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Rocio Ponce Ortiz - One of the best experts on this subject based on the ideXlab platform.
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semi ladder Type bithiophene imide based all acceptor semiconductors synthesis structure property correlations and unipolar n Type Transistor performance
Journal of the American Chemical Society, 2018Co-Authors: Yingfeng Wang, Han Guo, Alexandra Harbuzaru, Mohammad Afsar Uddin, Shaohua Ling, Yumin Tang, Huiliang Sun, Iratxe Arrecheamarcos, Juan Lopez T Navarrete, Rocio Ponce OrtizAbstract:Development of high-performance unipolar n-Type organic semiconductors still remains as a great challenge. In this work, all-acceptor bithiophene imide-based ladder-Type small molecules BTIn and semiladder-Type homopolymers PBTIn (n = 1–5) were synthesized, and their structure–property correlations were studied in depth. It was found that Pd-catalyzed Stille coupling is superior to Ni-mediated Yamamoto coupling to produce polymers with higher molecular weight and improved polymer quality, thus leading to greatly increased electron mobility (μe). Due to their all-acceptor backbone, these polymers all exhibit unipolar n-Type transport in organic thin-film Transistors, accompanied by low off-currents (10–10–10–9 A), large on/off current ratios (106), and small threshold voltages (∼15–25 V). The highest μe, up to 3.71 cm2 V–1 s–1, is attained from PBTI1 with the shortest monomer unit. As the monomer size is extended, the μe drops by 2 orders to 0.014 cm2 V–1 s–1 for PBTI5. This monotonic decrease of μe was al...
Youngkyoo Kim - One of the best experts on this subject based on the ideXlab platform.
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broadband all polymer photoTransistors with nanostructured bulk heterojunction layers of nir sensing n Type and visible light sensing p Type polymers
Scientific Reports, 2015Co-Authors: Hyemi Han, Sungho Nam, Jooyeok Seo, Hwajeong Kim, Chulyeon Lee, D D C Bradley, Youngkyoo KimAbstract:We report ‘broadband light-sensing’ all-polymer photoTransistors with the nanostructured bulk heterojunction (BHJ) layers of visible (VIS) light-sensing electron-donating (p-Type) polymer and near infrared (NIR) light-sensing electron-accepting (n-Type) polymer. Poly[{2,5-bis-(2-ethylhexyl)-3,6-bis-(thien-2-yl)-pyrrolo[3,4-c]pyrrole-1,4-diyl}-co-{2,2′-(2,1,3-benzothiadiazole)]-5,5′-diyl}] (PEHTPPD-BT), which is synthesized via Suzuki coupling and employed as the n-Type polymer, shows strong optical absorption in the NIR region (up to 1100 nm) in the presence of weak absorption in the VIS range (400 ~ 600 nm). To strengthen the VIS absorption, poly(3-hexylthiophene) (P3HT) is introduced as the p-Type polymer. All-polymer photoTransistors with the BHJ (P3HT:PEHTPPD-BT) layers, featuring a peculiar nano-domain morphology, exhibit typical p-Type Transistor characteristics and efficiently detect broadband (VIS ~ NIR) lights. The maximum corrected responsivity (without contribution of dark current) reaches up to 85 ~ 88% (VIS) and 26 ~ 40% (NIR) of theoretical responsivity. The charge separation process between P3HT and PEHTPPD-BT components in the highest occupied molecular orbital is proposed as a major working mechanism for the effective NIR sensing.
