Name: 7th Workshop on Nanotube Optics and Nanospectroscopy (WONTON 2018)
Start: 2018-07-08T18:00:00+09:00
End: 2018-07-12T14:30:00+09:00
Location: The Prince Hakone Lake Ashinoko

7th Workshop on Nanotube Optics and Nanospectroscopy (WONTON 2018)

from Sunday 8 July 2018 (18:00) to Thursday 12 July 2018 (14:30)

Monday 2 July 2018
Tuesday 3 July 2018
Wednesday 4 July 2018
Thursday 5 July 2018
Friday 6 July 2018
Saturday 7 July 2018
Sunday 8 July 2018

18:00 Welcome Reception & Registration
Welcome Reception & Registration
18:00 - 20:00

Monday 9 July 2018
09:00 Optics and Photonics of Aligned Carbon Nanotube Films - Junichiro Kono (Rice University)
Optics and Photonics of Aligned Carbon Nanotube Films
- Junichiro Kono (Rice University)
09:00 - 09:30
09:30 Mid- and high-temperature exciton photophysics of carbon nanotubes and their applications - Yuhei Miyauchi
Mid- and high-temperature exciton photophysics of carbon nanotubes and their applications
- Yuhei Miyauchi
09:30 - 10:00
10:00 Tunable Interlayer Excitons in Folded & Twisted Graphene - Matt Graham (Oregon State University, Physics)
Tunable Interlayer Excitons in Folded & Twisted Graphene
- Matt Graham (Oregon State University, Physics)
10:00 - 10:20
10:20 Coffee Break
Coffee Break
10:20 - 10:40
10:40 Trions at a Trapping Defect - YuHuang Wang (University of Maryland)
Trions at a Trapping Defect
- YuHuang Wang (University of Maryland)
10:40 - 11:10
11:10 Molecular design for photoluminescence modulation of locally functionalized single-walled carbon nanotubes - Tomohiro Shiraki (Kyushu University)
Molecular design for photoluminescence modulation of locally functionalized single-walled carbon nanotubes
- Tomohiro Shiraki (Kyushu University)
11:10 - 11:40
11:40 Nonperturbing, conjugation-preserving covalent functionalization of single-walled carbon nanotubes - Antonio Setaro (Freie Universität Berlin)
Nonperturbing, conjugation-preserving covalent functionalization of single-walled carbon nanotubes
- Antonio Setaro (Freie Universität Berlin)
11:40 - 12:00
The most common outcome of covalent treatments of carbon nanotubes is the conversion of sp2 carbon atoms into their sp3 hybridization state. Even mild approaches interrupt the conjugation of the carbon network with detrimental effects on their optoelectronic properties. Cycloaddition reactions establish covalent bonds through pi-electrons to bridge targeted functionalities onto the tubes. The carbon atoms below the bridge are converted into the sp3 state (closed configuration, Fig. 1a) or, if the C-C bond below the bridge is released, keep their sp2 character (open configuration, Fig. 1b) and preserve the overall conjugation of the extended network. We have recently demonstrated that the outcome of a triazine-based [2+1] cycloaddition reaction results in the open configuration (Fig. 1c) and preserves the intrinsic properties of the tubes, even at high degrees of functionalization (4%) [1]. Here we will highlight some of the benefits of this approach, such as the preservation of their radiative emission (Fig. 1d) or the fine-tuning of the position of their Fermi levels. We will moreover discuss how the functionalized tubes can be exploited as starting platform for advanced materials. We show how the attachment of molecular systems makes them integrating part and in electronic communication with the conjugated network of the tubes, yielding new ways to non-perturbatively tailor, control, and alter the optical response of the tubes for novel applications. The conjugation of the molecular switch spyropiran-merocyanine, for example, enables controlled on-off switching of the tubes’ emission to be exploited for nanotubes-based super-resolution microscopy. [1] A. Setaro, *et al.*, Nat. Comm. **8**, 14281 (2017).
12:00 Lunch
Lunch
12:00 - 13:30
14:00 Electroluminescence from carbon nanotubes - Ralph Krupke (Karlsruhe Institute of Technology and Technische Universitat Darmstadt)
Electroluminescence from carbon nanotubes
- Ralph Krupke (Karlsruhe Institute of Technology and Technische Universitat Darmstadt)
14:00 - 14:30
Electrically generated light emission from carbon nanotubes is of great interest for the development of nanoscale on-chip electro-optical transducers and single-photon sources [1,2], operating in the telecom band and at GHz frequency [3]. To further advance device performance, reproducibility and reliability we need to better understand and control the mechanism of light generation, tailor the interface between the nanotube and environment and to locally modify nanotube properties with nanoscale precision. In my presentation I will report on our current efforts in this direction and present latest results.
14:30 Electrochemically doped light-emitting devices of transition metal dichalcogenide monolayers - Taishi Takenobu (Nagoya University)
Electrochemically doped light-emitting devices of transition metal dichalcogenide monolayers
- Taishi Takenobu (Nagoya University)
14:30 - 15:00
15:00 Probing exciton-exciton annihilation in hBN with cathodoluminescence experiments - Alexandre Plaud (ONERA-CNRS / UVSQ-CNRS)
Probing exciton-exciton annihilation in hBN with cathodoluminescence experiments
- Alexandre Plaud (ONERA-CNRS / UVSQ-CNRS)
15:00 - 15:20
15:20 Coffee Break
Coffee Break
15:20 - 15:40
15:40 Bright and tunable single-photon emission with a carbon nanotube embedded in a fiber micro-cavity. - Christophe Voisin (Ecole Normale Supérieure, Paris)
Bright and tunable single-photon emission with a carbon nanotube embedded in a fiber micro-cavity.
- Christophe Voisin (Ecole Normale Supérieure, Paris)
15:40 - 16:10
16:10 Spectroscopy of localized excitons in cryogenic carbon nanotubes - Alexander Hoegele (LMU Munich)
Spectroscopy of localized excitons in cryogenic carbon nanotubes
- Alexander Hoegele (LMU Munich)
16:10 - 16:40
16:40 Room-temperature single photon emission from carbon nanotubes - Akihiro Ishii (RIKEN)
Room-temperature single photon emission from carbon nanotubes
- Akihiro Ishii (RIKEN)
16:40 - 17:00
Single-walled carbon nanotubes are a promising material as quantum light sources at room temperature and as nanoscale light sources for integrated photonic circuits on silicon. Here we discuss the use of carbon nanotubes as room-temperature single photon emitters from two different approaches. The first is where efficient exciton-exciton annihilation process [1] is used to reduce the number of mobile excitons. We investigate photon statistics in as-grown individual air-suspended carbon nanotubes and perform theoretical analysis to show that diffusion-driven annihilation of mobile excitons can produce high-purity single photons [2]. In the second approach where exciton trapping sites are created to localize excitons [3], we demonstrate integration of carbon nanotube dopant states to silicon photonic crystal microcavities [4]. The coupling of the dopant emission to the microcavity results in an increase of photoluminescence by a factor of ~100, corresponding to a single-photon emission rate of 1.7 x 10^7 Hz which is the highest reported for room-temperature operation of nanotube single photon sources. Our results show that both diffusive (1D) and localized (0D) excitons in carbon nanotubes can produce high quality single photons at room temperature, opening up a pathway to quantum light sources with additional functionality and flexibility. Work supported by JSPS (KAKENHI JP16H05962, JP16K13613, JP17H07359) and MEXT (Photon Frontier Network Program, Nanotechnology Platform). A.I. acknowledges support from MERIT, and H.M. is supported by RIKEN Junior Research Associate Program. We thank Advanced Manufacturing Support Team at RIKEN for their assistance in machining. This work was conducted in part at the Center for Integrated Nanotechnologies, a US Department of Energy, Office of Science user facility and supported in part by Los Alamos National Laboratory Directed Research and Development funds.
17:00 1
1
17:00 - 19:00
Contributions

