, some of the methods presented above are difficult and costly to perform. In addition, inverted OSCs still employ certain metal oxide electron-transporting layers, which impose UV activation time due to light-soaking effect. Here we show a facile method that can control the vertical phase separation as well as minimize the light-soaking effect. By leaving the photoactive solution with a low volatile solvent in air before spin coating, conductive polymers (donor) and fullerene derivatives (acceptor) were separated vertically in a way that their charge extraction is enhanced. Besides, oxygen and impurities at the contact on ETL were removed by leaving the solution for a certain period. Mechanisms of these improvements were evidenced by various analytical techniques and empirical tests using different materials in different environments. We anticipate this finding can expedite the OSC research and its usage in all air-processed inverted OSCs.

We demonstrate the deposition of multilayered MoS2 on a low-cost metallic-semiconduct- ing carbon... more We demonstrate the deposition of multilayered MoS2 on a low-cost metallic-semiconduct- ing carbon nanotube via chemical vapor deposition, and the use of this material as electron acceptor species forming a bulk heterojunction with P3HT in inverted-type organic photovoltaics (OPVs). This is an uplifting discovery, in which MoS2 has been used as an electron acceptor in spite of its innate immiscibility with organic compounds. This is possible because we utilize carbon nanotube’s nature to intercalate with P3HT through p–p interaction. The successful binding of MoS2 onto carbon nanotube bundles and its optoelectronic effect as a photovoltaic device has been lucidly analyzed through various techniques in this paper. The effect has been ultimately evidenced by a power conversion efficiency of 0.46%, which proves MoS2 with many advantages can also be used as a photoactive layer.
Applied Optics, 2013
Glass bending in LCD displays is an inherent problem that has challenged many engineers. As a sol... more Glass bending in LCD displays is an inherent problem that has challenged many engineers. As a solution to this problem, we propose a methodology that can tackle the root of the phenomenon in terms of linear elastic beam theory. Using this hypothesis, we devised a background theory and a solution. In this paper, we present a glass panel to which geometrical changes, such as furrow, groove, and curb have been applied. These geometrical changes are applied to the nonactive area of the glass panel. To confirm the validity of our approach, we conducted simulation tests as well as hands-on experiments to observe the thermo-mechanical behavior of the device under various conditions. The simulation results using the Ansys simulator show that the proposed technique can reduce the deformation level of panel bending by 40%. In the experiment using a bare cell with polarizer films attached and with performing the high temperature reliability test, the deformation level of panel bending is reduced by half compared to the reference glass panel without any geometric alteration.
Japanese Journal of Applied Physics, 2009
![Research paper thumbnail of Mixture of [60] and [70]PCBM giving morphological stability in organic solar cells](https://attachments.academia-assets.com/46212657/thumbnails/1.jpg)
](Applied Physics Letters, 2013
Chemical communications (Cambridge, England), Jan 14, 2016
C70 multiadducts with a novel 1,2,3,4,41,56,57,58-configuration were prepared via oxazolination a... more C70 multiadducts with a novel 1,2,3,4,41,56,57,58-configuration were prepared via oxazolination and benzylation reactions. The structures of the adducts were determined by single crystal X-ray diffraction and spectral characterization. The compounds exhibit a high LUMO level, and result in a high open-circuit voltage in devices with P3HT.
Chemistry, an Asian journal, Jan 3, 2016
We demonstrated the application of 58-π electron 1,4-bis(silylmethyl)[60]fullerene derivatives, C... more We demonstrated the application of 58-π electron 1,4-bis(silylmethyl)[60]fullerene derivatives, C60(CH2SiMe2Ph)(CH2SiMe2Ar) (Ar = Ph and 2-methoxylphenyl for SIMEF-1 and SIMEF-2), in small molecule organic solar cells using a diketopyrrolopyrrole donor (DPP(TBFu)2). With the 58-π silylmethyl fullerene acceptor, SIMEF-1, devices showed an efficiency of 4.57%. They manifested improved open-circuit voltage (1.03 V) due to the lowest unoccupied molecular orbital level of SIMEF-1 being higher, while maintaining high short-circuit density (9.91 mA/cm2) through controlling the crystallinity of DPP by thermal treatment. On the other hand, despite even higher open-circuit voltage (1.05 V), SIMEF-2-based devices showed lower performance of 3.53%, due to low short-circuit current density (8.33 mA/cm2) and fill factor (0.40) arising from its asymmetric structure, lower mobility, and poor miscibility with the DPP electron donor molecule.
Nano letters, 2015
In this work, we fabricated indium-free perovskite solar cells (SCs) using direct- and dry-transf... more In this work, we fabricated indium-free perovskite solar cells (SCs) using direct- and dry-transferred aerosol single-walled carbon nanotube (SWNT). We investigated diverse methodologies to solve SWNT's hydrophobicity and doping issues in SC devices. These include changing wettability of poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS), MoO3 thermal doping, and HNO3(aq) doping with various dilutions from 15 to 70 v/v% to minimize its instability and toxic nature. We discovered that isopropanol (IPA) modified PEDOT:PSS works better than surfactant modified PEDOT:PSS as an electrode in perovskite SCs due to superior wettability, while MoO3 is not compatible owing to energy level mismatching. Diluted HNO3 (35 v/v%)-doped SWCNT-based device performed the highest PCE of 6.32% among SWNT-based perovskite SCs, which is 70% of an indium tin oxide (ITO)-based device (9.05%). Its flexible application showed 5.38% on a polyethylene terephthalate (PET) substrate.