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liquid crystal gated organic field effect Transistors with in plane drain source gate electrode structure
ACS Applied Materials & Interfaces, 2015Co-Authors: Jooyeok Seo, Sungho Nam, Jaehoon Jeong, Hwajeong Kim, Chulyeon Lee, Youngkyoo KimAbstract:We report planar liquid crystal-gated-organic field-effect Transistors (LC-g-OFETs) with a simple in-plane drain–source–gate electrode structure, which can be cost-effectively prepared by typical photolithography/etching processes. The LC-g-OFET devices were fabricated by forming the LC layer (4-cyano-4′-pentylbiphenyl, 5CB) on top of the channel layer (poly(3-hexylthiophene), P3HT) that was spin-coated on the patterned indium–tin oxide (ITO)-coated glass substrates. The LC-g-OFET devices showed p-Type Transistor characteristics, while a current saturation behavior in the output curves was achieved for the 50–150 nm-thick P3HT (channel) layers. A prospective on/off ratio (>1 × 103) was obtained regardless of the P3HT thickness, whereas the resulting hole mobility (0.5–1.1 cm2/(V s)) at a linear regime was dependent on the P3HT thickness. The tilted ordering of 5CB at the LC-P3HT interfaces, which is induced by the gate electric field, has been proposed as a core point of working mechanism for the present ...
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hybrid photoTransistors based on bulk heterojunction films of poly 3 hexylthiophene and zinc oxide nanoparticle
ACS Applied Materials & Interfaces, 2013Co-Authors: Sungho Nam, Jooyeok Seo, Soohyeong Park, Sooyong Lee, Jaehoon Jeong, Hyena Lee, Hwajeong Kim, Youngkyoo KimAbstract:Hybrid photoTransistors (HPTRs) were fabricated on glass substrates using organic/inorganic hybrid bulk heterojunction films of p-Type poly(3-hexylthiophene) (P3HT) and n-Type zinc oxide nanoparticles (ZnONP). The content of ZnONP was varied up to 50 wt % in order to understand the composition effect of ZnONP on the performance of HPTRs. The morphology and nanostructure of the P3HT:ZnONP films was examined by employing high resolution electron microscopes and synchrotron radiation grazing angle X-ray diffraction system. The incident light intensity (PIN) was varied up to 43.6 μW/cm2, whereas three major wavelengths (525 nm, 555 nm, 605 nm) corresponded to the optical absorption of P3HT were applied. Results showed that the present HPTRs showed typical p-Type Transistor performance even though the n-Type ZnONP content increased up to 50 wt %. The highest Transistor performance was obtained at 50 wt %, whereas the lowest performance was measured at 23 wt % because of the immature bulk heterojunction morphol...
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organic photoTransistors with nanoscale phase separated polymer polymer bulk heterojunction layers
Nanoscale, 2011Co-Authors: Hyemin Hwang, Sungho Nam, Hwajeong Kim, D D C Bradley, Youngkyoo KimAbstract:Low-cost detectors for sensing photons at a low light intensity are of crucial importance in modern science. PhotoTransistors can deliver better signals of low-intensity light by electrical amplification, but conventional inorganic photoTransistors have a limitation owing to their high temperature processes in vacuum. In this work, we demonstrate organic photoTransistors with polymer/polymer bulk heterojunction blend films (mixtures of p-Type and n-Type semiconducting polymers), which can be fabricated by inexpensive solution processes at room temperature. The key idea here is to effectively exploit hole charges (from p-Type polymer) as major signaling carriers by employing p-Type Transistor geometry, while the n-Type polymer helps efficient charge separation from excitons generated by incoming photons. Results showed that the present organic Transistors exhibited proper functions as p-Type photoTransistors with ∼4.3 A W−1 responsivity at a low light intensity (1 µW cm−2), which supports their encouraging potential to replace conventional cooled charge coupled devices (CCD) for low-intensity light detection applications.
Yingfeng Wang - One of the best experts on this subject based on the ideXlab platform.
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semi ladder Type bithiophene imide based all acceptor semiconductors synthesis structure property correlations and unipolar n Type Transistor performance
Journal of the American Chemical Society, 2018Co-Authors: Yingfeng Wang, Han Guo, Alexandra Harbuzaru, Mohammad Afsar Uddin, Shaohua Ling, Yumin Tang, Huiliang Sun, Iratxe Arrecheamarcos, Juan Lopez T Navarrete, Rocio Ponce OrtizAbstract:Development of high-performance unipolar n-Type organic semiconductors still remains as a great challenge. In this work, all-acceptor bithiophene imide-based ladder-Type small molecules BTIn and semiladder-Type homopolymers PBTIn (n = 1–5) were synthesized, and their structure–property correlations were studied in depth. It was found that Pd-catalyzed Stille coupling is superior to Ni-mediated Yamamoto coupling to produce polymers with higher molecular weight and improved polymer quality, thus leading to greatly increased electron mobility (μe). Due to their all-acceptor backbone, these polymers all exhibit unipolar n-Type transport in organic thin-film Transistors, accompanied by low off-currents (10–10–10–9 A), large on/off current ratios (106), and small threshold voltages (∼15–25 V). The highest μe, up to 3.71 cm2 V–1 s–1, is attained from PBTI1 with the shortest monomer unit. As the monomer size is extended, the μe drops by 2 orders to 0.014 cm2 V–1 s–1 for PBTI5. This monotonic decrease of μe was al...
