Associate Professor


Department of Chemistry, Faculty of Science

Hokkaido University

Kita 10, Nishi 8, Kita-ku, Sapporo, Hokkaido

060-0810 Japan

E–mail: junharada[at]sci.hokudai.ac.jp


1992: B.S., Faculty of Science, The University of Tokyo

1994: M.S., Graduate School of Science, The University of Tokyo

1997: Ph.D., Graduate School of Science, The University of Tokyo

Professional Positions

1997–1999: Postdoctoral fellow at Tokyo Institute of Technology (Prof. Yuji Ohashi)

1999–2012: Assistant professor at Graduate School of Arts and Sciences, The University of Tokyo (Prof. Keiichiro Ogawa)

2012–present: Associate professor at Faculty of Science, Hokkaido University.

Research Keywords

Molecular motions in crystals; Ferroelectric molecular crystals; Plastic crystals; X-ray Crystallography; Photochromism and thermochromism; Tautomerization



J. Harada, M. Takehisa, Y. Kawamura, H. Takahashi, and Y. Takahashi “Plastic/Ferroelectric Crystals with Distorted Molecular Arrangement: Ferroelectricity in Bulk Polycrystalline Films through Lattice ReorientationAdv. Electron. Mater., in press.



S. Yokokura, A. Tomimatsu, J. Ishiguro, J. Harada, H. Takahashi, Y. Takahashi, Y. Nakamura, H. Kishida, R. Suizu, M. M. Matsushita, and K. Awaga “Stabilization of Interfacial Polarization and Induction of Polarization Hysteresis in Organic MISIM DevicesACS Appl. Mater. Interfaces, 13, 31928–31933 (2021).

Y. Takahashi, K. Ishida, S. Matsuno, M. Kurokawa, T. Shimada, J. Harada, and T. Inabe “Charge injection phenomena at the contact interface between 5,10,15,20-tetra(methyl)porphyrin cobalt and 2,5-difluoro-7,7,8,8-tetracyanoquinodimethane single crystalsCrystEngComm, 23, 3975–3980 (2021).

J. Harada “Plastic/ferroelectric molecular crystals: Ferroelectric performance in bulk polycrystalline formsAPL Mater., 9, 020901 (2021).


Y. Takahashi, T. Kondo, S. Yokokura, M. Takehisa, J. Harada, T. Inabe, M. M. Matsushita, and K. Awaga “Electric and Thermosalient Properties of a Charge-Transfer Complex Exhibiting a Minor Valence Instability TransitionCryst. Growth Des., 20, 4758–4763 (2020).

Y. Takahashi, M. Takehisa, E. Tanaka, J. Harada, R. Kumai, and T. Inabe “Incorporating Spacer Molecules into the Tetrathiafulvalene-p-Chloranil Charge-Transfer Framework: Modulating the Neutral–Ionic Phase TransitionJ. Phys. Chem. Lett., 11, 1336–1342 (2020).

M. Yoneya and J. Harada “Molecular Dynamics Simulation Study of the Plastic/Ferroelectric Crystal Quinuclidinium Perrhenate

J. Phys. Chem. C, 124, 2171–2177 (2020).


J. Harada, Y. Kawamura, Y. Takahashi, Y. Uemura, T. Hasegawa, H. Taniguchi, and K. Maruyama “Plastic/Ferroelectric Crystals with Easily Switchable Polarization: Low-Voltage Operation, Unprecedentedly High Pyroelectric Performance, and Large Piezoelectric Effect in Polycrystalline FormsJ. Am. Chem. Soc., 141, 9349-9357 (2019).

J. Harada, N. Yoneyama, S. Sato, Y. Takahashi, and T. Inabe “Crystals of Charge-Transfer Complexes with Reorienting Polar Molecules: Dielectric Properties and Order–Disorder Phase TransitionsCryst. Growth Des., 19, 291-299 (2019).


K. Kobayashi, H. Hasegawa, Y. Takahashi, J. Harada, and T. Inabe “Electronic Properties of Tin Iodide Hybrid Perovskites: Effect of Indium DopingMater. Chem. Front., 2, 1291–1295 (2018).

T. Shimada, Y. Takahashi, J. Harada, H. Hasegawa, and T. Inabe “Band-Like Carrier Transport at the Single-Crystal Contact Interfaces Between 2,5-Difluoro-7,7,8,8-Tetracyanoquinodimethane and Electron DonorsJ. Phys. Chem. Lett., 9, 420-424 (2018).

