Shin-ichi Kuroda
Emeritus Professor, Nagoya University[Present Position]
Fellow at Toyota Physical and Chemical Research Institute[Research Field]
Solid State Physics, Magnetic Resonance, Molecular Electronics[Date of Birth]
February 4, 1950

[Sex] Male[Nationality] Japan[Graduation and Degree]
Mar. 1973 Faculty of Science (physics). Osaka University
Mar. 1975 Graduate School of Science, Master Course (physics major), Osaka University
Mar. 1978 Graduate School of Science, Doctor Course (physics major), Osaka University
Mar. 1978 Doctor of Science, Osaka University(Thesis title: Submillimeter ESR at Low Temperatures)[Professional Career]Mar. 1978 - Jan. 1979
Feb. 1979 - Mar. 1981
Apr. 1981 - Mar. 1983
Apr. 1983 - Dec. 1992
Jan. 1993 - Sep. 1996
Oct. 1996 - Mar. 2015
Apr. 2017 - Present

Yukawa Fellow, Osaka University.
Research Associate, Department of Physics and Astronomy,
University of Alabama, Tuscaloosa (USA)Researcher, Electrotechnical Laboratory
Senior Researcher, Electrotechnical Laboratory
Chief of Condensed Matter Physics Section,
Electrotechnical Laboratory
Professor, Department of Applied Physics, Nagoya
University
Fellow at Toyota Physical and Chemical Research Institute[Membership]
Physical Society of Japan, The Japan Society of Applied Physics, The Society of Electron
Spin Science and Technology, The Society of Polymer Science, Japan.

Electron Spin Resonance Studies of Organic Electronic Materials and Devices
Shin-ichi Kuroda
Overview
Organic electronics is regarded as one of the key technologies that may bring innovation
to electronics in the 21st century. Organic electronic devices such as electroluminescent(EL) displays, field-effect transistors and solar cells attract much attention as low-cost
devices with flexibility. Varieties of organic semiconducting materials based on πconjugated polymers and small molecules have been synthesized since the discovery of the
conducting polymer polyacetylene by Shikarawa, Heeger and MacDiarmid. Unpaired
electrons in these materials such as solitons and polarons carry spin and charge and play
important roles in exhibiting the functions of materials. Based on this understanding, theauthor has been engaged in the application of electron spin resonance (ESR) spectroscopy
as a powerful microscopic tool to investigate the fundamental properties of organic
electronic materials and the electronic processes in the devices by detecting the unpaired
electron spin.
Initial challenge was the studies of the nanoscale spatial extent of solitons and polarons
in conducting polymers. In particular, soliton in polyacetylene was the most fundamental
problem. By employing electron-nuclear double-resonance (ENDOR) technique, that candetermine the hyperfine coupling between the unpaired electron spin and nearby protons ina high accuracy, soliton extension close to the theoretical prediction was successfully
observed, providing strong evidence for their existence. Use of stretch-oriented samples was
essential in confirming the anisotropic properties of π-electron that played crucial role in
the ESR and ENDOR analysis. The next problem was the ENDOR studies of polarons in
the first EL polymer PPV, discovered by R. Friend, which also provided the first exampleof the confirmation of polaron extension in conducting polymers.
Studies of EL polymers opened up a new study of optically-generated polarons by using
light-induced ESR (LESR) measurements. The method was further extended to the
conducting polymer/fullerene composites and light-induced ENDOR (LENDOR) technique
was also successfully applied. Eventually, organic transistors of high-mobility polymers
such as regioregular polythiophene (RR-P3HT) attracted considerable attention. While
direct observation of charges in organic devices remained a big challenge, various opticalmethods were already introduced to such purpose but no spin detection. This motivated us
to develop a completely new ESR method, field-induced ESR (FI-ESR) method which candetect spins of the charges injected at the interface of organic transistors. First, the method

was applied to the polymer then to typical high-mobility small molecule pentacene andothers. The method has proved to be useful in clarifying electronic states, spin-charge
relation, wave functions, dynamics, and local molecular orientations, crucial for device
performance. In the following, the main results of those ESR researches on π-conjugatedpolymers and small molecular organic semiconductor materials and devices are reviewed.
1. ENDOR studies of soliton in polyacetylene
Polyacetylene attracted much attention not only due to its metallic conductivity upon
doping, but also for the soliton predicted as the nonlinear excitations in one-dimensional
electron system. The soliton in polyacetylene is a bond alternation kink where the singledouble bond alternation order is reversed by the soliton, resulting in the kink structure with
two successive single bonds and one unpaired electron that can be detected by ESR (Fig.
1(a)). The unpaired electron was predicted to be delocalized on the conjugated chain, andthe observation of its extension was one of the key problems in providing evidence for its
existence. The author proposed that ENDOR is a suitable method to observe the shape ofsoliton, by the determination of the hyperfine coupling between the unpaired electron spinand nearby protons on the conjugated chain, that can provide the spin distribution of thesoliton.
Prior to the ENDOR studies, an important prerequisite was the confirmation of the πelectron character of the unpaired electron as predicted from the molecular structure of thesoliton. Theory of the hyperfine coupling of π-electron has to be used to in the ENDOR
analysis. There were certainly the unpaired electrons observed in the polymer and they also
exhibited the motional effect as predicted from the theory, however, there were no directconfirmation of π-electron character. The author pointed that since π-electron exhibits
characteristic anisotropy in the ESR parameters such as g- and hyperfine coupling tensors,
it should be reflected on the ESR spectra if we use stretch-oriented samples. Indeed such πelectron character has been observed in stretch-oriented Shirakawa polyacetylene, in theanisotropy of ESR g-values and hyperfine-determined linewidth, confirming that theunpaired electrons in polyacetylene are π-electrons. Since then, the anisotropic propertiesof g and hyperfine coupling have been playing key roles in the analysis of physicalproperties such as molecular orientations in organic thin films and devices of π-conjugatedsystems. The research in polyacetylene has provided the starting example of such analysis.
ENDOR spectra were successfully observed down to 4K using stretch-oriented samples,
and the spectral line shape directly provides the detail of soliton spin distribution (Fig. 1(d))[1,2]. From the maximum ENDOR shift, the peak spin density ρ(0) at the center of thesoliton is obtained. Another important feature is the existence of the distinct spectral turningpoint for the spectra of parallel direction, which provides direct evidence of the existence ofthe second group of spin density, that is negative spin sites arising from the electron
correlation effect. Thus determined spin density extends over about 18 carbon sites in half
width and the detailed profile was well reproduced by the theory incorporating the effect ofelectron correlation (Fig. 1(e)). After our work, similar spin distribution was reported by the
ENDOR using stretch-oriented polyacetylene samples prepared by the method different
from Shirakawa method. From these results together with evidence of other predicted
properties, now the existence of the soliton in polyacetylene is well established.
Confirmation of the existence of soliton in polyacetylene has significant meaning in thatthe model Hamiltonian predicted soliton is essentially correct in describing the propertiesof conducting polymers, supplemented with electron correlation effect, and it thus keeps
providing a basic tool to describe the properties of π-conjugated systems used in organic
electronics. More specifically, since the majority of charge carrier, polaron in conjugatedpolymers is physically the soliton pair (one is neutral and the other is charged), soliton
provides the basis for understanding the optoelectronic properties of polymeric devices.
1) S. Kuroda, H. Bando, H. Shirakawa, J. Phys. Soc. Jpn. 54, 3956 (1985).
2) S. Kuroda, H. Shirakawa, Phys. Rev. B 35, 9380 (1987).
3) S. Kuroda, Int. J. Mod. Phys. B 9, 211 (1995) (review).
(a)

(b)

(d)

(e)

(c)

Fig. 1 (a) Soliton in polyacetylene. (b) pπ orbital of a carbon atom. (c) Anisotropic ESR
signals in stretch-oriented polyacetylene film. (d) ENDOR spectra in stretch-oriented
polyacetylene2). (e) Spin density distribution of soliton.

2. ENDOR studies of polaron in conjugated electroluminescent polymer,
poly(paraphenylene vinylene) and light-induced ESR
After the discovery of metallic conductivity in polyacetylene and other polymers, anotheroutstanding property was added to conjugated conducting polymers. That is, intenseelectroluminescence was discovered in poly(paraphenylene vinylene) (PPV). Electroluminescence occurs from the recombination of positive and negative carriers injected fromthe electrodes of the device and hence their studies are of fundamental importance. The
charge carrier, polaron, is shown in PPV structure in Fig. 2(a). When we dope the neutralpolymer, polaron as a soltion pair (one is neutral and the other is charged) is created and it
has spin 1/2 and charge +e and can be detected by ESR. Using stretch-oriented samples,
ENDOR spectra of polarons in PPV have been successfully observed [1]. The observed
spectra were well reproduced by the theory. The results revealed that the polaron extensionof about 4 phenyl rings with the maximum spin density residing on the vinyl sites (Fig. 2(b))[2]. The polaron spin distribution thus observed provided evidence for their existence.
Eventually, soluble derivatives of PPV polymer were developed for which we havecarried out LESR experiments. Comparison of LESR spectra of PPV derivatives withdifferent molecular structures enables us to obtain prominent results, that is, site-selective
information of electron distribution in PPV backbone structure [3]. According to our
ENDOR analysis, the major electron density resides on the vinyl sites. Comparison of LESR
spectra between CN-PPV where a proton on the vinyl sites is substituted by a CN group
without proton and MEH-PPV, clear decrease of hyperfine-determined LESR linewidth in
CN-PPV was observed due to the loss of the proton (Fig. 2(d)). The results were
quantitatively reproduced by the theoretical spin distribution obtained by ENDOR analysis
and gives further evidence of the validity of ENDOR study supplemented by LESR study.
1) S. Kuroda, T. Noguchi, T. Ohnishi, Phys. Rev. Lett. 72, 286 (1994).
2) Y. Shimoi, S. Abe, S. Kuroda et al, Solid State Commun. 95, 137 (1995).
3) S. Kuroda, K. Marumoto, H. Ito, N. C. Greenham, R. H. Friend, Y. Shimoi, S. Abe,
Chem. Phys. Lett. 325, 183 (2000).
(a)

(b)

(c)

(d)
MEH-PPVT = 80 K
MEH-PPVCN-PPV

CN-PPV

10 G
Magnetic Field [G]Fig. 2 (a) Polaron in an electroluminescent polymer PPV. (b) Theoretical spin
distribution of polaron in PPV2). (c) Molecular structure of MEH-PPV and CN-PPV. (d)LESR spectra of MEH-PPV and CN-PPV3).
3. LESR and LENDOR studies of conjugated polymer/fullerene composites
Regioregular poly(3-hexyl thiophene) (RR-P3HT) is a prototypical high mobility
polymer with regular attachment of alkyl chains that results in the formation of crystalline
lamellar structure on the substrate. Due to this crystallinity field-effect mobility reaches highvalue of ~0.1 cm2/Vs. Composites with fullerene become solar cell materials. Compositesof conjugated conducting polymer with fullerene exhibit highly efficient photoinduced
charge transfer (CT) suitable for solar cell materials. Due to this CT, LESR studies become
possible, however, no previous LESR existed in the case of RR-P3HT/C 60 (Fig. 3(a)) and
we have reported the first LESR signals [1]. We further measured LENDOR (Fig. 3(b)) andsucceeded in observing the spatial extent of wave functions of positive polaron of P3HT
corresponding to polaron half width of about 10 thiophene rings [2].
Furthermore, by observing the excitation light power dependence of LESR signals (Fig.
3(c)), we have discovered novel quadrimolecular recombination process that involves thesimultaneous recombination of two positive and two negative charge carriers, instead ofusual bimolecular recombination. Contribution of two positive charges strongly suggests
the formation of bipolarons (or polaron pairs) in the intermediate process of charge
recombination. Besides P3HT, we also succeeded in LESR and LENDOR measurements ofcomposites of fullerene with a blue-light emitting polymer, polyfluorene (PFO) [3].
LENDOR results showed that the half width of the polaron spin distribution in PFO wasthree PFO monomer units. In LESR, bimolecular recombination process was observed
instead of quadrimolecular recombination in P3HT. This suggests that the quadrimolecular
process is unique to regioregular polymers. As discussed in the next section, field-induced

