1. Ono S.; Mikie T.; Nakano K.; Tajima K.; Osaka I.; Two Isomeric Benzo[d]imidazole-Based Nonfullerene Acceptors for Organic Photovoltaics, ACS Appl. Energy. Mater., 2024, 7, 2946-2954. DOI
  2. Chou L.-H.; Chen F.; Nakano K.; Yamanaka K.; Mikie T.; Saito M.; Liu C.-L.; Tajima K.; Osaka I.; Bending the Rule: Naphthobisthiadiazole-Based Terpolymers with Both High Solubility and Crystallinity for Organic Photovoltaics, ACS Appl. Polym. Mater., 2024, 14, 2586-2593. DOI
  3. Xiong S.; Fukuda K.; Nakano K.; Lee S.; Sumi Y.; Takakuwa M.; Inoue D.; Hashizume D.; Du B.; Yokota T.; Zhou Y.; Tajima K.; Someya T.; Waterproof and Ultraflexible Organic Photovoltaics with Improved Interface Adhesion, Nature Commun., 2024, 15, 681. DOI


  1. Sugie A.; Nakano K.; Tajima K.; Osaka I.; Yoshida Y.; Dependence of Exciton Binding Energy on Bandgap of Organic Semiconductors, J. Phys. Chem. Lett., 2023, 14, 11412-11420. DOI
  2. Nakano K.; Kaji Y.; Tajima K.; Origin of Electric Field-dependent Charge Generation in Organic Photovoltaics with Planar and Bulk Heterojunctions, J. Mater. Chem. A, 2023, 11, 26499-26507. DOI
  3. Nakano K.; Leong I. W.; Hashizume D.; Bulgarevich K.; Takimiya K.; Nishiyama Y.; Yamazaki T.; Tajima K.; Synthesis of 3,3′-Dihydroxy-2,2′-diindan-1,1′-dione Derivatives for Tautomeric Organic Semiconductors Exhibiting Intramolecular Double Proton Transfer, Chem. Sci., 2023, 14, 12205-12218. DOI
  4. Wang W.-C.; Nakano K.; Tanaka Y.; Kurihara K.; Ishii H.; Adachi K.; Hashizume D.; Hsu C.-S.; Tajima K.; Stable Spontaneous Orientation Polarization by Widening the Optical Band Gap with 1,3,5,7-Tetrakis(1-phenyl-1H-benzo[d]imidazol-2-yl)adamantane, J. Mater. Chem. C, 2023, 11, 13039-13046. DOI
  5. Liu W.; Hu S.; Pascual J.; Nakano K.; Murdey R.; Tajima K.; Wakamiya A.; Tin Halide Perovskite Solar Cells with Open-Circuit Voltages Approaching the Shockley–Queisser Limit, ACS Appl. Mater. Interfaces, 2023, 15, 32487-32495. DOI
  6. Hu S.; Zhao P.; Nakano K.; Oliver R. D. J.; Pascual J.; Smith J. A.; Yamada T.; Truong M. A.; Murdey R.; Shioya N.; Hasegawa T.; Ehara M.; Johnstron M. B.; Tajima K.; Kanemitsu Y.; Snaith H. J.; Wakamiya A.; Synergistic Surface Modification of Tin–Lead Perovskite Solar Cells, Adv. Mater., 2023, 35, 2208320. DOI
  7. Wang W.-C.; Nakano K.; Tanaka Y.; Ishii H.; Hsu C.-S.; Tajima K.; Stabilization of Spontaneous Orientation Polarization by Preventing Charge Injection from Electrodes, J. Photopolym. Sci. Tech., 2023, 36, 161-166. DOI
  8. Suzuki R.; Ochiai Y.; Nakano K.; Miyasaka M.; Tajima K.; Detrimental Effects of “Universal” Singlet Photocrosslinkers in Organic Photovoltaics, ACS Appl. Energy Mater., 2023, 6, 4982-4988. DOI
  9. Wang W.-C.; Nakano K.; Hsu C.-S.; Tajima K.; Synthesis of 2,5,8-Tris(1-phenyl-1H-benzo[d]imidazol-2-yl)benzo[1,2-b:3,4-b′:5,6-b″] Trithiophenes and Their Spontaneous Orientation Polarization in Thin Films, ACS Appl. Mater. Interfaces, 2023, 15, 20294-20301. DOI


  1. Nakano K.; Kaji Y.; Tajima K.; Impact of Narrowing Density of States in Semiconducting Polymers on Performance of Organic Field-Effect Transistors, Small, 2022, 19, 2205570. DOI
  2. Chen F.; Nakano K.; Kaji Y.; Tajima K.; Design of Planar-Zigzag Semiconducting Polymers to Control Chain Orientation and Electronic Structure for Organic Photovoltaics, Mater. Chem. Front., 2022, 6, 3062-3069. DOI
  3. Wang W.-C.; Nakano K.; Hashizume D.; Hsu C.-S.; Tajima K.; Tuning Molecular Conformations to Enhance Spontaneous Orientation Polarization in Organic Thin Films, ACS Appl. Mater. Interfaces, 2022, 14, 18773-18781. DOI
  4. Hu S.; Otsuka K.; Murdey R.; Nakamura T.; Truong M. A.; Yamama T.; Handa T.; Matsuda K.; Nakano K.; Sato A.; Marumoto K.; Tajima K.; Kanemitsu Y.; Wakamiya A.; Optimized Carrier Extraction at Interfaces for 23.6% Efficient Tin–Lead Perovskite Solar Cells, Energy Envron. Sci., 2022, 15, 2096-2107. DOI
  5. Wang C.; Hao H.; Tajima K.; Essential Role of Triplet Diradical Character for Large Magnetoresistance in Quinoidal Organic Semiconductor with High Electron Mobility, Adv. Sci., 2022, 9, 2201045. DOI
  6. Nakano K.; Chen F.; Kaji Y.; Tajima K.; ; Control of molecular orientations by sequential deposition to enhance organic photovoltaic performance, Mater. Chem. Phys., 2022, 281, 125849. DOI
  7. Xiong S.; Fukuda K.; Lee S.; Nakano K.; Dong X.; Yokota T.; Tajima K.; Zhou Y.; Someya T.; Ultrathin and Efficient Organic Photovoltaics with Enhanced Air Stability by Suppression of Zinc Element Diffusion, Adv. Sci., 2022, 9, 2105288. DOI