17:00 Cryogenic spectroscopy of sp3 defect states in carbon nanotubes - Manuel Nutz (Ludwig-Maximilians-University Munich)

17:15 High-Speed and integrated graphene blackbody emitters - Yusuke Fukazawa

17:30 Photon antibunching in single-walled carbon nanotubes at telecommunication wavelengths and room temperature - Rintaro Kawabe (Hideyuki Maki Group in Keio University (Department of Applied Physics and Physico-Informatics,Faculty of Science and Technology)

17:45 Cavity-control of bright and dark interlayer excitons in van der Waals heterostructures - Michael Förg (Ludwig-Maximilians-Universität Munich)

18:00 Evaluation of substituent effects on the potential levels of locally-functionalized single-walled carbon nanotubes using in situ photoluminescence spectroelectrochemistry - Tomonari Shiraishi (Kyushu University)

18:15 Optical properties of core-shell systems based on carbon nanotubes - Lucile Orcin-Chaix

18:30 Kinetics of diazonium functionalization of carbon nanotubes - Kerstin Müller (Julius Maximilian University Würzburg, Germany)

18:45 Enhanced Raman scattering of graphene using double resonance in silicon photonic crystal nanocavities - Widianta Gomulya (Nanoscale Quantum Photonics Laboratory, RIKEN)

18:45 Tracing individual growth process of single-walled carbon nanotubes by digitally coding isotope labels - Keigo Otsuka (The University of Tokyo)