ESR of P3HT has revealed the tendency of the formation of spinless doubly-charged state,
the occurrence of quadrimolecular recombination may be reasonably understood.
1) K. Marumoto, N. Takeuchi, T. Ozaki, S. Kuroda, Synth. Met. 129, 239 (2002).
2) S. Kuroda, K. Marumoto, T. Sakanaka, N. Takeuchi, Y. Shimoi, S. Abe, H. Kokubo, T.
Yamamoto, Chem. Phys. Lett. 435, 273 (2007).
3) K. Marumoto, M. Kato, H. Kondo, S. Kuroda, N.C. Greenham, R.H. Friend, Y. Shimoi,
S. Abe, Phys. Rev. B 79, 245204 (1-11) (2009).
(b)

(a)

(c)

Ipr (arb. units)

0.25

105

Iex

Iex0.5104

λ = 700 nm

0.01

0.05 0.1
Iex (mW/cm2)

0.5

1

Fig. 3 (a) Molecular structure of P3AT/C 60 composite. (b) LENDOR signals of P3AT /C 60
composites. (c) Excitation power dependence of LESR signals.
4. Development of field-induced ESR spectroscopy – A new method for in-situ
observation of charge carriers in organic transistors
4-1. Initial development of field-induced ESR - Observation of polarons in field-effectdevices of polyalkylthiophene
In organic field-effect devices such as organic transistors, charge carriers are accumulated
at the semiconductor/insulator interface and exhibit transport. There have been precedingstudies in detecting such interfacial carriers using various kinds of optical spectroscopic
methods. On the other hand, however, there were no report of the detection of spins ofinterfacial carriers. By constructing field-effect devices suitable for ESR measurements
using P3HT as a semiconductor, we have been successful in observing the first field-induced
ESR (FI-ESR) signals of polarons injected at the semiconductor/insulator interface [1, 2].

The device structure of the first successful ESR measurements was a Metal-InsulatorSemiconductor (MIS) diode fabricated on a quartz glass substrate with vapor-deposited Al
gate electrode, sputtered Al 2 O 3 gate insulator and a drop cast film of the polymer with top
Au electrode (Fig. 4(a)). Since P3HT is a p-type semiconducting material, upon applying
negative gate bias, positive carriers are accumulated at the device interface and their ESR
signals have been detected for the first time (Fig. 4(b)). The g-value of FI-ESR signals
coincided well with those of positive polarons observed by light-induced ESR of P3HT/C 60
composites (Fig. 4(b)), providing evidence that the detected field-induced ESR signals
originate from P3HT. In addition, when we rotate the device under the magnetic field, both
the g-value and hyperfine-determined linewidth exhibited clear angular dependence, which
directly shows the edge-on orientation of the polymer plane consistent with the formation
lamellar crystalline structure at the device interface, as in Fig. 4(c).
Furthermore, the number of spins obtained from ESR signal and the number of charges
calculated from the capacitance of the device coincided well, when the gate bias was low,
showing that all the injected charge has spin, that is, polarons (Fig. 4(d)). By increasing thegate bias, however, spin number tends to show saturation, suggesting the formation of
spinless bipolarons (or polaron pairs) as a carrier species. From those results, it has become
clear that field-induced ESR signals provide the information concerning electronic and spinstates and interfacial molecular orientation, which are crucial in determining the device
performance.
1) K. Marumoto, Y. Muramatsu, S. Ukai, H. Ito and S. Kuroda, J. Phys. Soc. Jpn. 73, 16731676 (2004).
2) K. Marumoto, Y. Muramatsu, Y. Nagano, T. Iwata, S. Ukai, H. Ito, S. Kuroda, Y. Shimoi
and S. Abe, J. Phys. Soc. Jpn. 74, 3066-3076 (2005).
(a)

(b)

8

(d)

8

6

6

4

4

2
0
0

Nspin
Ncharge-20-10Gate Bias (V)-30

Ncharge (1011)

RR-P3HT

Nspin (1011)

(c)

2
0

Fig. 4 (a) Schematic structure of a MIS diode for ESR measurements. (b) Comparison
between the field-induced ESR signal of P3HT and light-induced ESR signal of P3HT/C 60
composite2). (c) Molecular orientation of P3HT at the device interface. (d) Spin-charge
relation of a MIS diode of P3HT2).
4-2. ESR of pentacene transistors and spatial extent of wave function of polaron
FI-ESR started from MIS diode structure of P3HT. In the case of typical high-mobility
small molecule, pentacene, we have fabricated field-effect transistor (FET) structure for FIESR and clear ESR signals have been successfully observed as in Fig. 5(a) [1]. The numberof spin and the number of charge coincided well, showing the charges are polarons withspin. No spin saturation was observed in pentacene, contrary to the case of RR-P3HT, shown
above. Angular dependence of g-value and hyperfine-determined ESR linewidth clearly
showed the end-on type molecular orientation at the device interface (Fig. 5(b)).
Most striking result obtained from this study was the spatial extent of gate-induced
positive polarons. Conventional picture of charge transport of pentacene was hoppingtransport of charge carriers localized on single molecule. From the analysis of hyperfinedetermined ESR line width, spatial extent of polaron wave function was estimated to beabout 10 molecules. This provided the first microscopic evidence for the band-like transport
in the case of high-mobility small molecule.
FI-ESR method was adopted in other research groups, for example for pentacenetransistors to study carrier dynamics. These results establish that the field-induced ESR is a
new spectroscopic technique to probe the charge carriers at the interface of organic
transistors by the detection of spin.
1) K. Marumoto, S. Kuroda, T. Takenobu and Y. Iwasa, Phys. Rev. Lett. 97, 256603-1256603-4 (2006).
2) H. Tanaka, M. Hirate, S. Watanabe, K. Kaneko, K. Marumoto, T. Takenobu, Y. Iwasa,
and S. Kuroda, Phys. Rev. B 87, 045309-1-4 (2013)

(a)

(b)

Fig.5 (a) FI-ESR signal of pentacene transistor and inset shows spin-charge relation1).
Orientation of pentacene molecule at the device interface1).

(b)4-3. ESR of uniaxially aligned ultrathin polymeric transistors
Fabrication of polymeric transistors with uniaxially aligned polymer chain axis may
attract interest both from the applications and basic studies of materials properties. As afabrication method of such transistors, we have adopted Langmuir-Blodgett (LB) methodthat can fabricate ultrathin films by layer-by-layer depositions of a monolayer film formedon the water surface. By using newly developed LB technique employing co-spreading
mixed solution of P3HT and a liquid-crystalline molecule on the water surface, andsubsequent uniaxial compression orientation of monolayer film, uniaxially-aligned ultrathinmonolayer transistors of P3HT were fabricated as shown in Fig. 6(a) [1]. For ESR
measurements, we used low-doped SiO 2 /n+-Si substrates that we have developed for FIESR, which do not deteriorate the Q-value of ESR sample cavity. Monolayer transistors
showed good mobilities comparable to conventional P3HT transistors, providing evidence
that the active layer thickness of charge transport is indeed single monolayer. The mobility
along the chain direction was about two times larger than that of perpendicular direction.
This weak anisotropy may be ascribed to the quasi two-dimensional charge transport
resulting from the development of π- π stacking in a lamellar structure of P3HT.
Figure 6(b) shows the anisotropy of ESR signals in the two types of devices with different
preferential chain orientations, the upper and lower curves with the chain direction
perpendicular and parallel to the source-to-drain axis on the substrate, respectively. In
particular, the g value along the chain direction (g y ) takes a minimum value, which was well
reproduced from the DFT calculation. Using a spectrum simulation method, asymmetric
ESR line shapes of the parallel and perpendicular chain orientations were well reproduced,

from which the in-plane orientation distribution function of the chain axis was quantitatively
determined. The results well explained the observed dichroic ratio determined by polarized
optical absorption measurements of P3HT ultrathin films. Thus by using of uniaxiallyaligned thin-film transistor structures, orthorhombic principal g-values of the P3HT chain
were directly resolved for the first time, successfully showing the preferential in-planeorientation of the chain axes by a microscopic measurement.
1) S. Watanabe, H. Tanaka, S. Kuroda, A. Toda, S. Nagano, T. Seki et al., Appl. Phys. Lett.
96, 173302-1-3 (2010).
(a)

(b)

Fig. 6 (a) Schematic structure of monolayer organic transistor of P3HT1). (b) ESR signal
anisotropy in two kinds of ultrathin FET devices of P3HT with in-plane preferential chainorientations1). The upper signals corresponds to the device structure with the chainorientation perpendicular to the channel direction (source and drain direction) and the lower
ones to that with the chain parallel to the channel direction.
4-4. Low-temperature ESR of thienothiophene-based high-mobility small molecules
Thienothiophene-based molecules are typical high-mobility small molecules with highcrystallinity, resulting from the strong intermolecular interaction through the sulfur atomsof thienothiophene base. C 10 -DNTT is a typical thienothiophene-based high-mobility
molecule of which field-effect transistors exhibit mobilities higher than 1cm2/Vs even inpolycrystalline thin-film devices. Molecular structure of C 10 -DNTT is shown in Fig. 7(a).
To understand the transport mechanism of such high-mobility system, low-temperature
carrier dynamics generally is an important issue, however, transport measurements become
difficult at low temperatures due to the charge carrier trapping at grain boundaries. On theother hand, field-induced ESR can be measured regardless of grain boundaries [1], and ESR
reveals the carrier motion even at 4K within the crystalline grains.

FI-ESR signals of C 10 -DNTT thin-film transistors on SiO 2 /n+-Si substrates wereobserved down to 4K [2]. FI-ESR spectra at 4K shows a clear angular dependence as in Fig.
7(b) where Θ denotes the angle between the external field and the normal direction of thesubstrate. ESR separates intra and intergrain motion from the motional effect of ESR signals
depending on the magnetic field orientation. ESR at perpendicular direction (Θ = 0º) shownat the bottom of Fig. 7(b), all the crystalline grains make the same angle with the magnetic
field, giving single ESR line (g y ) and yields the intragrain information. On the other hand,
ESR at parallel direction (Θ = 90º) at the top of Fig. 7(b), randomly oriented grains gives
two-dimensional powder ESR pattern (g x and g z ) and yields intergrain information.
Anisotropy of principal g-values in Fig. 7 (b) were well reproduced by DFT calculation.
Angular dependence of ESR signal was further reproduced well by spectrum simulation,from which the end-on molecular orientation (Fig. 7(a)) with very low angular fluctuation(<0.5°) has been revealed, showing that highly organized orientational order exists at thedevice interface. This may be one of the reasons for the high carrier mobility.
As for intragrain motion, sharp Lorentzian line shape characteristic of motional narrowing
at Θ = 0º signal gives direct evidence for the carrier motion within grain even at 4K. On
the other hand, considerably low activation energy of intergrain motion was found from thetemperature dependence of the ESR signal of parallel direction shown in Fig. 7(c). In the
figure, typical motional narrowing phenomenon, that is, the static powder ESR spectra of
two resolved peaks at 4K are drastically narrowed into a single resonance line at higher
temperatures. From the analysis of the temperature dependent motional narrowing effect of
the ESR signal, the activation energy of intergrain motion as low as 10 meV has been
revealed. This value coincided well with the activation energy of about 10meV for FET
mobility, of which temperature dependence is shown in the inset of Fig. 7(c). Suchcoincidence shows the microscopic origin of the activation energy of FET mobility
governed by grain boundaries. This value may be one of the lowest values ever reported forthe activation energy of FET mobility of organic transistors.
Finally, the spatial extent of the carrier wave function is of much interest in view of thosehighly mobile nature of charge carriers in C 10 -DNTT. The observed ESR linewidth in thestatic limit indicates the extension ~100 molecules, much more delocalized in the case ofpentacene of ~10 molecules. Such difference may be related to more flexible crystalline
structure of pentacene, as discussed in the structural and Hall-effect measurements.
1) H. Tanaka, M. Kozuka, S. Watanabe, H. Ito, Y. Shimoi, K. Takimiya, S. Kuroda, Phys.
Rev. B 84, 081306-1-4 (R) (2011).
2) Y. Kinoshita, H. Tanaka, Y. Shimoi, K. Takimiya and S. Kuroda, Appl. Phys. Lett. 105,
033301-1-5 (2014).