  1. Nakano K.; Terado K.; Kaji Y.; Yoshida H.; Tajima K.; Reduction of Electric Current Loss by Aggregation-Induced Molecular Alignment of a Non-Fullerene Acceptor in Organic Photovoltaics, ACS Appl. Mater. Interfaces, 2021, 1360299-60305. DOI
  2. Chen F.; Nakano K.; Kaji Y.; Adachi K.; Hashizume D.; Tajima K.; Triphenyleno[1,2-c:7,8-c′]bis([1,2,5]thiadiazole) as a V-Shaped Electron-Deficient Unit to Construct Wide-Bandgap Amorphous Polymers for Efficient Organic Solar Cells, ACS Appl. Mater. Interfaces, 2021, 13, 57743-57749. DOI
  3. Maeda A.; Liu R.; Yu. K.; Lee S.; Nakano K.; Takakuwa M.; Zhang S.; Tajima K.; Fukuda K.; Umezu S.; Someya T.; Photoactive layer formation in the dark for high performance of air-processable organic photovoltaics, J. Phys. Mater., 2021, 4, 044016. DOI
  4. Seo G.; Saito Y.; Nakamichi M.; Nakano K.; Tajima K.; Kanai K.; Mechanism of charge accumulation of poly(heptazine imide) gel, Sci. Rep., 2021, 11, 17833. DOI
  5. Nakano K.; Kaji Y.; Tajima K.; Highly Sensitive Evaluation of Density of States in Molecular Semiconductors by Photoelectron Yield Spectroscopy in Air, ACS Appl. Mater. Interfaces, 2021, 13, 28574-28582. DOI
  6. Wang F.; Nakano K.; Segawa H.; Tajima K.; Inversion of Circular Dichroism Signals in Chiral Polythiophene Films Induced by End-On-Oriented Surface-Segregated Monolayers, ACS Appl. Mater. Interfaces, 2021, 13, 7510-7516. DOI


  1. Nakano K.; Sanematsu H.; Kaji Y.; Takai A.; Tajima K.; Immobilization of Ethynyl-π-extended Electron Acceptors with Amino-terminated SAMs by Catalyst-free Click Reaction, Chem. Eur. J., 2020, 26, 15931-15937. DOI
  2. Sogawa H.; Nakano K.; Tateishi A.; Tajima K.; Numata K.; Surface Analysis of Native Spider Draglines by FE-SEM and XPS, Front. Bioeng. Biotechnol., 2020, 8, 231. DOI
  3. Wang C.; Hao H.; Hashizume D.; Tajima K.; Surface-induced Enantiomorphic Crystallization of Achiral Fullerene Derivatives in Thin Films, Chem. Sci., 2020, 11, 4702-4708. DOI
  4. Jiang Z.; Wang F.; Fukuda K.; Karki A.; Huang W.; Yu K.; Yokota T.; Tajima K.; Nguyen T.-Q.; Someya T.; Highly Efficient Organic Photovoltaics with Enhanced Stability through the Formation of Doping-induced Stable Interfaces, PNAS, 2020, 117, 6391-6397. DOI
  5. Wang W.-C.; Chen S.-Y.; Yang Y.-W.; Hsu C. S.; Tajima K.; Face-on Reorientation of π-Conjugated Polymers in Thin Films by Surface-Segregated Monolayers, J. Mater. Chem. A, 2020, 4, 2070013. DOI
  6. Takakuwa M.; Heo S. W.; Fukuda K.; Tajima K.; Park S.; Umezu S.; Someya T.; Nanograting Structured Ultrathin Substrate for Ultraflexible Organic Photovoltaics , Small methods, 2020, 4, 1900762. DOI
  7. Zhang C.; Nakano K.; Nakamura M.; Araoka F.; Tajima K.; Miyajima D.; Noncentrosymmetric Columnar Liquid Crystals with the Bulk Photovoltaic Effect for Organic Photodetectors , J. Am. Chem. Soc., 2020, 142, 3326. DOI