J. Harada, N. Yoneyama, S. Yokokura, Y. Takahashi, A. Miura, N. Kitamura, and T. Inabe “Ferroelectricity and Piezoelectricity in Free-Standing Polycrystalline Films of Plastic CrystalsJ. Am. Chem. Soc., 140, 346-354 (2018).


J. Harada, M. Taira, and K. Ogawa “Photochromism of Fulgide Crystals: From Lattice-Controlled Product Accumulation to Phase SeparationCryst. Growth Des.,17, 2682–2687 (2017).

H. Hasegawa, K. Kobayashi, Y. Takahashi, J. Harada, and T. Inabe “Effective band gap tuning by foreign metal doping in hybrid tin iodide perovskitesJ. Mater. Chem. C, 5, 4048–4052 (2017).

M. Kurokawa, J. F. F. Jose-Larong, H. Hasegawa, Y. Takahashi, J. Harada, and T. Inabe “Structural and transport properties of neutral radical crystals of CoIII(tmp)(CN)2 (tmp = 5,10,15,20-tetramethylporphyrinato) and the CN-bridged polymer [CoIII(tmp)(CN)]nDalton Trans., 46, 4422–4429 (2017).


Y. Takahashi, T. Mikasa, K. Hayakawa, S. Yokokura, H. Hasegawa, J. Harada and T. Inabe “Fabrication of Conducting Thin Films on the Surfaces of 7,7,8,8-Tetracyanoquinodimethane Single-Component and Charge-Transfer Complex Single Crystals: Nucleation, Crystal Growth, Morphology, and Charge TransportJ. Phys. Chem. C, 120, 17537-17545 (2016).

J. Harada, T. Shimojo, H. Oyamaguchi, H. Hasegawa, Y. Takahashi, K. Satomi, Y. Suzuki, J. Kawamata, and T. Inabe “Directionally tunable and mechanically deformable ferroelectric crystals from rotating polar globular ionic moleculesNature Chem., 8, 946-952 (2016).


H. Kubota, Y. Takahashi, H. Hasegawa, T. Shimada, Jun Harada, and T. Inabe “Charge Carrier Doping into the Peierls Insulator of the TCNQ Anion Radical Salt (TCNQ = 7,7,8,8-Tetracyanoquinodimethane)J. Phys. Chem. C, 120, 11545–11551 (2016).


S. Yokokura, Y. Takahashi, H. Nonaka, H. Hasegawa, J. Harada, T. Inabe, R. Kumai, H. Okamoto, M. M. Matsushita, and K. Awaga “Switching of Transfer Characteristics of an Organic Field-Effect Transistor by Phase Transitions: Sensitive Response to Molecular Dynamics and Charge FluctuationChem. Mater., 27, 4441–4449 (2015).

J. Harada, M. Ohtani, Y. Takahashi, and T. Inabe “Molecular Motion, Dielectric Response, and Phase Transition of Charge-Transfer Crystals: Acquired Dynamic and Dielectric Properties of Polar Molecules in CrystalsJ. Am. Chem. Soc., 137, 4477–4486 (2015).

T. Mikasa, Y. Takahashi, K. Hayakawa, S. Yokokura, H. Hasegawa, J. Harada, and T. Inabe “Highly ordered alignment of conducting nano-crystallites on organic semiconductor single crystal surfacesThin Solid Films, 579, 38–43 (2015).


H. Kubota, Y. Takahashi, J. Harada, and T. Inabe “Structural and Physical Properties of a Series of 7,7,8,8-Tetracyanoquinodimethane Salts with Dications Bearing Two Terminal Pyridinium RingsCryst. Groth Des., 14, 5575–5584 (2014).

Y. Takita, H. Hasegawa, Y. Takahashi, J. Harada, A. Kanda, N. Hanasaki, and T. Inabe “One-dimensional phthalocyanine-based conductor with S = 3/2 isotropic magnetic centers” J. Porphyrins Phthalocyanines, 18, 814–823 (2014).

J. Harada, and K. Ogawa “What Molecules Are Likely or Unlikely To Undergo Pedal Motions in Crystals?Cryst. Groth Des., 14, 5182–5188 (2014).

G. S. Lorena, H. Hasegawa, Y. Takahashi, J. Harada, and T. Inabe “Hole Doping of Tin Bromide and Lead Bromide Organic-Inorganic Hybrid SemiconductorsChem. Lett., 43, 1535–1537 (2014).