(a)

(b)

(c)

Fig. 7 (a) Molecular structure of C 10 DNTT and the end-on molecular orientation at thedevice interface. (b) Angular dependence of ESR spectra of C 10 DNTT (dotted line)2) . The
angle Θ shows that between the external field and the normal direction of the substrate as
shown in Fig. 7(a). Calculated ESR spectra are shown by solid line. (c) Temperaturedependence of the ESR signals with the external field parallel to the substrate2). Inset shows
the temperature dependence of the field-effect mobility.
5. ESR of charge carriers in semicrystalline polymer PBTTT induced by chemical
doping or ionic-liquid-gated transistor structures.
To date, many conducting polymers have been synthesized as new polymericsemiconducting materials aiming for the development of organic electronic devices.
Recently, highly-doped state of semicrystalline conjugated polymers attract attention not
only from the development of metallic conductivity, but also from thermoelectric
applications. Concerning the metallic transition process, however, despite theoreticalpredictions about the change of electronic states of the carriers from polarons, via bipolarons
to metallic state by doping (Fig. 8(a)), clear experimental evidence for such phenomena has
not yet been well established. Since bipolaron is a doubly charged state without spin (Q=±2e,
S=0), we have been recently successful in showing that ESR is a suitable method todiscriminate spinless bipolarons from polarons, by probing whether the charges induced bydoping in semicrystalline polymers are ESR detectable or not.
In a semicrystalline conjugated polymer PBTTT, appearance of high conductivity in thinfilms by chemical doping using a fluoro-alkylsilane (FTS) molecules attracted considerable
attention. We have carried out simultaneous measurements of conductivity and ESR usingthin-film samples and successfully detected Pauli spin susceptibility characteristic of metals
only in the crystalline domains with edge-on molecular orientations (Fig. 8(b)), providing
microscopic evidence for the realization of metallic state in semicrystalline polymers [1].
More recently, we have succeeded in observing high conductivities and at the same timea metallic temperature dependence for certain temperature range by reversible
electrochemical doping using ionic-liquid-gated transistor structures. Then we proceeded toconstruct ionic-liquid-gated transistor structures suitable for ESR measurements (Fig. 8(c))
and clearly observed ESR signals as in Fig. 8(e), showing the appearance of spinlessbipolarons in high doping levels from the spin susceptibility [2]. By increasing the doping
level, a clear decrease of spin numbers was observed while the charge numbers kept
increasing as shown in Fig. 8(f). Bipolaron formation was also supported by the change of
optical absorption upon electrochemical doping by ionic-liquid gating (Fig. 8(d)). In
addition, angular dependence of ESR line width at high-doping regimes clarified theappearance of spin relaxation characteristic of conduction electrons (Elliott type). On theother hand, g-value anisotropy confirmed the edge-on molecular orientation was maintained
up to the highest doping levels, showing the robust structure of the semicrystalline polymer.
Furthermore, by using bilayer films of F 4 -TCNQ and PBTTT, a solid state diffusion of
F 4 -TCNQ into PBTTT films was found to take place, resulting in the appearance of Paulisusceptibility together with the observation of nearly ideal Hall effect at low temperatures,providing clear evidence for metallic transition in PBTTT films [3].
These results indicate that the control of electronic states from polarons via bipolarons tometallic state are becoming possible by reversible electrochemical doping process. Further
studies of these electronic state transitions in other semicrystalline conjugated conducting
polymers may contribute, for example, to deepen the understanding the electronic states ofconjugated polymers and the development of their control methods.
1) H. Tanaka. M. Hirate, S. Watanabe, and S. Kuroda, Adv. Mater. 26, 2376 (2014).
2) H. Tanaka, S. Nishio, H. Ito, and S. Kuroda, Appl. Phys. Lett. 107, 243302 (2015).
3) K. Kang, S. Watanabe, H. Tanaka, S. Kuroda, H. Sirringhaus et al., Nature Mater. 15,
896-902 (2016).
(a)

(b)

(c)

(f)

g=2.00315
H⊥substrate
3410

3420
3430
Magnetic Field (G)

344

1020

Charge
Spin

101

1019

100

1018

10-1
0.5

0

-0.5
Vg (V)-1

Doping Level (%)

VG
0V
-0.4V
-0.8V
-1.0V

Density (cm-3)

ESR Intensity(a.u)

(e)

(d)

-1.5

Fig. 8 (a) Polaron and bipolaron in P3HT. (b) Molecular structure of a semicrystalline
polymer, PBTTT and edge-on molecular orientation at the device interface. (c) Schematic
structure of an ionic-liquid-gated organic transistor. (d) Gate-bias dependence of opticalabsorption spectra of an ionic-liquid-gated MIS diode of PBTTT2). (e) Gate-bias
dependence of ESR signals in an ionic-liquid-gated transistor of PBTTT2). (f) Spin-charge
relation of ionic-liquid-gated transistors of PBTTT2).

Publication List
Shin-ichi Kuroda
Original Papers
1. M. Date, M. Motokawa, H. Hori, S. Kuroda and K. Matsui
Is CTS a one-dimensional magnet?”
J. Phys. Soc. Jpn.. 39, 257-258 (1975)
2. M. Date, M. Motokawa, A. Seki, S. Kuroda, K. Matsui, H. Nakazato and H. Mollymoto
Submillimeter electron-spin resonance 2. Megagauss magnets and ESR in CuCl 2 2H 2 O”
J. Phys. Soc. Jpn.. 39, 898-904 (1975).
3. S. Kuroda, M. Motokawa and M. Date
SH3 term in submillimeter electron spin resonance of cobalt Tutton salt
J. Phys. Soc. Jpn. 44, 1797-1803 (1978).
4. M. Motokawa, S. Kuroda, and M. Date
Submillimeter electron spin resonance experiments using pulsed high magnetic field
J. Appl. Phys. 50, 7762-7767 (1979).
5. J. Haynes, S. Kuroda, K. Matsuki and I. Miyagawa
Electron spin resonance and ENDOR studies of X-irradiated n-acetyl-d,l-alanine
Radiation Res. 84, 426-433 (1981).
6. S. Kuroda, M. Tokumoto, N. Kinoshita, and H. Shirakawa
p-π electron character observed through the anisotropy of electron spin resonance in undoped(CH) xJ. Phys. Soc. Jpn. 51, 693-694 (1982).
7. S. Kuroda, and H. Shirakawa
π-electron character observed through the anisotropy in the ENDOR spectra of undoped (CH) x
Solid State Commun. 43, 591-594 (1982).
8. S. Kuroda, and I. Miyagawa
ENDOR study of an irradiated crystal of l-alanine – environment of the stable CH 3 CHCO 2 (-)
radicalJ. Chem. Phys. 76, 3933-3944 (1982).
9. S. Kuroda, M. Sugi, and S. Iizima
Electron spin resonance of Langmuir films of merocyanine dyes
Thin Solid Films 99, 21-24 (1983).
10. S. Kuroda, M. Tokumoto, N. Kinoshita, T. Ishiguro and H. Shirakawa
π-electron character observed through the anisotropy of the magnetic resonance spectra inundoped (CH) x
J. Magn. Magn. Mater. 31-4, 1149-1150 (1983).
11. S. Yamasaki, S. Kuroda, and K. Tanaka
ENDOR study of a-Si:H
J. Non-Cryst. Solids 59, 141-144 (1983).
12. S. Yamasaki, S. Kuroda, K. Tanaka and S. HayashiHyperfine interaction between hydrogens and dangling bonds in a-Si:H studied by ENDOR
Solid State Commun. 50, 9-11 (1984).
13. S. Kuroda, H. Bando, and H. Shirakawa
Direct observation of soliton-like spin density distribution in undoped cis-rich (CH) x by
ENDOR at 4K
Solid State Commun. 52, 893-897 (1984).
14. S. Kuroda, H. Bando, and H. Shirakawa
Direct observation of soliton-like spin density distribution in undoped cis-rich (CH) x using
ENDOR
J. Phys. Soc. Jpn. 54, 3956-3965 (1985).
15. S. Yamasaki, S. Kuroda, H. Okushi and H. Tanaka
Energy location of ESR hyperfine centers of P-doped a-Si:H
J. Non-Cryst. Solids 77-8, 339-342 (1985).
16. S. Yamasaki, S. Kuroda, J. Isoya, H. Okushi and K. Tanaka
ENDOR and ESEEM study of phosphorus-doped a-Si:H
J. Non-Cryst. Solids 77-8, 727-730 (1985).
17. S. Kuroda, Y. Kurita, and I. Miyagawa
A new effect of ionizing irradiation – anisotropic expansion of a peptide crystal
Radiation Res. 104, 116-118 (1985).
18. S. Kuroda, M. Sugi, and S. Iizima
Origin of stable spin species in Langmuir-Blodgett films of merocyanine dyes studied byelectron spin resonance and ENDOR
Thin Solid Films 133, 189-196 (1985).
19. H. Oyanagi, M. Sugi, S. Kuroda, S. Iizima and T. Ishiguro
Polarized X-ray absorption spectra of Langmuir-Blodgett films – local structure studies ofmerocyanine dyes
Thin Solid Films 133, 181-188 (1985).
20. S. Kuroda, K. Ikegami, M. Sugi and S. Iizima
Direct observation of in-plane molecular alignment in LB films of a merocynaine dye using
electron spin resonance
Solid State Commun. 58, 493-497 (1986).
21. S. Kuroda, and H. Shirakawa
Harmonics of 13C nuclear frequency observed by endor in 13C-enriched cis-rich (CH) x andreinterpretation of the spectra
Solid State Commun. 59, 261-265 (1986).
22. M. Yoneyama, M. Sugi, M. Saito, K. Ikegami, S. Kuroda, and S. Iizima
Photoelectric properties of copper phthalocyanine Langmuir-Blodgett films
Jpn. J. Appl. Phys 1, 25, 961-965 (1986).
23. S. Kuroda, I. Murase, T. Ohnishi and T. Noguchi
Electron spin resonance and ENDOR study of poly(phenylene vinylene)”
Synthetic Met. 17, 663-666 (1987).
24. S. Kuroda, and H. Shirakawa

Soliton spin density in polyacetylene studied by ENDOR in pristine and 13C-enriched cis-richsampleSynthetic Met. 17, 423-428 (1987).
25. K. Ikegami, S. Kuroda, M. Sugi, M. Saito, S. Iizima, T. Nakamura, M. Matsumoto, Y. Kawabata,and G. Saito
Electron spin resonance study on LB films of TMTTF-OctadecylTCNQ
Synthetic Met. 19, 669-674 (1987).
26. K. Ikegami, S. Kuroda, M. Saito, K. Saito, M. Sugi, T. Nakamura, M. Matsumoto, and Y.
Kawabata
Random-exchange Heisenberg anitiferromagnetic chains in Langmuir-Blodgett films of
N-docosylpyridinium-bistetracyanoquinodimethane
Phys. Rev. B 35, 3667-3670 (1987).
27. S. Yamasaki, M. Kaneiwa, S. Kuroda, H. Okushi and K. Tanaka
1-H electron-nuclear double-resonance detected electron spin resonance of light-soaked
undoped a-Si:H
Phys. Rev. B 35, 6471-6474 (1987).
28. S. Kuroda, and H. Shirakawa
Electron-nuclear double-resonance evidence for the soliton wave function in polyacetylene
Phys. Rev. B 35, 9380-9382 (1987).
29. K. Saito, M. Saito, K. Ikegami, and M. Sugi
Modification of diacetylene LB films by acid and basic vapor treatments before polymerization
Jpn. J. Appl. Phys. 2 26, L539-540 (1987).
30. S. Kuroda, K. Ikegami, K. Saito, M. Saito, and M. Sugi
Stable radical species in Langmuir-Blodgett films of merocyniane dyes studied by electron spinresonance
J. Phys. Soc. Jpn. 56, 3319-3332 (1987).
31. S. Yamasaki, S. Kuroda, J. Isoya and K. Tanaka
1
H-ENDOR-detected electron spin resonance spectra of P-doped and B-doped a-Si:H
J. Noncryst. Solids 97-8, 691-694 (1987).
32. N. Minari, K. Ikegami, S. Kuroda, K. Saito, M. Saito, and M. Sugi
Analytical model of flow dichroism in Langmuir-Blodgett films
Solid State Commun. 65, 1259-1262 (1988).
33. K. Saito, M. Saito, K. Ikegami, S. Kuroda, and M. Sugi
Effect of secondary treatments on the phase transition of polydiacetylene LB films
Jpn. J. Appl. Phys. 1 27, 1038-1041 (1988).
34. H. Oyanagi, M. Yoneyama, K. Ikegami, M. Sugi, S. Kuroda, T. Ishiguro and T. Matsushita
Langmuir-Blodgett monolayers studied by surface sensitive X-ray absorpition fine structureThin Solid Films 159, 435-442 (1988).
35. S. Kuroda, K. Ikegami, K. Saito, M. Saito, and M. Sugi
Characterization of in-plane and out-of-plane molecular orientation in Langmuir-Blodgett filmsof merocyanine dyes using electron spin resonanceThin Solid Films 159, 285-291 (1988).
36. K. Ikegami, S. Kuroda, M. Saito, K. Saito, M. Sugi, T. Nakamura, M. Matsumoto, and Y.
Kawabata
Electronspinresonance
studyofLangmuir-Blodgett
filmsofn-docosylpyridinium-di(tetracyanoquinodimethane)Thin Solid Films 160, 139-143 (1988).
37. M. Matsumoto, T. Nakamura, E. Manda, Y. Kawabata, K. Ikegami, S. Kuroda, M. Sugi and G.