  1. Nakano K.; Chen Y.; Tajima K.; Quantifying Charge Carrier Density in Organic Solar Cells by Differential Charging Techniques, AIP Adv., 2019, 9, 125205. DOI
  2. Tajima K.; Look beyond the surface: recent progress in applications of surface-segregated monolayers for organic electronics, Polym. J., 2019, 51, 1117-1126. DOI
  3. Nakano M.; Nakano K.; Takimiya K.; Tajima K.; Two Isomeric Perylenothiophene Diimides: Physicochemical Properties and Applications in Organic Semiconducting Devices, J. Mater. Chem. C, 2019, 7, 2267-2275. DOI
  4. Li C.-H.; Chang C.-H.; Hsiao Y.-H.; Peng S.-H.; Su Y.-J.; Heo S.W.; Tajima K.; Tsai M.-C.; Lin C.-Y.; Hsu C.-S.; Porphyrin-Containing Polymer as a Superior Blue Light-Absorbing Additive To Afford High-Jsc Ternary Solar Cells, ACS Appl. Mater. Interfaces, 2019, 11, 1156-1162. DOI
  5. Nakano K.; Chen Y.; Xiao B.; Han W.; Huang J.; Yoshida H.; Zhou E.J.; Tajima K.; Anatomy of the energetic driving force for charge generation in organic solar cells, Nature Commun., 2019, 10, 2520. DOI
  6. Wang F.; Nakano K.; Segawa H.; Tajima K.; Phytol-derived Alkyl Side-chains for π-Conjugated Semiconducting Polymers, Chem. Mater., 2019, 31, 2097-2105. DOI
  7. Geng Y.F.; Tang A.L.; Tajima K.; Zeng Q.D.; Zhoug E.J.; Conjugated materials containing dithieno[3,2-b:2',3'-d]pyrrole and its derivatives for organic and hybrid solar cell applications, J. Mater. Chem. A, 2019, 7, 64-96. DOI


  1. Akaike K.; Kumai T.; Nakano K.; Abdullah S.; Ouchi S.; Uemura Y.; Ito Y.; Onishi A.; Yoshida H.; Tajima K.; Kanai K.; Effects of Molecular Orientation of a Fullerene Derivative at the Donor/Acceptor Interface on the Device Performance of Organic Photovoltaics, Chem. Mater., 2018, 30, 8233-8243. DOI
  2. Wang F.; Nakano K.; Yoshida H.; Hashimoto K.; Segawa H.; Hsu C.-S.; Tajima K.; Effects of End-On Oriented Polymer Chains at the Donor/Acceptor Interface in Organic Solar Cells, J. Mater. Chem. A, 2018, 6, 22880-22898. DOI
  3. Park S.; Heo S.W.; Lee W.; Inoue D.; Jiang Z.; Yu K.; Jinno H.; Hashizume D.; Sekino M.; Yokota T.; Fukuda K.; Tajima K.; Someya T.; Self-powered ultra-flexible electronics via nanograting-patterned organic photovoltaics, Nature, 2018, 561, 516-521. DOI
  4. Wang F.; Hashimoto K.; Segawa H.; Tajima K.; Synthesis of Poly(3-butylthiophene) with Trisiloxane End Group and Its Surface Segregation Behavior in Thin Films, J. Photopolym. Sci. Tech., 2018, 31, 151-156. DOI
  5. Wang C.; Nakano K.; Lee H. F.; Chen Y.; Hong Y.-L.; Nishiyama Y.; Tajima K.; Intermolecular Arrangement of Fullerene Acceptors around Semiconducting Polymers in Mixed Bulk Heterojunctions, Angew. Chem. Int. Ed., 2018, 57, 7034-7039. DOI RIKEN Research
  6. Wang F.; Hashimoto K.; Segawa H.; Tajima K.; Effects of Chain Orientation in Self-Organized Buffer Layers Based on Poly(3-alkylthiophene)s for Organic Photovoltaics, ACS Appl. Mater. Interfaces, 2018, 10, 8901-8908. DOI
  7. Ohnishi I.; Hashimoto K.; Tajima K.; Synthesis of Diketopyrrolopyrrole-based Polymers with Polydimethylsiloxane Side Chains And Their Application in Organic Field-effect Transistors, R. Soc. open sci., 2018, 5, 172025. DOI
  8. Izawa S.; Nakano K.; Suzuki K.; Chen Y.J.; Kikitsu T.; Hashizume D.; Koganezawa T.; Nguyen T.-Q. and Tajima K.; Crystallization and Polymorphism of Organic Semiconductor in Thin Film Induced by Surface Segregated Monolayers, Sci. Rep., 2018, 8, 481. DOI
  9. Nakano K.; Shibamori T; Tajima K.; Quantitative Evaluation of Molecular Diffusion in Organic Planar Heterojunctions by Time-of-Flight Secondary Ion Mass Spectroscopy, ACS Omega, 2018, 3, 1522-1528. DOI
  10. Yang J.; Chen F.; Xiao B.; Sun S.; Sun X.; Tajima K.; Tang A.; Zhou E.; Modulating the Symmetry of Benzodithiophene by Molecular Tailoring for the Application in Naphthalene Diimide Based n-type Photovoltaic Polymers, Solar RRL, 2018, 2, 1700230. DOI
  11. Tang A.L.; Xiao B.; Wang Y.M.; Gao F.; Tajima K.; Bin H.J.; Zhang Z.-G.; Li Y.F.; Wei Z.X.; Zhou E.J.; Simultaneously Achieved High Open-Circuit Voltage and Efficient Charge Generation by Fine-Tuning Charge-Transfer Driving Force in Nonfullerene Polymer Solar Cells, Adv. Funct. Mater., 2018, 28, 1704507. DOI