H. Kamebuchi, M. Okubo, A. Okazawa, M. Enomoto, J. Harada, K. Ogawa, G. Maruta, S. Takeda, N. Kojima, C. Train, and M. Verdaguerg “A tricky water molecule coordinated to a verdazyl radical–iron(II) complex: a multitechnique approach” Phys. Chem. Chem. Phys., 16, 9086–9095 (2014).

Y. Takahashi, K. Hayakawa, K. Takayama, S. Yokokura, J. Harada, H. Hasegawa, and T. Inabe “Charge Conduction Properties at the Contact Interface between (Phthalocyaninato)nickel(II) and Electron Acceptor Single Crystals” Chem. Mater., 26, 993–998 (2014).


Y. Seki, A. Okazawa, M. Enomoto, J. Harada, K. Ogawa, and N. Kojima “Alternating Ferro- and Antiferromagnetic Couplings in One-Dimensional Chain Hexachlorodicuprate(II), (MV)[CuCl3]2 (MV = Methyl Viologen)Curr. Inorg. Chem., 3, 94–100 (2013).

Y. Nakagawa, Y. Takahashi, J. Harada, and T. Inabe “The bis(ethylenedithio)tetrathiafulvalene-based ionic charge-transfer complex with 2,3-dichloro-5,6-dicyano-p-benzoquinoneActa Crystallogr., Sect. C, 69, 400–402 (2013).

[Until 2012, selected]

J. Harada, K. Ueki, M. Anada, Y. Kawazoe, and K. Ogawa “Solid-State Photochromism of Chromenes: Enhanced Photocoloration and Observation of Unstable Colored Species at Low Temperatures” Chem. Eur. J., 17, 14111–14119 (2011).

J. Harada, Y. Kawazoe, and K. Ogawa “Photochromism of spiropyrans and spirooxazines in the solid state: low temperature enhances photocoloration” Chem. Commun., 46, 2593–2595 (2010).

J. Harada and K. Ogawa “Pedal motion in crystals” Chem. Soc. Rev., 38, 2244–2252 (2009).

原田 潤, 小川 桂一郎, 「有機結晶の色変化を理解する-サリチリデンアニリン類のサーモクロミズムの真相-」現代化学, 2009年,1月号,25–30.

J. Harada, R. Nakajima, and K. Ogawa “X-ray Diffraction Analysis of Photochromic Reaction of Fulgides: Crystalline State Reaction Induced by Two-Photon Excitation” J. Am. Chem. Soc., 130, 7085–7091 (2008).

J. Harada, T. Fujiwara, and K. Ogawa “Crucial Role of Fluorescence in the Solid-State Thermochromism of Salicylideneanilines” J. Am. Chem. Soc., 129, 16216–16221 (2007).

T. Fujiwara, J. Harada, and K. Ogawa “Solid-State Thermochromism Studied by Variable-Temperature Diffuse Reflectance Spectroscopy. A New Perspective on the Chromism of Salicylideneanilines” J. Phys. Chem. B, 108, 4035–4038 (2004).

J. Harada and K. Ogawa “X-ray Diffraction Analysis of Nonequilibrium States in Crystals: Observation of an Unstable Conformer in Flash-Cooled Crystals” J. Am. Chem. Soc., 126, 3539–3544 (2004).

J. Harada, and K. Ogawa “Invisible but Common Motion in Organic Crystals: A Pedal Motion in Stilbenes and Azobenzenes” J. Am. Chem. Soc., 123, 10884–10888 (2001).

J. Harada, H. Uekusa, and Y. Ohashi “X-ray Analysis of Structural Changes in Photochromic Salicylideneaniline Crystals. Solid-State Reaction Induced by Two-Photon Excitation” J. Am. Chem. Soc., 121, 5809–5810 (1999).

K. Ogawa, Y. Kasahara, Y. Ohtani, and J. Harada “Crystal Structure Change for the Thermochromy of N-Salicylideneanilines. The First Observation by X-ray DiffractionJ. Am. Chem. Soc., 120, 7107-7108 (1998).

J. Harada, K. Ogawa, and S. Tomoda “Molecular Motion and Conformational Interconversion of Azobenzenes in Crystals as Studied by X-ray DiffractionActa Crystallogr., Sect. B, 53, 662-672 (1997).

J. Harada, K. Ogawa, and S. Tomoda “The Central Bond Length in 1,2-DiphenylethanesJ. Am. Chem. Soc., 117, 4476-4478 (1995).