SaitoHighly conducting Langmuir-Blodgett films of the TMTTF CNTCNQ system
Thin Solid Films 160, 61-66 (1988).
38. H. Okumura, M. Shinohara, S. Kuroda, K. Endo, E. Sakuma, S. Misawa and S. Yoshida
The origin of residual carriers in CVD-grown 3C-SiC
Jpn. J. Appl. Phys. 1 27, 1712-1717 (1988).
39. K. Ikegami, S. Kuroda, K. Saito, M. Saito, M. Sugi, T. Nakamura, M. Matsumoto, Y. Kawabata,and G. Saito
Anomalous
low-temperature
behaviorofLangmuir-Blodgett
films
of(TMTTF) 3 -(teradecylTCNQ) 2
Synthetic Met. 27, B587-592 (1988).
40. N. Minari, K. Ikegami, S. Kuroda, K. Saito, M. Saito, and M. Sugi
Origin of the in-plane anisotropy in Langmuir-Blodgett films
J. Phys. Soc. Jpn. 58, 222-231 (1989).
41. S. Kuroda, K. Ikegami, K. Saito, M. Saito, M. Sugi, S. Suga, and S. Yasui
Locally resolved electron spin resonance spectra in Langmuir-Blodgett films of a merocyaninedye
Solid State Commun. 71, 333-336 (1989).
42. S. Kuroda, K. Ikegami, K. Saito, M. Saito, and M. Sugi
Correlation between electron spin resonance and optical anisotropy in Langmuir-Blodgett filmsof merocyanine dyeThin Solid Films 178, 555-561 (1989).
43. M. Sugi, N. Minari, K. Ikegami, S. Kuroda, K. Saito, and M. Saito
Vertical dipping method as a means of controlling the in-plane molecular orientation in
Langmuir-Blodgett films
Thin Solid Films 178, 157-164 (1989).
44. K. Saito, K. Ikegami, S. Kuroda, M. Saito, and M. Sugi
In-plane anisotropy of interface-adsorbed complex Langmuir-Blodgett films
Thin Solid Films 179, 369-374 (1989).
45. K. Ikegami, S. Kuroda, K. Saito, M. Saito, M. Sugi, T. Nakamura, H. Tachibana, M. Matsumoto,and Y. Kawabata
Electron spin resonance study of Langmuir-Blodgett films of the complexes of alkylammonium
and metal(dmit) 2 anion
Thin Solid Films 179, 245-250 (1989).
46. K. Ikegami, S. Kuroda, K. Saito, M. Saito, M. Sugi, T. Nakamura, M. Matsumoto, Y. Kawabata,and G. Saito
Anomalous linewidth of electron spin resonance in Langmuir-Blodgett films of the 3-2 complex
of tetramethyltetrathiafulvalene and tetradecdyltetracyanoquinodimethane”
Thin Solid Films 179, 177-182 (1989).
47. K. Saito, K. Ikegami, S. Kuroda, M. Saito, Y. Tabe, and M. Sugi
Davydov splitting in arachidic acid cyanine dye complex Langmuir-Blodgett films
J. Appl. Phys. 68, 1968-1974 (1990).
48. Y. Tabe, K. Ikegami, S. Kuroda, K. Saito, M. Saito, and M. Sugi
In-plane anisotropy in batch-produced Langmuir-Blodgett films – side-by-side and face-to-facearrays”
Appl. Phys. Lett. 57, 1191-1193 (1990).
49. S. Kuroda, K. Ikegami, M. Sugi
ESR and ENDOR studies of functional LB films
Mol. Cryst. Liq. Cryst. 190, 111-132 (1990).

50. M. Saito, Y. Tabe, K. Saito, K. Ikegami, S. Kuroda, and M. Sugi
Acid vapor treatment of fatty-acid salt LB films – evidence for conservation of the lamellar
structureJpn. J. Appl. Phys. 2 29, L1892-1894 (1990).
51. K. Ikegami, S. Kuroda, Y. Tabe, K. Saito, M. Saito, M. Sugi, T. Nakamura, H. Tachibana, and Y.
Kawabata
Random-exchange Heisenberg AF chains in Langmuir-Blodgett films of amphiphilic
charge-transfer complexes
J. Magn. Magn. Mater. 90-1, 239-240 (1990).
52. S. Kuroda, and H. Shirakawa
Electron-nuclear-nuclear triple resonance of cis-rich polyacetylene – evidence for negative spinsites of soliton
Solid State Commun. 77, 937-941 (1991).
53. M. Saito, K. Ikegami, Y. Tabe, K. Saito, S. Kuroda, and M. Sugi
Kinetics of metal-ion liberation by acid treatment in fatty-acid salt Langmuir-Blodgett films
Jpn. J. Appl. Phys 2 30, L511-513 (1991).
54. S. Kuroda, K. Ikegami, Y. Tabe, K. Saito, M. Saito, and M. Sugi
Electron spin resonance of stable radicals in Langmuir-Blodgett films of a merocyanine dye –study of hyperfine coupling using a 15N-enriched dye
Phys. Rev. B 43, 2531-2540 (1991).
55. K. Saito, K. Ikegami, S. Kuroda, M. Saito, Y. Yabe, and M. Sugi
Modification of aggregate formation in arachidic-acid-cyanine-dye complex Langmuir-Blodgett
films by substituent groups
J. Appl. Phys. 69, 8291-8297 (1991).
56. Y. Tabe, M. Sugi, K. Ikegami, S. Kuroda, K. Saito, and M. Saito
Flow orientation effect in batch-produced Langmuir-Blodgett films – observation of theunsteady flow around the stagnation point
J. Appl. Phys. 70, 1425-1432 (1991).
57. K. Saito, K. Ikegami, S. Kuroda, Y. Tabe, and M. Sugi
Formation of herringbone structure with Davydov splitting in cyanine dye-adsorbed
Langmuir-Blodgett films
Jpn. J. Appl. Phys. 1 30, 1836-1840 (1991).
58. T. Matsushita, A. Iida, K. Takeshita, K. Saito, S. Kuroda, H. Oyanagi, M. Sugi and Y. Furukawa
Grazing incidence X-ray diffraction study of arachidic acid monlayer on cyanine dye aqueous
solution
Jpn. J. Appl. Phys. 2 30, L1674-L1677 (1991).
59. K. Saito, K. Ikegami, S. Kuroda, Y. Tabe, and M. Sugi
Substituent-dependent self-assembly – 2-dimensional aggregate formation in cyanine
dye-adsorbed Langmuir-Blodgett films
J. Appl. Phys. 71, 1401-1406 (1992).
60. S. Kuroda, M. Motokawa, and M. Date
Electron spin resonance of exchange-coupled inequivalent spins at low temperatures and highfields – H/T effect in exchange splitting
J. Phys. Soc. Jpn. 61, 1036-1048 (1992).
61. K. Ikegami, S. Kuroda, Y. Tabe, K. Saito, M. Saito, M. Sugi, T. Nakamura, H. Tachibana, M.
Matsumoto, and Y. Kawabata
Molecular orientation in conductive Langmuir-Blodgett films of a charge-transfer complex
Thin Solid Films 210, 303-305 (1992).
62. Y. Tabe, M. Sugi, K. Ikegami, S. Kuroda, K. Saito, and M. Saito

Theory of follow orientation effects in Langmuir-Blodgett films – examination of the local
thermal equilibrium approximation
Thin Solid Films 210, 32-35 (1992).
63. S. Kuroda, K. Ikegami, Y. Tabe, K. Saito, M. Saito, M. Sugi, and S. Yasui
Electron spin resonance in Langmuir-Blodgett films of a merocyanine dye and its
isotope-substituted analogs
Thin Solid Films 210, 512-514 (1992).
64. K. Ikegami, S. Kuroda, Y. Tabe, K. Saito, M. Sugi, M. Matsumoto, T. Nakamura, and Y.
Kawabata
Flow orientation in Langmuir-Blodgett films of a charge-transfer complex(TMTTF) 3 (C 14 TCNQ) 2
Jpn. J. Appl. Phys. 1 31, 1206-1212 (1992).
65. S. Kuroda, and H. Shirakawa
Electron-nuclear double-resonance studies of pristine and 13C-enriched polyacetylene”
J. Phys. Soc. Jpn. 61, 2930-2942 (1992).
66. K. Ikegami, S. Kuroda, M. Sugi, T. Nakamura, H. Tachibana, M. Matsumoto, and Y. Kawabata
Quasi-one-dimensional spin system in Langmuir-Blodgett films of a charge-transfer complex
J. Phys. Soc. Jpn. 61, 3752-3765 (1992).
67. R. Azumi, M. Matsumoto, Y. Kawabata, S. Kuroda, M. Sugi, L.G. King and M.J. Crossley
A new method for controlling the orientation of functional molecules in Langmuir-Blodgett
films
J. Am. Chem. Soc. 114, 10662-10663 (1992).
68. K. Ikegami, S. Kuroda, M. Sugi, T. Nakamura, M. Matsumoto, H. Tachibana, and Y. Kawabata
ESR analysis of columnar structure in conductive LB films of TCNQ salts with alkylpyridinium
and its derivatives
Synthetic Met. 56, 1899-1904 (1993).
69. S. Kuroda
Characterization of Langmuir-Blodgett films using electron spin resonance spectroscopy
Collids and Surf. A 72, 127-141 (1993).
70. R. Azumi, M. Matsumoto, Y. Kawabata, S. Kuroda, M. Sugi, L.G. King and M.J. Crossley
Orientation change of porphyrin in Langmuir-Blodgett films caused by a trigger molecule
J. Phys. Chem. 97, 12862-12869 (1993).
71. S. Kuroda, T. Noguch, and T. OhnishiElectron-nuclear double-resonance observation of π-electron defect states in undopedpoly(paraphenylene vinylene)
Phys. Rev. Lett. 72, 286-289 (1994).
72. R. Azumi, M. Tanaka, M. Matsumoto, S. Kuroda, M. Sugi, T.H. Le, and M.J.Crossley
Orientation control of functional molecules in Langmuir-Blodgett films using a triggter
molecule – the effect of substitution of the functional moleculeThin Solid Films 242, 300-303 (1994).
73. S. Kuroda, K. Ikegami, K. Saito, and M. Sugi
Modification of the local structures of dye aggregates in Langmuir-Blodgett films as probed byelectron spin resonanceThin Solid Films 242, 96-99 (1994).
74. K. Ikegami, S. Kuroda, M. Sugi, H. Tachibana, T. Nakamura, and M. Matsumoto
One-dimensional columnar structure in conductive Langmuir-Blodgett films of long-chain
pyridinium-(TCNQ) 2 salts studied by electron spin resonanceThin Solid Films 242, 11-15 (1994).
75. K. Ikegami, S. Kuroda, T. Nakamura, G. Yunome, M. Matsumoto, S. Horiuchi, H. Yamochi, andG. Saito
Conduction-electron spin resonance in Langmuir-Blodgett films of a charge-transfer complex
Phys. Rev. B 49, 10806-10809 (1994).
76. S. Kuroda, T. Noguchi, and T. Ohnishi
ENDOR spectroscopy of poly(paraphenylene vinylene)
Synthetic Met. 69, 423-424 (1995).
77. S. Kuroda
Electron-nuclear double-resonance spectroscopy of solitons and polarons in conjugatedpolymers
Int. J. Mod. Phys. B 9, 221-260 (1995).
78. K. Ikegami, S. Kuroda, T. Nakamura, G. Yunome, M. Matsumoto, S. Horiuchi, H. Yamochi, and
G. Saito
ESR study of the LB films containing metallic domains
Synthetic Met. 71, 1909-1912 (1995).
79. S. Kuroda, K. Murata, T. Ohnishi and T. Noguchi
Electron-nuclear double-resonance studies ofpoly(paraphenylene vinylene)
J. Phys. Soc. Jpn. 64, 1363-1370 (1995).