  1. Yang J.; Xiao B.; Heo S. W.; Tajima K.; Chen F.; Zhou E.J.; Effects of Inserting Thiophene as a π-Bridge on the Properties of Naphthalene Diimide-alt-Fused Thiophene Copolymers, ACS Appl. Mater. Interfaces2017, 9, 44070-44078. DOI
  2. Hamonnet J.; Nakano M.; Nakano K.;Sugino H.; Takimiya K.; Tajima K.; Bis(naphthothiophene diimide)indacenodithiophenes as Acceptors for Organic Photovoltaics, Chem. Mater.2017, 29, 9618-9622. DOI
  3. Hsiao Y.-T.; Li C.-H.; Chang S.-L.; Heo S.W.; Tajima K.; Cheng Y.-J.; Hsu C.-S.; Haptacyclic Carbazole-Based Ladder-Type Nonfullerene Acceptor with Side-Chain Optimization for Efficient Organic Photovoltaics, ACS App. Mater. Interfaces2017, 9, 42035-42042. DOI
  4. Suzuki K.; Izawa S.; Chan Y.J.; Nakano K.; Tajima K; Drawing Organic Photovoltaics Using Paint Marker Pens, AIP Advances2017, 7, 115002. DOI
  5. Tantitarntong P.; Zalar P.; Matsuhisa N.; Nakano K.; Lee S.; Yokota T.; Tajima K.; Someya T.; High Sensitivity Tuning of Work Function of Self-Assembled Monolayers Modified Electrodes Using Vacuum Ultraviolet Treatment, ACS Appl. Mater. Interfaces2017, 9, 28151-28156. DOI
  6. Ding G.D.; Tang A.L.; Chen F.; Tajima K.; Xiao B.; Zhou E.J.; Inside-fused Perylenediimide Dimers with Planar Structures for High-performance Fullerene-free Organic Solar Cells, RSC Adv.2017, 7, 13749-13753. DOI
  7. Heo S.W.; Le H.H.T.; Tanaka T.; Osaka I.; Takimiya K.; Tajima K.; Cumulative Gain in Organic Solar Cells by Using Multiple Optical Nanopatterns, J. Mater. Chem. A2017, 5, 10347-10354. DOI
  8. Huang J.; Nakano K.; Suzuki K.; Chen Y.J.; Wang F.J.; Koganezawa T.; Tajima K.; π-Conjugation Effects of Oligo(thienylenevinylene) Side Chains in Semiconducting Polymers on Photovoltaic Performance, Macromolecules2017, 50, 3557-3564. DOI
  9. Yang J.; Xiao B., Tajima K.; Nakano M.; Takimiya K.; Tang A.; Zhou E.; Comparison among Perylene Diimide (PDI), Naphthalene Diimide (NDI), and Naphthodithiophene Diimide (NDTI) Based n-Type Polymers for All-Polymer Solar Cells Application, Macromolecules2017, 50, 3179-3185. DOI
  10. Chen P.H.; Nakano K.; Suzuki K.; Hashimoto K.; Kikitsu T.; Hashizume D.; Koganezawa T.; Tajima K.; Organic Solar Cells with Controlled Nanostructures Based on Microphase Separation of Fullerene-attached Thiophene-Selenophene Heteroblock Copolymers, ACS Appl. Mater. Interfaces2017, 9, 4758-4768. DOI
  11. Li Z.; He P.; Chong H.; Furube A.; Seki K.; Yu H.-H.; Tajima K.; Ito Y.; Kawamoto M.; Direct Aqueous Dispersion of Carbon Nanotubes Using Nanoparticle-Formed Fullerenes and Self-Assembled Formation of p/n Heterojunctions with Polythiophene, ACS Omega, 2017, 2, 1625-1632. DOI
  12. Nakano K.; Tajima K.; Organic Planar Heterojunctions: From Models for Interfaces in Bulk Heterojunctions to High-Performance Solar Cells, Adv. Mater.2017, 29, 1603269. DOI


  1. Nakano K.; Chen Y.J.; Suzuki K.; Tajima K.; Modification of Donor/Acceptor Interface for Efficient Organic Photovoltaics, J. Photopolym. Sci. Tech.2016, 29, 533-536. DOI
  2. Nakano K.; Suzuki K.; Chen Y.J.; Tajima K.; Roles of Energy/Charge Cascades and Intermixed Layers at Donor/Acceptor Interfaces in Organic Solar Cells, Sci. Rep.2016, 6, 29529. DOI
  3. Nakano K.; Nakano M.; Xiao B.; Zhou E.J.; Suzuki K.; Osaka I.; Takimiya K.; Tajima K.; Naphthodithiophene Diimide-Based Copolymers: Ambipolar Semiconductors in Field-Effect Transistors and Electron Acceptors with Near-Infrared Response in Polymer Blend Solar Cells, Macromolecules2016, 49, 1752-1760. DOI
  4. Nikiforidis G.; Tajima K.; Byon H.-R.;  High Energy Efficiency and Stability for Photoassisted Aqueous Lithium-Iodine Redox Batteries, ACS Energy Lett.2016, 1, 806-813. DOI
  5. Zhong Y.F.; Suzuki K.; Inoue D.; Hashizume D.; Izawa S.; Hashimoto K.; Koganezawa T.; Tajima K.; Interface-induced Crystallization and Nanostructure Formation of [6,6]-Phenyl-C61-butyric Acid Methyl Ester (PCBM) in Polymer Blend Films and Its Application in Photovoltaics, J. Mater. Chem. A2016, 4, 3335-3341. DOI