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(Semi)ladder-Type Bithiophene Imide-Based All-Acceptor Semiconductors: Synthesis, Structure–Property Correlations, and Unipolar n‑Type Transistor Performance
2018Co-Authors: Yingfeng Wang, Han Guo, Alexandra Harbuzaru, Mohammad Afsar Uddin, Iratxe Arrechea-marcos, Shaohua Ling, Yumin Tang, Huiliang Sun, Juan Teodomiro López NavarreteAbstract:Development of high-performance unipolar n-Type organic semiconductors still remains as a great challenge. In this work, all-acceptor bithiophene imide-based ladder-Type small molecules BTIn and semiladder-Type homopolymers PBTIn (n = 1–5) were synthesized, and their structure–property correlations were studied in depth. It was found that Pd-catalyzed Stille coupling is superior to Ni-mediated Yamamoto coupling to produce polymers with higher molecular weight and improved polymer quality, thus leading to greatly increased electron mobility (μe). Due to their all-acceptor backbone, these polymers all exhibit unipolar n-Type transport in organic thin-film Transistors, accompanied by low off-currents (10–10–10–9 A), large on/off current ratios (106), and small threshold voltages (∼15–25 V). The highest μe, up to 3.71 cm2 V–1 s–1, is attained from PBTI1 with the shortest monomer unit. As the monomer size is extended, the μe drops by 2 orders to 0.014 cm2 V–1 s–1 for PBTI5. This monotonic decrease of μe was also observed in their homologous BTIn small molecules. This trend of mobility decrease is in good agreement with the evolvement of disordered phases within the film, as revealed by Raman spectroscopy and X-ray diffraction measurements. The extension of the ladder-Type building blocks appears to have a large impact on the motion freedom of the building blocks and the polymer chains during film formation, thus negatively affecting film morphology and charge carrier mobility. The result indicates that synthesizing building blocks with more extended ladder-Type backbone does not necessarily lead to improved mobilities. This study marks a significant advance in the performance of all-acceptor-Type polymers as unipolar electron transporting materials and provides useful guidelines for further development of (semi)ladder-Type molecular and polymeric semiconductors for applications in organic electronics
Tsuyoshi Michinobu - One of the best experts on this subject based on the ideXlab platform.
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significant improvement of unipolar n Type Transistor performances by manipulating the coplanar backbone conformation of electron deficient polymers via hydrogen bonding
Journal of the American Chemical Society, 2019Co-Authors: Yang Wang, Tsukasa Hasegawa, Hidetoshi Matsumoto, Tsuyoshi MichinobuAbstract:The development of high-performance unipolar n-Type semiconducting polymers still remains a significant challenge. Only a few examples exhibit a unipolar electron mobility over 5 cm2 V–1 s–1. In th...