π-electron

defectstatesinundoped80. Y. Shimoi, S. Abe, S. Kuroda, and K. Murata
Polarons and their ENDOR spectra in poly(paraphenylene vinylene)
Solid State Commun. 95, 137-141 (1995).
81. K. Ikegami, S. Kuroda, M. Matsumoto, and T. Nakamura
Alkali-metal doping of Langmuir-Blodgett films of C 60 studied by ESR
Jpn. J. Appl. Phys. 2 34, L1227-1229 (1995).
82. R. Azumi, M. Matsumoto, S. Kuroda, L.G. King and M.J. Crossley
Orientation change of dimer-type porphyrin in Langmuir-Blodgett films caused by a trigger
molecule
Langmuir 11, 4056-4060 (1995).
83. R. Azumi, M. Matsumoto, S. Kuroda, L.G. King and M.J. Crossley
Orientation control of functional molecules in Langmuir-Blodgett films caused by a trigger
molecule – infrared spectroscopic study on the orientation of n-alkane, trigger molecule
Langmuir 11, 4495-4498 (1995).
84. K. Ikegami, S. Kuroda, H. Tachibana, and M. Matsumoto
ESR study on Langmuir-Blodgett films of azobenzene-containing alkylpyridiniumtetracyanoquinodimethane 1:2 complexes
J. Phys. Soc. Jpn. 65, 237-245 (1996).
85. Y. Shimoi, S. Abe, S. Kuroda and K. Murata
Electronic structure and endor spectra of polarons in poly(p-phenylene vinylene)
Mol. Cryst. Liq. Cryst. 283, 237-242 (1996).
86. S. Kuroda, K. Murata and K. Ikegami
The stable radical in Langmuir-Blodgett films of a merocyanine dyeThin Solid Films 285, 615-617 (1996).
87. K. Ikegami, S. Kuroda, H. Tachibana, and M. Matsumoto
Changes in the ESR of the TCNQ columns caused by the photoisomerization of the azobenzene
group in the APT LB films
Thin Solid Films 285, 505-507 (1996).
88. K. Murata, S. Kuroda, Y. Shimoi, S. Abe, T. Ohnishi and T. Noguchi
Electron spin resonance of photogenerated polarons in poly(paraphenylen vinylene)
J. Phys. Soc. Jpn. 65, 3743-3746 (1996)

89. S. Kuroda, K. Murata, Y. Shimoi, S. Abe, T. Noguchi and T. Ohnishi
ENDOR spectra of polarons in poly(paraphenylene vinylene),
Synthetic Met. 84, 661-662 (1997).
90. K. Murata, S. Kuroda, Y. Shimoi, S. Abe, T. Noguchi and T. Ohnishi
ESR studies of photo-generated polarons in undoped poly(p-phenylene vinylene)/PPV
Synthetic Met. 84, 555-556 (1997).
91. Y. Shimoi, S. Abe, S. Kuroda and K. Murata
Electronic properties of neutral and polaron states in poly(p-phenylene vinylene)
Synthetic Met. 85, 1133-1134 (1997).
92. S. Kuroda, R. Azumi, M. Matsumoto, L.G. King and M.J. Crossley
Electron spin resonance of Cu-porhyrin of dimmer type in Langmuir-Blodgett films
Thin Solid Films 295, 92-94 (1997).
93. K. Murata, S. Kuroda, and K. Saito
Optical absorption spectra of mixed merocyanine dye Langmuir-Blodgett films
Thin Solid Films 295, 73-76 (1997).
94. K. Ikegami, S. Kuroda, H. Tachibana, and M. Matsumoto
Quasi-one-dimensional Hubbard system in Langmuir-Blodgett films of TCNQ complexes
Synthetic Met. 86, 2081-2082 (1997).
95. R. Azumi, M. Matsumoto, S. Kuroda and M.J. Crossley
Orientation control of porphyrin in the mixed monolayer at the air-water interface by adding
long-chain n-alkanes
Mol. Cryst. Liq. Cryst. 294, 469-472 (1997).
96. K. Murata, H. Shin, S. Kuroda and K. Saito
The mutual mixing effect in the LB films of merocyanine dyes
Mol. Cryst. Liq. Cryst. 294, 113-116 (1997).
97. K. Murata, S. Kuroda, Y. Shimoi, S. Abe, T. Noguchi and T. Ohnishi
Photon-energy dependence of light-induced ESR for poly(para-phenylene vinylene) and its
derivatives
Synthetic Met. 91, 359-362 (1997).
98. K. Murata, Y. Shimoi, S. Abe, S. Kuroda, T. Noguchi and T. Ohnishi
Photogenerated polarons in poly(paraphenylene vinylene)
Chem. Phys. 227, 191-201 (1998).
99. K. Murata, H. Shin, K. Saito and S. Kuroda
The formation of J-aggregates in mutual mixing merocyanine dyes LB films
Thin Solid Films 327, 446-449 (1998).
100. K. Ikegami, S. Kuroda, T. Nakamura, M. Matsumoto, S. Horiuchi, H. Yamochi, and G. Saito
Possible low-temperature phase transition of Langmuir-Blodgett films of a charge-transfer
complex detected by ESRThin Solid Films 327, 391-394 (1998).
101. S. Kuroda, Y. Shimoi, S. Abe, T. Noguchi and T. OhnishiElectron-nuclear double-resonance spectra of polarons in poly(paraphenyl-ne vinylene)
J. Phys. Soc. Jpn. 67, 3936-3944 (1998).
102. K. Marumoto, H. Tanaka, S. Kuroda, T. Manabe and M. Yamashita
Induced spin moments in quasi-one-dimensional halogen-bridged mixed metal complexes ofnickel and palladium
Phys. Rev. B 60, 7699-7702 (1999).
103. M. Yamashita, T. Ishii, H. Matsuzaka, T. Manabe, T. Kawashima, H. Okamoto, H. Kitagawa, T.
Mitani, K. Marumoto and S. Kuroda

Tuning of Charge Density Wave Strengths by Competition between Electron−Phonon
Interaction of PdII−PdIV Mixed-Valence States and Electron Correlation of NiIII States in
Quasi-One-Dimensional Bromo-Bridged Ni−Pd Mixed-Metal MX Chain Compounds
Ni 1-x Pd x (chxn) 2 Br 3
Inorg. Chem. 38, 5124-5130 (1999).
104. S. Kuroda, K. Marumoto, T. Manabe and M. Yamashita
ESR studies of halogen-bridged mixed-metal compounds Ni 1-x Pd x (chxn) 2 Br 3
Synthetic Met. 103, 2155-2156 (1999).
105. S. Kuroda, K. Marumoto, H. Ito, N. C. Greenham, R. H. Friend, Y. Shimoi and S. Abe
Spin distributions and excitation spectra of optically generated polarons in poly(pphenylenevinylene) derivatives
Chem. Phys. Lett. 325, 183-188 (2000).
106. K. Marumoto, H. Tanaka, S. Kozaki, S. Kuroda, S. Miya, T. Kawashima and M. Yamashita
ESR observation of averaged-valence and charge-density-wave states in quasi-one-dimensional
halogen-bridged binuclear metal complexes
Solid State Commun. 120, 101-106 (2001).
107. S. Kuroda, K. Marumoto, H. Kihara, H. Ofuchi, M. Tabuchi, Y. Takeda, A. G. Banshchikov, N.
S. Sokolov and N. L. Yakovlev
Electron Spin Resonance Study of Low-Dimensional Magnetic Properties of MnF 2 -CaF 2
Superlattices
Jpn. J. Appl. Phys. 40 Pt. 2, L1151-L1153 (2001).
108. T. Ishii, R. Kanehama, N. Aizawa, M. Yamashita, H. Matsuzaka, K. Sugiura, H. Miyasaka, T.
Kodama, K. Kikuchi, I. Ikemoto, H. Tanaka, K. Marumoto and S. Kuroda
Fullerene C 60 exhibiting a strong intermolecular interaction in a cocrystallinte with C 4
symmetrical cobalt tetrakis(di-tert-butylphenyl)porphyrin
Dalton Transactions 1, 2975-2980 (2001).
109. T. Manabe, T. Kawashima, T. Ishii, H. Matsuzaka, M. Yamashita, K. Marumoto, H. Tanaka, S.
Kuroda, H. Kitagawa, T. Mitani and H. Okamoto
Syntheses and physical properties of quasi-one-dimensional chloro-bridged Ni-Pd mixed-metal
MX-chain compounds, Ni1-xPdx(chxn) 2 Cl 3
Synthetic Met. 116, 415-418 (2001).
110. K. Marumoto, N. Takeuchi, S. Kuroda, R. Azumi and M. MatsumotoLight-induced ESR study of quinquethiophene (5T)
Synthetic Met. 119, 549-550 (2001).
111. S. Kuroda, K. Marumoto, N. C. Greenham, R. H. Friend, Y. Shimoi and S. Abe
ESR study of light-generated polarons in poly(p-phenylenevinylene) derivatives
Synthetic Met. 119, 655-656 (2001).
112. T. Manabe, T. Ishii, H. Matsuzaka, M. Yamashita, T. Kawashima, K. Marumoto, H. Tanaka, Y.
Itoh, S. Kuroda and H. Okamoto
Physical properties of halogen-bridged Ni-Pd mixed-metal complexes, Ni 1-x Pd x (chxn) 2 XY 2
Synthetic Met. 120, 925-926 (2001).
113. H. Tanaka, K. Marumoto, S. Kuroda, T. Manabe and M. Yamashita
ESR detection of induced moments Pd3+ in halogen-bridged Ni-Pd mixed-metal complexes
Synthetic Met. 120, 949-950 (2001).
114. S. Kuroda, K. Marumoto, Y. Shimoi and S. Abe
ESR spectroscopy of polarons in conjugated electroluminescent polymers
Thin Solid Films 393, 304-309 (2001).
115. Y. Hamanaka, H. Kurosawa, A. Nakamura, Y. Uchiyama, K. Marumoto and S. Kuroda
Femtosecond transient absorption study of merocyanine J-aggregates