  1. Geng Y.F.; Xiao B.; Izawa S.; Huang J.; Tajima K.; Zeng Q.; Zhou E.J.; Fullerene-free Organic Photovoltaics Based on Unconventional Material Combination: A Molecular Donor and Polymeric Acceptors, J. Mater. Chem. A2015, 44, 22325-22331. DOI
  2. Wang X.; Huang J.; Tajima K.; Zhou E.J.; An amorphous N-type polymer based on perylenediimide and selenophene for all-polymer solar cells application, Mater. Today Commun.2015, 4, 16-21. DOI
  3. Wang F.; Hashimoto K.; Tajima K.; Optical Anisotropy and Strong H-Aggregation of Poly(3-Alkylthiophene) in a Surface Monolayer, Adv. Mater.2015, 39, 6014-6020. DOI RIKEN Research
  4. Izawa S.; Nakano K.; Suzuki K.; Hashimoto K.; Tajima K.; Dominant Effects of First Monolayer Energetics at Donor/Acceptor Interfaces on Organic Photovoltaics, Adv. Mater.2015, 27, 3025-3031. DOI RIKEN Research
  5. Geng Y.F.; Huang J.M.; Tajima K.; Zeng Q.D.; Zhou E.J.; A Low Band Gap n-type Polymer Based on Dithienosilole and Naphthalene Diimide for All-polymer Solar Cells Application, Polymer2015, 63, 164-169. DOI
  6. Zhong Y.F.; Izawa S.; Hashimoto K.; Tajima K.; Koganezawa T.; Yoshida H.; Crystallization-Induced Energy Level Change of [6,6]-Phenyl-C61-Butyric Acid Methyl Ester (PCBM) Film: Impact of Electronic Polarization Energy, J. Phys. Chem. C2015, 119, 23-28. DOI


  1. Geng Y.F.; Cong J.Z.; Tajima K.; Zeng Q.D.; Zhou E.J.; Synthesis and Properties of D–A Copolymers Based on Dithienopyrrole and Benzothiadiazole with Various Numbers of Thienyl Units as Spacers, Polym. Chem.2014, 5, 6797-6803. DOI
  2. Izawa S.; Nishizawa T.; Hashimoto K.; Koganezawa T.; Tajima K.; Separated Crystallization of Donor and Acceptor in Oligo(p-phenylenevinylene)-Naphthalenediimide Dyad Films, Synth. Met.2014, 197, 175-181. DOI
  3. Wei Q.S.; Miyanishi S.; Zhou E.j.; Hashimoto K.; Tajima K.; Poly(4-hexyloxythiazole): A New Low Band Gap Semiconductor for Polymer Electronics, Synth. Met.2014, 196, 139-144. DOI
  4. Zhou E.J.; Nakano M.; Izawa S.; Cong J.Z.; Osaka I.; Takimiya K.; Tajima K.; All-Polymer Solar Cell with High Near-infrared Response Based on A Naphthodithiophene Diimide (NDTI) Copolymer, ACS Macro Lett.2014, 3, 872-875. DOI
  5. Izawa S.; Hashimoto K.; Tajima K.; Surface Functionalization of Organic Semiconductor Films by Segregated Monolayers, Phys. Chem. Chem. Phys.2014, 16, 16383-16387. DOI
  6. Martinez L.; Higuchi S.; Maclachlan A.; Stavrinadis A.; Miller N. C.; Diedenhofen S. L.; Bernechea M.; Sweetnam S.; Nelson J.; Haque S. A.; Tajima K.; Konstantatos G.; Improved Electronic Coupling in Hybrid Organic-inorganic Nanocomposites Employing Thiol-functionalized P3HT and Non-toxic Bismuth Sulfide Nanocrystals, Nanoscale2014, 6, 10018-10026. DOI
  7. Yamamoto S.; Yasuda H.; Ohkita H.; Benten H.; Ito S.; Miyanishi S.; Tajima K.; Hashimoto K.; Charge Generation and Recombination in Fullerene-Attached Poly(3-hexylthiophene)-Based Diblock Copolymer Films, J. Phys. Chem. C2014, 118, 10584-10589. DOI
  8. Ma J.S.; Hashimoto K.; Koganezawa T.; Tajima K.; Enhanced Vertical Carrier Mobility in Poly(3-alkylthiophene) Thin Films Sandwiched with Self-assembled Monolayer and Surface-segregated Layer, Chem. Commun.201450, 3627-3630. DOI
  9. Zhong Y.F.; Tada A.;  Izawa S.; Hashimoto K.; Tajima K.; Enhancement of VOC without Loss of JSC in Organic Solar Cells by Modification of Donor/Acceptor Interfaces, Adv. Energy Mater. 2014, 4, 1301332. DOI


  1. Zhou E.J.; Hashimoto K.; Tajima K.; Low Band Gap Polymers for Photovoltaic Device with Photocurrent Response Wavelengths over 1000 nm, polymer201354, 6501-6509. DOI
  2. Zhou E.J.; Cong, J.Z.;  Hashimoto K.; Tajima K.; Control of Miscibility and Aggregation via Material Design and Coating Process for High-Performance Polymer Blend Solar Cell, Adv. Mater. 201325, 6991–6996. DOI
  3. Geng Y.F.; Ma J.S.; Wei Q.S.; Hashimoto K.; Tajima K.; Effects of Side Chain Sequence on Surface Segregation of Regioregular Poly (3-alkylthiophene) and Interfacial Modification of Bilayer Organic Photovoltaic Devices, J. Mater. Chem. A 20131, 11867-11873. DOI
  4. Zhong Y.F.; Tada A.;  Geng Y.F.; Wei Q.S.; Hashimoto K.; Tajima K.; Donor/Acceptor Interface Modifications in Organic Solar Cells, J. Photopolym. Sci. Tech. 201326, 181-184. DOI
  5. Ma J.S.; Hashimoto K.; Koganezawa T.; Tajima K.; End-On Orientation of Semiconducting Polymers in Thin Films Induced by Surface Segregation of Fluoroalkyl Chains, J. Am. Chem. Soc. 2013135, 9644-9647. DOI
  6. Martinez L.; Stavrinadis A.; Higuchi S.; Diedenhofen S. L.; Bernechea M.; Tajima K.; Konstantatos G.; Hybrid Solution-processed Bulk Heterojunction Solar Cells Based on Bismuth Sulfide Nanocrystals, Phys. Chem. Chem. Phys. 201315, 5482-5487. DOI
  7. Zhao M.X.; Hashimoto K.; Tajima K.; Synthesis of Copolymer Based on Naphthalene Diimide Connected with a Non-conjugated Flexible Linker, Synth. Met. 2013, 175, 9-14. DOI
  8. Zhao M.X.; Hashimoto K.; Tajima K.; Organic Electronic Devices with Copolymers Based on Naphthalene Diimide Connected with Non Conjugated Flexible Linker, Jpn. J. Appl. Phys.201352, 05DA15. DOI
  9. Ma J.S.; Geng Y.F.; Hashimoto K.; Tajima K.; Synthesis and Characterization of End-Functionalized Poly(3-butylthiophene) with Semifluoroalkyl Chains, Macromol. Chem. Phys. 2013, 214, 1326–1331. DOI
  10. Zhou E.J.; Cong, J.Z.; Hashimoto K.; Tajima K.; A Benzoselenadiazole-Based Low Band Gap Polymer: Synthesis and Photovoltaic Application, Macromolecules201346, 763–768. DOI
  11. Zhong Y.F.; Ma J.S.; Hashimoto K.; Tajima K.; Electric Field-Induced Dipole Switching at the Donor/Acceptor Interface in Organic Solar Cells, Adv. Mater. 2013, 25, 1071-1075. DOI