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Significant Improvement of Unipolar n‑Type Transistor Performances by Manipulating the Coplanar Backbone Conformation of Electron-Deficient Polymers via Hydrogen Bonding
2019Co-Authors: Yang Wang, Tsukasa Hasegawa, Hidetoshi Matsumoto, Tsuyoshi MichinobuAbstract:The development of high-performance unipolar n-Type semiconducting polymers still remains a significant challenge. Only a few examples exhibit a unipolar electron mobility over 5 cm2 V–1 s–1. In this study, a series of new poly(benzothiadiazole-naphthalenediimide) derivatives with a high unipolar electron mobility (μe) up to 7.16 cm2 V–1 s–1 in thin-film Transistors are reported. The dramatically increased μe is achieved by finely optimizing the coplanar backbone conformation through the introduction of vinylene bridges, which can form intramolecular hydrogen bonds with the neighboring fluorine and oxygen atoms. The hydrogen-bonding functionalities are fused to the backbone to ensure a much more planar conformation of the conjugated π-system, as demonstrated by the density functional theory (DFT)-based calculations. The theoretical prediction is in good agreement with the experimental results. As the coplanarity is promoted by the hydrogen bonding, the thin-film crystallinity and molecular packing strength are also improved, which is evidenced by the synchrotron two-dimensional grazing-incidence wide-angle X-ray scattering (GIWAXS) and atomic force microscopy (AFM) measurements. Notably, the GIWAXS measurements reveal an extremely short π–π stacking distance of 3.40 Å. Overall, this study marks a significant advance in the unipolar n-Type semiconducting polymers and offers a general approach for further increasing the electron mobility of semiconducting polymers in organic electronics
Hiroshi Katagiri - One of the best experts on this subject based on the ideXlab platform.
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terazulene isomers polarity change of ofets through molecular orbital distribution contrast
Journal of the American Chemical Society, 2016Co-Authors: Yuji Yamaguchi, Maki Takubo, Keisuke Ogawa, Ken-ichi Nakayama, Tomoyuki Koganezawa, Hiroshi KatagiriAbstract:Intermolecular orbital coupling is fundamentally important to organic semiconductor performance. Recently, we reported that 2,6′:2′,6″-terazulene (TAz1) exhibited excellent performance as an n-Type organic field-effect Transistor (OFET) via molecular orbital distribution control. To validate and develop this concept, here we present three other terazulene regioisomers, which have three azulene molecules connected at the 2- or 6-position along the long axis of the azulene, thus constructing a linear expanded π-conjugation system: 2,2′:6′,2″-terazulene (TAz2), 2,2′:6′,6″-terazulene (TAz3), and 6,2′:6′,6″-terazulene (TAz4). TAz2 and TAz3 exhibit ambipolar characteristics; TAz4 exhibits clear n-Type Transistor behavior as an OFET. The lowest unoccupied molecular orbitals (LUMOs) of all terazulenes are fully delocalized over the entire molecule. In contrast, the highest occupied molecular orbitals (HOMOs) of TAz2 and TAz3 are delocalized over the 2,2′-biazulene units; the HOMOs of TAz4 are localized at one end...
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Terazulene Isomers: Polarity Change of OFETs through Molecular Orbital Distribution Contrast
2016Co-Authors: Yuji Yamaguchi, Maki Takubo, Keisuke Ogawa, Ken-ichi Nakayama, Tomoyuki Koganezawa, Hiroshi KatagiriAbstract:Intermolecular orbital coupling is fundamentally important to organic semiconductor performance. Recently, we reported that 2,6′:2′,6″-terazulene (TAz1) exhibited excellent performance as an n-Type organic field-effect Transistor (OFET) via molecular orbital distribution control. To validate and develop this concept, here we present three other terazulene regioisomers, which have three azulene molecules connected at the 2- or 6-position along the long axis of the azulene, thus constructing a linear expanded π-conjugation system: 2,2′:6′,2″-terazulene (TAz2), 2,2′:6′,6″-terazulene (TAz3), and 6,2′:6′,6″-terazulene (TAz4). TAz2 and TAz3 exhibit ambipolar characteristics; TAz4 exhibits clear n-Type Transistor behavior as an OFET. The lowest unoccupied molecular orbitals (LUMOs) of all terazulenes are fully delocalized over the entire molecule. In contrast, the highest occupied molecular orbitals (HOMOs) of TAz2 and TAz3 are delocalized over the 2,2′-biazulene units; the HOMOs of TAz4 are localized at one end of the azulene unit. These findings confirm that terazulene isomers which are simple hydrocarbon compounds are versatile materials with a tunable-polarity FET characteristic that depends on the direction of the azulene unit and the related contrast of the molecular orbital distribution in the terazulene backbone