J. Lumin. 94-95, 451-455 (2001).
116. S. Kuroda, K. Marumoto, H. Ito, N. C. Greenham, R. H. Friend, Y. Shimoi and S. Abe
ESR observation of optically-generated polarons in conjugated electroluminescent polymers
Mol. Cryst. Liq. Cryst. 371, 159-162 (2001).
117. S. Kuroda
Electron spin resonance characterization of Langmuir-Blodgett films containing functional LB
films
Colloids and Surf. A 198, 735-744 (2002).
118. M. Yamashita, K. Yokoyama, S. Furukawa, T. Manabe, T. Ono, K. Nakata, C. Kachi-Terajima,
F. Iwahori, T. Ishii, H. Miyasaka, K. Sugiura, H. Matsuzaki, H. Kishida, H. Okamoto, H.
Tanaka, Y. Hasegawa, K. Marumoto, H. Ito and S. Kuroda
Tuning of electronic structures of quasi-one-dimensional bromo-bridged Ni(III) complexes withstrong electron-correlation by doping of Co(III) ions, [Ni 1-x Co x (chxn) 2 Br]Br 2
Inorg. Chem. 41, 1998-2000 (2002).
119. H. Tanaka, K. Marumoto, S. Kuroda, T. Ishii, R. Kanehama, N. Aizawa, H. Matsuzaka, K.
Sugiura, H. Miyasaka, T. Kodama, K. Kikuchi, I. Ikemoto and M. Yamashita
Electron spin resonance studies of Co(tbp)・C 60 single crystal
J. Phys.: Condensed Matter 14, 3993-4000 (2002).
120. H. Tanaka, K. Marumoto, S. Kuroda, T. Manabe and M. Yamashita
ESR detection of induced spin moments in halogen-bridged mixed-metal complexes
Ni 1-x Pd x (chxn) 2 Br 3
J. Phys. Soc. Jpn. 71, 1370-1375 (2002).
121. K. Marumoto, N. Takeuchi, T. Ozaki and S. Kuroda
ESR studies of photogenerated polarons in regioregular poly(3-alkylthiophene)-fullerenecomposite
Synthetic Met. 129, 239-247 (2002).
122. Y. Hamanaka, H. Kurosawa, A. Nakamura, Y. Uchiyama, K. Marumoto and S. Kuroda
Exciton delocalization length of merocyanine J-aggregates in Langmuir-Blodgett films studied
from linear and nonlinear absorption measurements
Chem. Phys. Lett. 363, 233-240 (2002).
123. S. Kuroda, H. Ito, Y. Uchiyama, T. Mori, K. Marumoto and I. Hatta
J-Aggregate Formation of 6-Methyl-Merocyanine Dye in Mixed Langmuir-Blodgett Films with
Arachidic Acid in a Wide Range of Mixing Ratio
Jpn. J. Appl. Phys. 41 Pt. 1, 6223-6227 (2002).
124. T. Manabe, K. Yokoyama, T. Ishii, H. Miyasaka, H. Matsuzaka, M. Yamashita, T. Kawashima,
H. Matsuzaki, H. Kishida, H. Okamoto, K. Marumoto, H. Tanaka, H. Itoh and S. Kuroda
Physical properties of quasi-one-dimensional mixed-metal and mixed-halogen complexes,
Ni 1-x Pd x (chxn) 2 Cl y Br 1-y Y 2
Mol. Cryst. Liq. Cryst. 376, 165-170 (2002).
125. H. Ito, M. Sunata, S. Kuroda, T. Manabe and M. Yamashita
Electrical conduction of halogen-bridged metal complexes Ni 1-x Pd x (chxn) 2 Br 3
Mol. Cryst. Liq. Cryst. 379, 285-290 (2002).
126. K. Marumoto, K. Soda, S. Kuroda and Y. Moritomo
ESR Studies of Layered-Perovskite Manganites R 0.5 Sr 1.5 MnO 4 (R = La, Nd)
J. Phys. Soc. Jpn. 72, 582-587 (2003).
127. S. Kuroda
ESR and ENDOR studies of solitons and polarons in conjugated polymers
Appl. Magn. Reson. 23, 455-468 (2003)
128. R. Kanehama, H. Miyasaka, K. Sugiura, M. Yamashita, H. Ito, S. Kuroda, H. Kishida, H.

Okamoto
New charge-transfer salts (ET) 8 (MnIIBr 4 ) 2 (DCE) 2 and (ET) 3 MnIIBr 4 : Preparations, structuresand physical properties (ET = BEDT-TTF, DCE = 1,2-dichloroethane)
Synthetic Met. 135, 633-634 (2003).
129. M. Yamashita, H. Aso, S. Matsunaga, K. Takizawa, K. Nakata, C. Kachi-Terajima, F. Iwahori,
T. Ishii, H. Miyasaka, K. Sugiura, T. Kawashima, K. Takai, N. Kuroda, M. Shiro, H. Kishida, H.
Okamoto, H. Takahashi, H. Tanaka, K. Marumoto and S. Kuroda
Unprecedented Soliton Formation Mechanism in Quasi-One-Dimensional Chloro-Bridged
PtII-PtIV Mixed-Valence Compound, {[Pt(en) 2 ][PtCl 2 (en) 2 ]} 3 (CuCl 4 ) 4 ·12H 2 O
Chem. Lett. 32, 278-279 (2003).
130. H. Tanaka, K. Marumoto, S. Kuroda and M. Yamashita
LESR studies of long-lived photogenerated spins in the MX-chain complex, Pd(chxn) 2 Br 3
Synthetic Met. 135-136, 317-318 (2003).
131. T. Ono, M. Yamashita, K. Yokoyama, S. Furukawa, T. Manabe, K. Sugiura, T. Ishii, H.
Miyasaka, H. Matsuzaki, H. Kishida, H. Okamoto, K. Marumoto, H. Tanaka, Y. Hasegawa, S.
Kuroda and H. Ito
Tuning of spin density wave strength of Ni(III) complexes with strong electron-correlation
Synthetic Met. 135-136, 357-358 (2003).
132. K. Marumoto, Y. Muramatsu, N. Takeuchi and S. Kuroda
Light-induced ESR studies of polarons in regioregular poly(3-alkylthiophene)-fullerenecomposites
Synthetic Met. 135-136, 433-434 (2003).
133. M. Yamashita, T. Ono, S. Matsunaga, M. Sasaki, S. Takaishi, F. Iwahori, H. Miyasaka, K.
Sugiura, H. Kishida, H. Okamoto, H. Tanaka, Y. Hasegawa, K. Marumoto, H. Ito, S. Kuroda
and N. Kimura
Carrier Doping Effect into Quasi-One-Dimensional Bromo-Bridged Ni(III) Complexes with
Strong Electron-Correlation by Cu(II) ions, [Ni 1-x Cu x (chxn) 2 Br]Br 2-x
Inorg. Chem. 42, 7692-7694 (2003).
134. R. Kanehama, M. Umemiya, F. Iwahori, H. Miyasaka, K. Sugiura, M. Yamashita, Y. Yokochi,
H. ItoNovel ET-coordinated copper(I) complexes: Syntheses, structures, and physical properties (ET= BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene)
Inorg. Chem. 42, 7173-7181 (2003).
135. H. Tanaka, S. Kuroda, T. Yamashita, M. Mitsumi and K. Toriumi
ESR observations of valence ordering states and thermally excited solitons in MMX complexes
Pt 2 (RCS 2 ) 4 I (R = n-Butyl and n-Pentyl)
J. Phys. Soc. Jpn. 72, 2169-2172 (2003). (Letters)
136. H. Ito, Y. Hasegawa, H. Tanaka, S. Kuroda, M. Mitsumi and K. Toriumi
Uniaxial compression of the Halogen-bridged binuclear metal complex Pt 2 (n-ButylCS 2 ) 4 I
J. Phys. Soc. Jpn. 72, 2149-2152 (2003). (Letters)
137. K. Marumoto, N. Takeuchi and S. Kuroda
Nanoscale spatial extent of photogenerated polarons in regioregular poly(3-octylthiophene)
Chem. Phys. Lett. 382, 541-546 (2003).
138. K. Ikegami, and S. Kuroda
FT-IR studies of LB films a merocyanine dye
Chem. Phys. 295, 205-213 (2003).
139. K. Marumoto, Y. Muramatsu and S. Kuroda
Quadrimolecular recombination kinetics of photogenerated charge carriers in regioregularpoly(3-alkylthiophene)-fullerene composites
Appl. Phys. Lett. 84, 1317-1319 (2004).

140. M. Umemiya, H. Miyasaka, K. -i. Sugiura, M. Yamashita, H. Nishikawa, K. Kikuchi, I.
Ikemoto, Y. Yokochi, H. Ito, and S. Kuroda
New organic conductor (DMET) 2 CuCl 2 : synthesis, structure and physical properties
Journal de Physique IV France 114, 589 (2004).
141. S. Ukai, H. Ito and S. Kuroda
Mobility of charge carriers in regioregular poly(3-hexylthiophene) induced by field effecttransistor with Al 2 O 3 as gate insulator
Jpn. J. Appl. Phys. 43 366-371 (2004).
142. S. Kuroda
ESR and ENDOR spectroscopy of solitons and polarons in π-conjugated polymers
Trans. MRS-J 29, 965-970 (2004).
143. H. Ito, S. Ukai, N. Nomura, K. Hayashi, T. Ozaki, Y. Muramatsu, K. Marumoto and S. Kuroda
Charge carrier studies of regioregular polyalkylthiophene
Trans. MRS-J 29, 971-976 (2004).
144. K. Marumoto, Y. Muramatsu and S. Kuroda
Photogeneration and recombination kinetics
polymer-fullerene composites”,
Trans. MRS-J 29, 977-980 (2004).

ofchargedexcitationsinconducting

145. S. Takaishi, H. Miyasaka, K. Sugiura, M. Yamashita, H. Matsuzaki, H. Kishida, H. Okamoto,H. Tanaka, K. Marumoto, H. Ito, S. Kuroda and T. Takami
Visualization of local valence structures in quasi-one-dimensional halogen-bridged complexes[Ni 1-x Pd x (chxn) 2 Br]Br 2 by STM
Angew. Chem. Int. Ed. 43, 3171-3175 (2004).
146. K. Marumoto, Y. Muramatsu, S. Ukai, H. Ito and S. Kuroda
Electron spin resonance observations of field-induced polarons
poly(3-octylthiophene) metal-insulator-semiconductor diode structures
J. Phys. Soc. Jpn.. 73, 1673-1676 (2004). (Letter)inregioregular147. M. Yamashita, D. Kawakami, S. Matsunaga, Y. Nakayama, M. Sasaki, S. Takaishi, F. Iwahori,
H. Miyasaka, K. Sugiura, Y. Wada, H. Miyamae, H. Matsuzaki, H. Okamoto, H. Tanaka, K.
Marumoto and S. Kuroda
quasi-one-dimensional
halogen-bridged[{[Pt(en) 2 ][PtX 2 (en) 2 ]} 3 ][{(MX 5 )X 3 } 2 ]·12H 2 O:
PtII-PtIV mixed-valence compounds with magnetic counteranions
Angew. Chem. Int. Ed. 43, 4763-4767 (2004).
148. K. Marumoto, H. Takahashi, H. Tanaka, S. Kuroda, T. Ishii, R. Kanehama, N. Aizawa and M.
Yamashita
Electron spin resonance studies of silver complexes of octaethylporphyrin cocrystallized withfullerenes: observation of triplet spin states due to magnetic dipolar interactions
J. Phys.: Condensed Matter 16, 8753-8762 (2004).
149. S. Kuroda
J-aggregation and its characterization in Langmuir-Blodgett films of merocyanine dyes
Advances in Colloid and Interface Science 111, 181-209 (2004).
150. H. Ito, H. Tamura, S. Kuroda, and H. Yamochi
Structural and transport studies of BEDO-TTF-arachidic-acid conducting Langmuir-Blodgett
filmsTrans. MRS-J, 30, 131-134 (2005).
151. H. Ito, Y. Yokochi, H. Tanaka, S. Kuroda, R. Kanehama, M. Umemiya, H. Miyasaka, K-I.
Sugiura, M. Yamashita, H. Tajima, J. Yamaura
Charge carriers in divalent BEDT-TTF conductor (BEDT-TTF)Cu 2 Br 4
Phys. Rev. B. 71, 085202 1-7 (2005).