  1. Zhou E.J.; Cong, J.Z.; Hashimoto K.; Tajima K.; Introduction of a Conjugated Side Chain as an Effective Approach to Improving Donor-Acceptor Photovoltaic Polymers, Energy Environ. Sci.20125, 9756-9759.  DOI
  2. Izawa S.; Hashimoto K.; Tajima K.; Synthesis, Characterization, and Photovoltaic Properties of Diketopyrrolopyrrole-oligothiophene/Fullerene Dyads, Synth. Met.2012162, 2201-2205. DOI
  3. Izawa S.; Hashimoto K.; Tajima K.; Morphological Stability of Organic Solar Cells Based upon Oligo(p-phenylenevinylene)-C70 Dyad,Phys. Chem. Chem. Phys.201214, 16138-16142. DOI
  4. Miyanishi S.; Zhang Y.; Hashimoto K.; Tajima K.; Controlled Synthesis of Fullerene-Attached Poly(3-alkylthiophene)-Based Copolymers for Rational Morphological Design in Polymer Photovoltaic Devices, Macromolecules201245, 6424−6437.  DOI
  5. Zhou E.J.; Cong J.Z.; Zhao M.X.; Zhang L.Z.; Hashimoto K.; Tajima K.; Synthesis and application of poly(fluorene-alt-naphthalene diimide) as an n-type polymer for all-polymer solar cells,  Chem. Commun.201248, 5283-5285.  DOI
  6. Tada A.; Geng Y.F.; Nakamura M.; Wei Q.-S.,Hashimoto K.; Tajima K.; Interfacial modification of organic photovoltaic devices by molecular self-organization. Phys. Chem. Chem. Phys.2012, 14, 3713 - 3724. DOI
  7. Zhang L.Z.; Hashimoto K.; Tajima K.; End-group stannylation of regioregular poly(3-hexylthiophene)s. Polymer J.201244, 1145–1148. DOI
  8. Zhang L.Z.; Zhang Y.; Wei Q.S.; Zhou E.J.; Yang C.H.; Hashimoto K.; Tajima K.; Effects of Block Length in Copolymers Based on Regioregular Oligothiophenes Linked with Electron-Accepting Units. Macromol. Rapid Commun.2012,  33, 658-663. DOI
  9. Zhou E.J.; Cong J.Z.; Tajima K., Yang C.H.; Hashimoto K.; Conjugated Polymers Based on 1,3-Dithien-2-yl-thieno[3,4-c]pyrrole-4,6-dione: Synthesis, Characterization,and Solvent Effects on Photovoltaic Performance. J. Phys. Chem. C2012116, 2608–2614. DOI