Journal of the Optical Society of Korea
In this paper, we identify an intractable problem known as light leakage, which is more critical ... more In this paper, we identify an intractable problem known as light leakage, which is more critical in IPS mode compared to VA mode, and we propose diverse ways of tackling this issue. In general, the light leakage phenomenon arises from the stress generated by the bending of the LCD panel. This paper proposes three processing methods for reducing the mechanical stress causing LCD panel bending and light leakage. Changes in the lamination process of polarizer films and the application of a buffer layer can reduce the bending level by 32% and 21%, respectively. The combination of polarizer films according to variation of thickness also help to reduce the panel bending. In particular, it is important that a combination of these proposed modifications could provide the better solution to reduce the panel bending. From a geometric solution to a change in materials, the whole history of IPS light leakage solutions is presented succinctly. With this paper-or review, to be more precise-the me...
Journal of the American Chemical Society, Jan 19, 2015
Organic solar cells have been regarded as a promising electrical energy source. Transparent and c... more Organic solar cells have been regarded as a promising electrical energy source. Transparent and conductive carbon nanotube film offers an alternative to commonly used ITO in photovoltaics with superior flexibility. This communication reports carbon nanotube-based indium-free organic solar cells and their flexible application. Direct and dry deposited carbon nanotube film doped with MoOx functions as an electron-blocking transparent electrode, and its performance is enhanced further by overcoating with PEDOT:PSS. The single-walled carbon nanotube organic solar cell in this work shows a power conversion efficiency of 6.04%. This value is 83% of the leading ITO-based device performance (7.48%). Flexible application shows 3.91% efficiency and is capable of withstanding a severe cyclic flex test.
Inverted type organic solar cells have been regarded more promising over normal type, owing to a ... more Inverted type organic solar cells have been regarded more promising over normal type, owing to a favorable vertical phase separation and air-processability. Many techniques, such as thermal or solvent annealing, slow growth method, melting bi-layers etc. have been employed to improve the morphology of photoactive layer, which is one of the advantages of inverted type OSCs. As a result, the device per- formance is greatly enhanced which is also reflected in the current-density versus voltage curve. However, some of the methods presented above are difficult and costly to perform. In addition, inverted OSCs still employ certain metal oxide electron-transporting layers, which impose UV activation time due to light-soaking effect. Here we show a facile method that can control the vertical phase separation as well as minimize the light-soaking effect. By leaving the photoactive solution with a low volatile solvent in air before spin coating, conductive polymers (donor) and fullerene derivatives (acceptor) were separated vertically in a way that their charge extraction is enhanced. Besides, oxygen and impurities at the contact on ETL were removed by leaving the solution for a certain period. Mechanisms of these improvements were evidenced by various analytical techniques and empirical tests using different materials in different environments. We anticipate this finding can expedite the OSC research and its usage in all air-processed inverted OSCs.

We demonstrate the deposition of multilayered MoS2 on a low-cost metallic-semiconduct- ing carbon... more We demonstrate the deposition of multilayered MoS2 on a low-cost metallic-semiconduct- ing carbon nanotube via chemical vapor deposition, and the use of this material as electron acceptor species forming a bulk heterojunction with P3HT in inverted-type organic photovoltaics (OPVs). This is an uplifting discovery, in which MoS2 has been used as an electron acceptor in spite of its innate immiscibility with organic compounds. This is possible because we utilize carbon nanotube’s nature to intercalate with P3HT through p–p interaction. The successful binding of MoS2 onto carbon nanotube bundles and its optoelectronic effect as a photovoltaic device has been lucidly analyzed through various techniques in this paper. The effect has been ultimately evidenced by a power conversion efficiency of 0.46%, which proves MoS2 with many advantages can also be used as a photoactive layer.
Applied Optics, 2013
Glass bending in LCD displays is an inherent problem that has challenged many engineers. As a sol... more Glass bending in LCD displays is an inherent problem that has challenged many engineers. As a solution to this problem, we propose a methodology that can tackle the root of the phenomenon in terms of linear elastic beam theory. Using this hypothesis, we devised a background theory and a solution. In this paper, we present a glass panel to which geometrical changes, such as furrow, groove, and curb have been applied. These geometrical changes are applied to the nonactive area of the glass panel. To confirm the validity of our approach, we conducted simulation tests as well as hands-on experiments to observe the thermo-mechanical behavior of the device under various conditions. The simulation results using the Ansys simulator show that the proposed technique can reduce the deformation level of panel bending by 40%. In the experiment using a bare cell with polarizer films attached and with performing the high temperature reliability test, the deformation level of panel bending is reduced by half compared to the reference glass panel without any geometric alteration.
Japanese Journal of Applied Physics, 2009
Applied Physics Letters, 2013