152. Y. Hamanaka, O. Kawasaki, H. Kurasawa, T. Yamauchi, Y. Mizutani, S. Kuroda, and A.
Nakamura
Hierarchical structure of merocyanine J-aggregates
Colloids and Surf. A 257-58, 105-109 (2005).
153. H. Ito, H. Tamura, S. Kuroda, H. Yamochi, and G. Saito
Electrical conduction of BEDO-TTF-arachidic-acid Langmuir-Blodgett Films
Colloids and Surf. A 257-58, 37-40 (2005).
154. H. Ito, D. Suzuki, Y. Yokochi, S. Kuroda, M. Umemiya, H. Miyasaka, K-I. Sugiura, M.
Yamashita, and H. Tajima
Quasi-one-dimensional electronic structure of (DMET)CuCl 2
Phys. Rev. B. 71, 212503-1-4 (2005).
155. M. Mitsumi, H. Goto, S. Umebayashi, Y. Ozawa, M. Kobayashi, T. Yokoyama, H. Tanaka, S.
Kuroda, K. Toriumi
A neutral mixed-valent conducting polymer formed by electron transfer between metal d andligand π orbitals
Angew. Chem. Int. Ed. 44, 4164-4168 (2005).
156. K. Marumoto, Y. Muramatsu, S. Ukai, H. Ito and S. Kuroda
ESR observations of electric-field-induced polarons in regioregular poly(3- alkylthiophene)s in
MIS diode structures
Synthetic Met. 154, 45-48 (2005).
157. K. Marumoto, T. Sakamoto, Y. Muramatsu and S. Kuroda
Quadrimolecular recombination kinetics of photogenerated positive polarons and C 60 - radical
anions in regioregular poly(3-alkylthiophene)-C 60 composites measured by light-induced ESR
Synthetic Met. 154, 85-88 (2005).
158. H. Ito, Y. Yokochi, H. Tanaka, S. Kuroda, R. Kanehama, M. Umemiya, H. Miyasaka, K. -i.
Sugiura, M. Yamashita
Electrical conduction in divalent BEDT-TTF salts
Synthetic Met. 153, 441-444 (2005).
159. H. Tanaka, Y. Hasegawa, H. Ito, S. Kuroda, T. Yamashita, M. Mitsumi, and K. Toriumi
Control of the electronic phase transition of the MMX-chain complex Pt 2 (n-pentylCS 2 ) 4 I withthe uniaxial compression
Synthetic Met. 152, 141-144 (2005).
160. K. Marumoto, Y. Muramatsu, Y. Nagano, T. Iwata, S. Ukai, H. Ito, S. Kuroda, Y. Shimoi and S.
AbeElectron spin resonance of field-induced polarons in regioregular poly(3-alkylthiophene) using
metal-insulator-semiconductor diode structures
J. Phys. Soc. Jpn. 74, 3066-3076 (2005).
161. S. Ukai, H. Ito, K. Marumoto and S. Kuroda
Electrical conduction of regioregular and regiorandom poly(3-hexylthiophene) doped withiodineJ. Phys. Soc. Jpn. 74, 3314-3319 (2005).
162. H. Ito, M. Hanada, H. Tanaka, S. Kuroda, M. Mitsumi, K. Toriumi
Conduction anisotropy of the halogen-bridged metal complex Pt 2 (n-butylCS 2 ) 4 I
J. Phys. Soc. Jpn. 74, 3334-3339 (2005).
163. S. Ukai, S. Igarashi, M. Nakajima, K. Marumoto, H. Ito, S. Kuroda, K. Nishimura, Y. Enomoto
and G. Saito
Molecular-fastener effects on transport property of TTC n -TTF field-effect transistors
Colloids and Surf. A 284-285, 589-593 (2006).
164. H. Ito, N. Nomura, T. Suzuki, S. Ukai, K. Marumoto and S. Kuroda

Photocurrent of thin-film cells of regioregular polyalkylthiophene-C 60 composites
Colloids and Surf. A 284-285, 613-616 (2006).
165. K. Marumoto, Y. Nagano, T. Sakamoto, S. Ukai, H. Ito and S. Kuroda
ESR studies of field-induced polarons in MIS diode structures with self-organized regioregularpoly(3-hexylthiophene)
Colloids and Surf. A 284-285, 617-622 (2006).
166. H. Tanaka, T. Mizutani, S. Kuroda
Control of formation and molecular orientation of J-aggregates in Langmuir–Blodgett films of
mixed merocyanine dyes
Colloids and Surf. A 284-285, 97-102 (2006).
167. A. Nakamura, Y. Mizutani, N. Okuyama, Y. Hamanaka, S. Kuroda
Formation of J-aggregates of mixed merocyanine dyes in Langmuir-Blodgett films
Colloids and Surf. A 284-285, 89-92 (2006).
168. H. Ito, Y. Yokochi, D. Suzuki, H. Tanaka, S. Kuroda, K. Enomoto, S. Uji, M. Umemiya, H.
Miyasaka, K. -i. Sugiura, and M. Yamashita
Field-induced SDW phase and superconductivity of (DMET) 2 CuCl 2
Synthetic Met. 156, 162-165 (2006).
169. M. Umemiya, M. Goto, N. Kobayashi, S. Takaishi, T. Kajiwara, M. Yamashita, H. Miyasaka,K.-i Sugiura, H. Watanabe, D. Suzuki, H. Ito, S. Kuroda
New charge transfer salts based on unsymmetrical donor DMET and metal complex anions:(DMET) 3 [Cr(isoq) 2 (NCS) 4 ] and (DMET) 3 [Cr(phen)(NCS) 4 ]CH 3 CN
Chem. Lett. 35, 368-369 (2006).
170. H. Tanaka, S. Kuroda, T. Yamashita, M. Mitsumi, and K. Toriumi
ESR studies of the spin dynamics in quasi-one-dimensional iodo-bridged diplatinum complex
Pt 2 (n-pentylCS 2 ) 4 I
Phys. Rev. B 73, 245102 (2006).
171. S. Takaishi, D. Kawakami, M. Yamashita, M. Sasaki, T. Kajiwara, H. Miyasaka, K. Sugiura, Y.
Wakabayashi, H. Sawa, H. Matsuzaki, H. Kishida, H. Okamoto, H. Watanabe, H. Tanaka, K.
Marumoto, H. Ito and S. Kuroda
Dynamical valence fluctuation at the charge-density-wave phase boundary in iodide-bridged Pt
compound [Pt(chxn) 2 I]I 2
J. Am. Chem. Soc. 128, 6420-6425 (2006).
172. K. Marumoto, S. Kuroda, T. Takenobu and Y. Iwasa
Spatial Extent of Wave Functions of Gate-Induced Hole Carriers in Pentacene Field-EffectDevices as Investigated by Electron Spin ResonancePhys. Rev. Lett. 97, 256603-1-256603-4 (2006).
173. S. Kuroda, K. Marumoto, T. Sakanaka, N. Takeuchi, Y. Shimoi, S. Abe, H. Kokubo, T.
Yamamoto
Electron-nuclear double-resonance observation of spatial extent of polarons in polythiophene
and poly(3-alkylthiophene)
Chem. Phys. Lett. 435, 273-277 (2007).
174. H. Tanaka, N. Hasegawa, T. Sakamoto, K. Marumoto and S. Kuroda
Light-induced ESR studies of quadrimolecular recombination kinetics of photogenerated charge
carriers in regioregular poly(3-alkylthiophene)-C 60 composites –alkyl chain dependence
Jpn. J. Appl. Phys. 46, 5187-5192 (2007).
175. S. Watanabe, K. Ito, H. Tanaka, H. Ito, K. Marumoto and S. Kuroda
Electron spin resonance observation of gate-induced charge carriers in organic field-effectdevices fabricated on silicon substrates
Jpn. J. Appl. Phys. 46, L792-L795 (2007).

176. H. Ito, D. Suzuki, H. Watanabe, H. Tanaka, S. Kuroda, M. Umemiya, N. Kobayashi, M. Goto,
K. Sugiura, H. Miyasaka, S. Takaishi, T. Kajiwara, M. Yamashita, E. Ohmichi, T. Osada
Metal-insulator transition of charge transfer salts based on unsymmetrical donor DMET andmetal halide anions, (DMET) 4 (MCl 4 )(TCE) 2 (M = Mn, Co, Cu, Zn; TCE =1,1,2-trichloroethane)
J. Am. Chem. Soc., 129, 8510-8519 (2007).
177. K. Marumoto, T. Sakamoto, S. Watanabe, H. Ito, and S. Kuroda
Electron spin resonance observation of gate-induced ambipolar charge carriers in organic
devices
Jpn. J. Appl. Phys. 46, L1191-L1193 (2007).
178. H. Ito, Y. Niimi, A. Suzuki, K. Marumoto and S. Kuroda
Photocurrent of regioregular poly(3-alkylthiophene)-fullerene composites in surface-type
photocells
Thin Solid Films 516, 2743-2746 (2008).
179. S. Takaishi, M. Yamashita, H. Matsuzaki, H. Okamoto, H. Tanaka, S. Kuroda, A. Goto, T.
Shimizu, T. Takenobu, and Y. Iwasa
complexes[Ni(S,S-bn) 2 Br]Br 2
One-dimensional
bromo-bridged
NiIII(S,S-bn=2S,3S-diaminobutane):synthesis, physical properties, and electrostatic carrier doping
Chem. Eur. J. 14, 472-477 (2008).
180. J. Xie, H. Wu, D. Kawakami, H. Iguchi, S. Takaishi, M. Yamashita, H. Matsuzaki, H. Okamoto,H. Tanaka, and S. Kuroda
Electronic structure of CoIII doped bromo-bridged Ni complexes, [Ni 1-x Co x (chxn) 2 Br]Br 2
Inorg. Chem. 47, 1949-1952 (2008).
181. H. Tanaka, H. Nishiyama, S. Kuroda, T. Yamashita, M. Mitsumi, and K. Toriumi
ESR observations of optically generated solitons in the quasi-one-dimensional iodo-bridged
diplatinum complex Pt 2 (n-pentylCS 2 ) 4 I
Phys. Rev. B 78, 033104 (1-4) (2008).
182. S. Takaishi, M. Takamura, T. Kajiwara, H. Miyasaka, M. Yamashita, M. Iwata, H. Matsuzaki,
H. Okamoto, H. Tanaka, S. Kuroda, H. Nishikawa, H. Oshio, K. Kato, M. Takata
Charge-density-wave to Mott-Hubbard phase transition in quasi-one-dimensional
bromo-bridged Pd compounds
J. Am. Chem. Soc. 130, 12080-12084 (2008).
183. H. Ito, T. Ishihara, H. Tanaka, S. Kuroda, T. Suzuki, S. Onari, Y. Tanaka, J. Yamada, K.
KikuchiRoles of spin fluctuation and frustration in the superconductivity of β -(BDA-TTP) 2 X (X=SbF 6 ,AsF 6 ) under uniaxial compression
Phys. Rev. B 78, 172506 (1-4) (2008).
184. M. Sasaki, H. Wu, D. Kawakami, S. Takaishi, T. Kajiwara, H. Miyasaka, B. K. Breedlove, M.
Yamashita, H. Kishida, H. Matsuzaki, H. Okamoto, H. Tanaka, and S. Kuroda
Effect of an In-Plane Ligand on the Electronic Structures of Bromo-Bridged Nano-Wire Ni-Pd
Mixed-Metal Complexes, [Ni 1-x Pd x (bn) 2 Br]Br 2 (bn = 2S,3S-Diaminobutane)
Inorg. Chem. 48, 7446-7451 (2009).
185. S. Watanabe, H. Tanaka, H. Ito, K, Marumoto, S. Kuroda
ESR studies of ambipolar charge charriers in metal-insulator-semiconductor diodes ofregioregular poly(3-hexylthiophene)- PCBM composites
Synth. Met. 159, 893-896 (2009).
186. S. Kuroda, S. Watanabe, K. Ito, H. Tanaka, H. Ito, and K. Marumoto
Electron spin resonance of charge carriers in organic field-effect devices
Appl. Magn. Reson. 36, 357-370 (2009).
187. H. Tanaka, S. Watanabe, H. Ito, K. Marumoto, and S. Kuroda