  1. Yang C.H.; Zhou E.J.; Miyanishi S.; Hashimoto K.;Tajima K.; Preparation of Active Layers in Polymer Solar Cells by Aerosol Jet Printing. ACS Appl. Mater. Interface, 20113, 4053–4058. DOI
  2. Geng Y.F.; Hashimoto K.; Tajima K.; Synthesis of Regioregular Poly(3-alkylthiophene) with Alternating Dodecyl/1H,1H,2H,2H-Perfluorooctyl Side Chains. Macromol. Rapid Commun.201132, 1478–1483. DOI
  3. Zhang L.Z.; Tajima K.; Hashioto K.; Low Bandgap Polymers Based on Regioregular Oligothiophenes Linked with Electron-Accepting Units. Macromolecules201144, 4222–4229. DOI
  4. Izawa S.; Tajima K.; Hashimoto K.; Efficient Charge Generation and Collection in Organic Solar Cells Based on Low Band Gap Dyad Molecules. Chem. Commun.201147, 6365-6367. DOI
  5. Sato S.; Tajima K.; Hashimoto K.; Synthesis and Photovoltaic Application of Donor-acceptor Type Copolymers Containing 9-Cyanomethylenefluorene Derivatives with Chemically Tunable Electronic Properties. Synth. Met. 2011161, 1289-1298. DOI (Cover Picture)
  6. Geng Y.F.; Hashimoto K.; Tajima K.; Dipole Layer Formation by Surface Segregated Monolayer of Poly(3-alkylthiophene) with Alternating Semifluoroalkyl Side Chains. Chem. Mater., 201123, 4257–4263. DOI
  7. Tada A.; Geng Y.F.; Wei Q.S.; Hashimoto K.; Tajima K.; Tailoring organic heterojunction interfaces in bilayer polymer photovoltaic devices. Nature Mater.201110, 450–455. DOI
  8. Wei Q.S.; Hashimoto K.; Tajima K.; Experimental Investigation of Charge Carrier Transport in Organic Thin-film Transistors with "Buried Surface Layers". ACS Appl. Mater. Interfaces2011, 3, 139–142. DOI
  9. Zhang Y.; Tajima K.; Hashimoto K.; Field-effect Hole Mobility of Poly(3-hexylthiophene-block-3-(2-ethylhexyl)thiophene)s. Synth. Met.,2011, 161, 225-228 (Cover Picture). DOI.
  10. Zhou E.J.; Cong J.Z.; Wei Q.S.; Tajima K.; Yang C.H.; Hashimoto K.; All-Polymer Solar Cells Based on Perylene Diimide–Based Copolymers: Material Design and Phase Separation Control, Angew. Chem. Int. Ed.2011, 50, 2799-2803. DOI
  11. Zhou E.J.; Cong J.Z.; Tajima K.; Yang C.H.; Hashimoto K.; Synthesis and Photovoltaic Properties of Donor-Acceptor Copolymer based on Dithienopyrrole and Thienopyrroledione. Macromol. Chem. Phys.2011, 212, 305-310. DOI
  12. Tajima K.; Hashimoto K.; Nanostructure Control in Polymer Solar Cells by Self-Organization. Chem. Rec.2011, 11, 8-17. DOI
  13. Yan X.; Li B.S.; Cui X.;Wei Q.S.; Tajima K.; Li L.S.; Independent Tuning of the Band Gap and Redox Potential of Graphene Quantum Dots. J. Phys. Chem. Lett.2011, 2, 1119-1124. DOI


  1. Zhou, E.J.; Cong, J.Z.; Tajima K.; Hashimoto K.; Synthesis and Photovoltaic Properties of Donor-Acceptor Copolymers Based on 5,8-Dithien-2-yl-2,3-diphenylquinoxaline. Chem. Mater., 2010, 22, 4890–4895. DOI
  2. Miyanishi S.; Zhang Y.; Tajima K.; Hashimoto K.; Fullerene Attached All-Semiconducting Diblock Copolymers for Stable Single Component Polymer Solar Cells. Chem. Commun.2010, 46, 6723-6725. DOI
  3. Wei Q. S.; Tajima, K.; Hashimoto, K., Electrical Instability of Polymer Thin-Film Transistors Using Contact Film Transfer Methods. Appl. Phys. Lett.2010, 96, 243301. DOI
  4. Zhou, E. J.; Cong, J.Z.; Yamakawa. S.; Wei Q.S.; Nakamura. M.; Tajima, K; Yang, C. H.; Hashimoto, K., Synthesis of Thieno[3,4-b]pyrazine-Based and 2,1,3-Benzothiadiazole-Based Donor−Acceptor Copolymers and their Application in Photovoltaic Devices. Macromolecules2010, 43, 2873-2879. DOI
  5. Zhou, E. J.;Tajima, K; Yang, C. H.; Hashimoto, K., Band gap and molecular energy level control of perylene diimide-based donor–acceptor copolymers for all-polymer solar cells.  J. Mater. Chem., 2010, 12, 2362-2368. DOI
  6. Zhou, E. J.; Wei, Q. S.; Yamakawa, S; Zhang, Y; Tajima, K; Yang, C. H.; Hashimoto, K., Diketopyrrolopyrrole-based Semiconducting Polymers for Photovoltaic Device with Photocurrent Response Wavelengths up to 1.1 μm. Macromolecules2010, 43, 821-826. DOI


  1. Nakamura, M.; Yang, C. H.; Zhou, E. J.; Tajima, K.; Hashimoto, K.,  Polymer Bulk Heterojunction Photovoltaic Devices with Multilayer Structures Prepared by Thermal Lamination. ACS Appl. Mater. Interfaces2009, 1, 2703. DOI
  2. Wei, Q. S.; Miyanishi, S.; Tajima, K.; Hashimoto, K., Enhanced Charge Transport in Polymer Thin-Film Transistors Prepared by Contact Film Transfer Method. ACS Appl. Mater. Interfaces2009, 1, 2660. DOI
  3. Wei, Q. S.; Tajima, K.; Tong, Y. J.; Ye, S.; Hashimoto, K.,  Surface-Segregated Monolayers: A New Type of Ordered Monolayer for Surface Modification of Organic Semiconductors. J. Am. Chem. Soc.2009, 131, 19597. DOI
  4. Zhou, E. J.; Yamakawa, S.; Zhang, Y.; Tajima, K.; Yang, C. H.; Hashimoto, K., Indolo[3,2-b]carbazole-based Alternating Donor-acceptor Copolymers: Synthesis, Properties and Photovoltaic Application. J. Mater. Chem. 2009, 19, 7730. DOI
  5. Zhou, E. J.; Yamakawa, S. P.; Tajima, K.; Yang, C. H.; Hashimoto, K., Synthesis and Photovoltaic Properties of Diketopyrrolopyrrole-Based Donor-Acceptor Copolymers. Chem. Mater. 2009, 21, 4055. DOI
  6. Wei, Q. S.; Tajima, K.; Hashimoto, K., Bilayer Ambipolar Organic Thin-Film Transistors and Inverters Prepared by the Contact-Film-Transfer Method. ACS Appl. Mater. Interfaces 2009, 1, 1865. DOI
  7. Zhang, Y.; Tajima, K.; Hashimoto, K., Nanostructure Formation in Poly(3-hexylthiophene-block3-(2-ethylhexyl)thiophene)s. Macromolecules 2009, 42, 7008. DOI
  8. Nakamura, M.; Yang, C. H.; Tajima, K.; Hashimoto, K., High-performance Polymer Photovoltaic Devices with Inverted Structure Prepared by Thermal Lamination. Sol. Energy Mater. Sol. Cells 2009, 93, 1681. DOI
  9. Nishizawa, T.; Lim, H. K.; Tajima, K.; Hashimoto, K., Efficient Dyad-based Organic Solar Cells with a Highly Crystalline Donor Group. Chem. Commun. 2009, 2469. DOI
  10. Yamakawa, S.; Tajima, K.; Hashimoto, K., Buffer Layer Formation in Organic Photovoltaic Cells by Self-organization of Poly(dimethylsiloxane)s. Org. Electron. 2009, 10, 511. DOI
  11. Miyanishi, S.; Tajima, K.; Hashimoto, K., Morphological Stabilization of Polymer Photovoltaic Cells by Using Cross-Linkable Poly(3-(5-hexenyl)thiophene). Macromolecules 2009, 42, 1610. DOI
  12. Sato, S.; Tajima, K.; Hashimoto, K., Synthesis and Characterization of Regioregular Cyano-Substituted Poly(p-phenylenevinylene).Macromolecules 2009, 42, 1785. DOI
  13. Nishizawa, T.; Lim, H. K.; Tajima, K.; Hashimoto, K., Highly Uniaxial Orientation in Oligo(p-phenylenevinylene) Films Induced During Wet-Coating Process. J. Am. Chem. Soc. 2009, 131, 2464. DOI


  1. Zhou, E. J.; Nakamura, M.; Nishizawa, T.; Zhang, Y.; Wei, Q. S.; Tajima, K.; Yang, C. H.; Hashimoto, K., Synthesis and Photovoltaic Properties of a Novel Low Band Gap Polymer Based on N-Substituted Dithieno[3,2-b:2 ',3 '-d]pyrrole. Macromolecules 2008, 41, 8302.  DOI
  2. Takanezawa, K.; Tajima, K.; Hashimoto, K., Charge Separation Interfaces in Polymer Photovoltaic Devices Hybridized with ZnO Nanorod Arrays. Jpn. J. Appl. Phys. 2008, 47, 8049. DOI 
  3. Nishizawa, T.; Tajima, K.; Hashimoto, K., The Effect of Crystallinity in Donor Groups on the Performance of Photovoltaic Devices Based on an Oligothiophene-fullerene Dyad. Nanotechnology 2008, 19, 424017. DOI
  4. Takanezawa, K.; Tajima, K.; Hashimoto, K., Efficiency Enhancement of Polymer Photovoltaic Devices Hybridized with ZnO Nanorod Arrays by the Introduction of a Vanadium Oxide Buffer Layer. Appl. Phys. Lett. 2008, 93, 063308. DOI 
  5. Wei, Q. S.; Nishizawa, T.; Tajima, K.; Hashimoto, K., Self-organized Buffer Layers in Organic Solar Cells. Adv. Mater. 2008, 20, 2211. DOI
  6. Tajima, K.; Suzuki, Y.; Hashimoto, K., Polymer Photovoltaic Devices Using Fully Regioregular Poly[(2-methoxy-5-(3 ',7 '-dimethyloctyloxy))-1,4-phenylenevinylene]. J. Phys. Chem. C 2008, 112, 8507. DOI
  7. Zhang, Y.; Tajima, K.; Hirota, K.; Hashimoto, K., Synthesis of All-conjugated Diblock Copolymers by Quasi-living Polymerization and Observation of Their Microphase Separation. J. Am. Chem. Soc. 2008, 130, 7812. DOI


  1. Suzuki, Y.; Hashimoto, K.; Tajima, K., Synthesis of Regioregular Poly(p-henylenevinylene)s by Horner Reaction and Their Regioregularity Characterization. Macromolecules 2007, 40, 6521. DOI
  2. Nishizawa, T.; Tajima, K.; Hashimoto, K., Supramolecular Formation of Fibrous Nanostructure in Donor-acceptor Dyad. J. Mater. Chem. 2007, 17, 2440. DOI
  3. Takanezawa, K.; Hirota, K.; Wei, Q. S.; Tajima, K.; Hashimoto, K., Efficient Charge Collection with ZnO Nanorod Array in Hybrid Photovoltaic Devices. J.Phys. Chem. C 2007, 111, 7218. DOI
  4. Hirota, K.; Tajima, K.; Hashimoto, K., Physicochemical Study of Discotic Liquid Crystal Decacyclene Derivative and Utilization in Polymer Photovoltaic Devices. Synth. Met. 2007, 157, 290. DOI


  1. Wei, Q. S.; Hirota, K.; Tajima, K.; Hashimoto, K., Design and Synthesis of TiO2 Nanorod Assemblies and Their Application for Photovoltaic Devices. Chem. Mater. 2006, 18, 5080. DOI
  2. Kida, K.; Hirota, K.; Tajima, K.; Hashimoto, K., Photocatalytic Printing of Nanostructures on TiO2 Using Diblock Copolymer. Chem. Mater. 2006, 18, 1386. DOI


  1. Hirota, K.; Tajima, K.; Hashimoto, K., Facile Preparation of Nanoelectrode Ensembles Using Amphiphilic Block Copolymer Film. Langmuir 2005, 21, 11592. DOI