Direct observation of the charge carrier concentration in organic field-effect transistors byelectron spin resonanceAppl. Phys. Lett. 94, 103308 (1-3) (2009).
188. K. Marumoto, M. Kato, H. Kondo, S. Kuroda, N.C. Greenham, R.H. Friend, Y. Shimoi, S. Abe
Electron spin resonance and electron nuclear double resonance of photogenerated polarons inpolyfluorene and its fullerene composite
Phys. Rev. B 79, 245204 (1-11) (2009).
189. H. Iguchi, S. Takaishi, H. Miyasaka, M. Yamashita, H. Matsuzaki, H. Okamoto, H. Tanaka,
and S. Kuroda
Water-vapor-induced reversible switching of electronic states in an MMX-Type chain complex
with retention of single crystallinity
Angew. Chem. Int. Ed. 49, 552-555 (2010).
190. S. Watanabe, H. Tanaka, S. Kuroda, A. Toda, S. Nagano, T. Seki, A. Kimoto, J. Abe
Electron spin resonance observation of field-induced charge carriers in ultrathin-film transistorsof regioregular poly(3-hexylthiophene) with controlled in-plane chain orientation
Appl. Phys. Lett. 96, 173302-1-3 (2010).
191. H. Tanaka, Y. Yokoi, N. Hasegawa, S. Kuroda, T. Iijima, T. Sato, T. Yamamoto
Quadrimolecular recombination kinetics of photogenerated charge carriers in the composites ofregioregular polythiophene derivatives and soluble fullerenes
J. Appl. Phys. 107, 083708-1-9 (2010).
192. K. Marumoto, N. Arai, H. Goto, M. Kijima, K. Murakami, Y. Tominari, J. Takeya, Y. Shimoi,
H. Tanaka, S. Kuroda, T. Kaji, T. Nishikawa, T. Takenobu and Y. Iwasa
Microscopic mechanisms behind the high mobility in rubrene single-crystal transistors as
revealed by field-induced electron spin resonancePhys. Rev. B 83, 075302-1-075302-6 (2011).
193. S. Watanabe, H. Tanaka, H. Ito, S. Kuroda, T. Mori, K. Marumoto and Y. Shimoi
Direct determination of interfacial molecular orientations in field-effect devices of
P3HT/PCBM composites by electron spin resonanceOrg. Electron. 12, 716-723 (2011).
194. M. Tsuji, N. Arai, K. Marumoto, J. Takeya, Y. Shimoi, H. Tanaka, S. Kuroda, T. Takenobu, Y.
Iwasa
Electron spin resonance study of interface trap states and charge carrier concentration in rubrene
single-crystal field-effect transistors
Appl. Phys. Express 4, 085702-1-3 (2011).
195. H. Tanaka, M. Kozuka, S. Watanabe, H. Ito, Y. Shimoi, K. Takimiya, S. Kuroda
Observation of field-induced charge carriers in high-mobility organic transistors of athienothiophene-based small molecule: Electron spin resonance measurements
Phys. Rev. B 84, 081306-1-4 (R) (2011).
196. H. Ito, Y. Nishikawa, J. Suzuki, A. Suzuki, S. Watanabe, H. Tanaka, H. Kishida, A. Nakamura,
S. Kuroda
Quadrimolecular recombination of persistent photocarriers in surface-type photocells ofregioregular poly(3-hexylthiophene)/methanofullerene composites
Jpn. J. Appl. Phys. 50, 091602-1-4 (2011).
197. S. Watanabe, H. Tanaka, S. Kuroda, A. Toda, H. Tomikawa, S. Nagano, and T. Seki
Charge transport anisotropy due to interfacial molecular orientation in polymeric transistors
with controlled in-plane chain orientation
Appl. Phys. Express 5, 021602-1-3 (2012).
198. H. Tanaka, S. Kuroda, H. Iguchi, S. Takaishi, and M. Yamashita
Electron spin resonance observation of dehydration-induced
quasi-one-dimensional iodo-bridged diplatinum complexes

spin

excitationsinPhys. Rev. B 85, 073104-1-5 (2012).
199. Y. Shimoi, K. Marumoto, and S. Kuroda
Theoretical ESR g Values in Rubrene and Oligoacenes: Implication to Molecular Orientation at
Interfaces in Organic FETs
Mol. Cryst. Liq. Cryst. 566, 33-37 (2012).
200. Y. Ando, H. Ito, S. Watanabe, and S. Kuroda
Variable-range hopping conduction in ion-gel-gated electrochemical transistors of regioregularpoly(3-hexylthiophene)
J. Phys. Soc. Jpn. 81, 114721 (2012).
201. H. Tanaka, M. Hirate, S. Watanabe, K. Kaneko, K. Marumoto, T. Takenobu, Y. Iwasa, and S.
KurodaElectron spin resonance observation of charge carrier concentration in organic field-effecttransistors during device operation
Phys. Rev. B, 87, 045309-1-7 (2013).
202. L. Pilia, E. Sessini, F. Artizzu, M. Yamashita, A. Serpe, K. Kubo, H. Ito, H. Tanaka, S. Kuroda,
J. Yamada, P. Deplano, C. J. Gómez-García, and M. L. Mercuri
New BDH-TTP/[MIII(C 5 O 5 ) 3 ]3− (M = Fe, Ga) Isostructural Molecular Metals
Inorg. Chem. 52, 423-430 (2013).
203. H. Ito, T. Iwata, S. Watanabe and S. Kuroda
Balanced ambipolar transport of the composite film of a carbazole-benzothiadiazole copolymer
with a fullerene derivative
Appl. Phys. Express 6, 051601-1-3 (2013).
204. H. Ito, T. Tokai, J. Suzuki, H. Tanaka and S. Kuroda
Photocarrier recombination of polymer/fullerene composites in surface-type photocells
Jpn. J. Appl. Phys. 53, 01AB09-1-4 (2014).
205. H. Tanaka. M. Hirate, S. Watanabe, and S. Kuroda
Microscopic signature of metallic state in semicrystalline conjugated polymers doped withfluoroalkylsilane molecules
Adv. Mater. 26, 2376–2383 (2014).
206. Y. Kinoshita, H. Tanaka, Y. Shimoi, K. Takimiya and S. Kuroda
Low-temperature carrier dynamics in high-mobility organic transistors of alkylated
dinaphtho-thienothiophene as investigated by electron spin resonanceAppl. Phys. Lett. 105, 033301-1-5 (2014).
207. S. Kumagai, S. Takaishi, B. K. Breedlove, H. Okamoto, H. Tanaka, S. Kuroda, and M.
Yamashita
Bromide-bridged palladium(III) chain complexes showing charge bistability near room
temperature
Chem. Commun. 50, 8382-8384 (2014).
208. T. Harada, H. Ito, Y. Ando, S. Watanabe, H. Tanaka and S. Kuroda
Signature of the insulator–metal transition of a semicrystalline conjugated polymer inionic-liquid-gated transistors
Appl. Phys. Express 8, 021601-1-4 (2015).
209. H. Tanaka, E. Sawada, K. Azuma, and S. Kuroda
Direct probing of gate-bias stress effect in organic transistors by electron spin resonancespectroscopy
Appl. Phys. Express 8, 051603-1-4 (2015).
210. H. Tanaka, S. Nishio, H. Ito, and S. Kuroda
Microscopic signature of insulator-to-metal transition in highly-doped semicrystalline
conducting polymers in ionic-liquid-gated transistors
Appl. Phys. Lett. 107, 243302-1-5 (2015).
211. H. Ito, T. Harada, H. Tanaka, and S. Kuroda
Critical regime for the insulator-metal transition in highly-ordered conjugated polymers gatedwith ionic liquidJpn. J. Appl. Phys. 55 03DC08 1-5 (2016).
212. T. Yoshida, S. Takaishi, H. Iguchi, H. Okamoto, H. Tanaka, S. Kuroda, Y. Hosomi, S. Yoshida,
H. Shigekawa, T. Kojima, H. Ohtsu, M. Kawano, B. K. Breedlove, L. Gué rin, and M.
Yamashita
Optically visible phase separation between Mott-Hubbard and charge-density-wave domains ina Pd-Br chain complex
ChemistrySelect 2, 259 –263 (2016).
213. K. Kang, S. Watanabe, K. Broch, A. Sepe, A. Brown, I. Nasrallah, M. Nikolka, Z. Fei, M.
Heeney, D. Matsumoto, K. Marumoto, H. Tanaka, S. Kuroda, and H. Sirringhaus
Two-dimensional coherent charge transport in highly ordered conducting polymers doped bysolid state diffusion
Nature Mater. 15, 896-902 (2016).
214. T. Sakanoue, J. Li, H. Tanaka, R. Ito, S. Ono, S. Kuroda, and T. Takenobu
High current injection into dynamic p–n homojunction in polymer light-emitting
electrochemical cells
Adv. Mater. 29, 1606392-1-7 (2017).
215. M. R. Mian, H. Iguchi, S. Takaishi, H. Murasugi, T. Miyamoto, H. Okamoto, H. Tanaka, S. Kuroda,
B. K. Breedlove, M. Yamashita
Multiple-hydrogen-bond approach to uncommon Pd(III) oxidation state: A Pd-Br chain withhigh conductivity and thermal stability
J. Am. Chem. Soc. 139, 6562-6565 (2017).
216. S. Kawamura, A. Wakamatsu, S. Kuroda, T. Takenobu, H. Tanaka
Microscopic observation of highly mobile charge carriers in organic transistors ofsemicrystalline conducting polymers
Jpn. J. Appl. Phys. 57, 02CA04-1-4 (2018).
217. S. Kumagai, S. Takaishi, H. Iguchi, B. K. Breedlove, T. Kaneko, H. Ito, S. Kuroda, M.
Yamashita
Correlation between chemical and physical pressures on charge bistability in[Pd(en) 2 Br](Suc-C n ) 2 ·H 2 O
Inorg. Chem. 57, 12–15 (2018).

Reviews
1.

S. Kuroda, M. Motokawa, M. Date
Submillimiter ESR and SH3 Term
BUTSURI, 32, 933-935 (1977). (in Japanese)2.

S. Kuroda, K. Ikegami, M. Sugi
Sturucture and Properties of Langmuir-Blodgett Films
BUTSURI, 43, 921-928 (1988). (in Japanese)

3.

S. Kuroda
Shape of solitons in polyacetylene observed by ENDORKAGAKU TO KOGYO, 46, 628-630 (1993). (in Japanese)

4.

S. Kuroda
Shapes of Solitons and Polarons in Conjugated Polymers
BUTSURI, 51, 273-279 (1996). (in Japanese)5.

S. Kuroda
Structure and Functions of Organic Molecular Materials II（Polymeric Systems）
OYO BUTSURI, 76, 795-798 (2007). (in Japanese)

6.

K.Marumoto, S. Kuroda
Transport mechanism and magnetism of charge carriers at the interface of organic FETs
BUTSURI, 62, 851-855 (2007). (in Japanese)Book (Edited)
1. "Materials and Measurements in Molecular Electronics" （K. Kajimura, S. Kuroda, Eds.）
Springer Proceedings in Physics, Vol.81 (Springer, Tokyo, 1996).

Book (Chapters)
1.

K. Mizoguchi and S. Kuroda,"Magnetic properties" in Handbook of Organic Conductive Molecules and Polymers, Vol. 3,(Ed. H.S. Nalwa) (John Wiley & Sons, Chichester, 1997) Chap. 6.

2.

S. Kuroda"Electron spin resonance spectroscopy of Langmuir-Blodgett films containing functional
molecules" in Organized Monolayers and Assemblies: Structure, Processes and Function,
Studies in Interface Science 16 (Eds. D. Mobius and R. Miller) (Elsevier, Amsterdam, 2002)
Chap. 6.

3.

K. Marumoto and S. Kuroda“Polarons in conjugated polymer and its composite with fullerene”, in Nanotechnology andNano-Interface Controlled Electronic Devices, (Eds. M. Iwamoto, K. Kaneto and S. Mashiko)(Elsevier, Amsterdam, 2003) Chap. 20.

4.

S. Kuroda and K. Marumoto, "Electron Spin Resonance of Organic Devices" in Encyclopediaof Nanoscience and Nanotechnology (second edition) (Ed. H. S. Nalwa) (American Scientific
Publishers, California, 2011) Vol. 13, 481-496.