18:45 Modulation-Doped Multiple Quantum Wells of Aligned Single-Wall Carbon Nanotubes - Natsumi Komatsu (Rice University)

18:45 Photophysical properties of porphyrin–single-walled carbon nanotube linked systems with various spacer lengths - Tomokazu Umeyama (Kyoto University)

18:45 Thin films from carbon nanotubes of highly tuned structure and properties - Dawid Janas (Department of Chemistry, Silesian University of Technology, B. Krzywoustego 4, 44-100, Gliwice, Poland)

18:45 Monolayer WSe2-MoS2 Lateral Heterojunction Light-Emitting Diodes - Jiang Pu (Nagoya University)

18:45 Optical Properties of Oxidized Single-Wall Carbon Nanotubes - Mari Ohfuchi (Fujitsu Labs.)

18:45 Effect of functionalization and subsequent thermal treatment on photoluminescence properties of single-walled carbon nanotubes - Yutaka Maeda (Department of Chemistry, Tokyo Gakugei University)
19:00 Dinner
Dinner
19:00 - 20:30
Tuesday 10 July 2018
09:00 Luttinger liquid in carbon nanotubes - Feng Wang (University of California, Berkeley)
Luttinger liquid in carbon nanotubes
- Feng Wang (University of California, Berkeley)
09:00 - 09:30
Single Walled carbon nanotubes provide the ideal platform to explore Luttinger liquid physics due to the strong one-dimensional quantum confinement. I will discuss out combined electrical and optical studies to correlate the unusual electron tunneling and plasmon excitations of a Luttinger liquid. I will also show that distinctly different plasmon behavior in electrically gated metallic and semiconducting carbon nanotubes, which are described by the linear Luttinger liquid and nonlinear Luttinger liquid, respectively.
09:30 Single SWNT spectroscopy for nano-metrology - Yoshikazu Homma (Department of Physics, Tokyo University of Science)
Single SWNT spectroscopy for nano-metrology
- Yoshikazu Homma (Department of Physics, Tokyo University of Science)
09:30 - 10:00
10:00 Conservation law of angular momentum in Raman spectroscopy using circularly polarized light - Riichiro Saito (Tohoku University)
Conservation law of angular momentum in Raman spectroscopy using circularly polarized light
- Riichiro Saito (Tohoku University)
10:00 - 10:20
10:20 Coffee Break
Coffee Break
10:20 - 10:40
10:40 Exciton-Polaritons, Plexcitons and Trion-Polaritons in Single-Walled Carbon Nanotube Thin Films and Devices - Jana Zaumseil (Heidelberg University)
Exciton-Polaritons, Plexcitons and Trion-Polaritons in Single-Walled Carbon Nanotube Thin Films and Devices
- Jana Zaumseil (Heidelberg University)
10:40 - 11:10
11:10 Excitons in Coupled Nanotube Photovoltaic Thin Films - Michael Arnold
Excitons in Coupled Nanotube Photovoltaic Thin Films
- Michael Arnold
11:10 - 11:40
We have previously reported on the efficient harvesting of excitons from photoexcited, semiconducting nanotube thin films. The films are interfaced with C60 fullerenes to form a type-II heterojunction with band offsets that exceed the exciton binding energy. Excitons photogenerated near the heterointerface are dissociated into separable electrons (which transfer to C60) and holes (which remain on the nanotubes) with quantum efficiency ≈ 90%. This behavior has promise for creating nanotube photoabsorber-based photovoltaic solar cells and photodetectors. However, the efficiency by which excitons can be dissociated remains high only when the nanotube films are thin (5 nm in thickness). The efficiency rapidly decreases as the nanotube film thickness increases, due to poor inter-nanotube exciton migration. Here, we present on recent work designed to understand and improve exciton migration in coupled nanotube films via theory [1] and experiments [2-4]. We have calculated exciton transfer rates due to Coulomb coupling between nanotubes of varying orientations considering both first- and second-order (phonon-assisted) processes. Second-order dark-to-bright inter-nanotube transfer is as fast as both first and second order bright-to-bright transfer. This important result shows that dark excitonic states are able to efficiently and directly transfer between nanotubes in films.[1] We have tested the hypothesis that poor inter-nanotube exciton migration in films can be attributed to quenching by defects via experiments in which (i) diazonium defects are intentionally added to nanotubes at known concentrations [2] and in which (ii) nanotubes are prepared via three different processes of decreasing harshness: extended ultrasonication, brief ultrasonication, and shear force mixing [3]. Inter-nanotube exciton transfer is then characterized via photoluminescence-, transient absorption-, and device photocurrent spectroscopies. Our results show that poor out-of-plane exciton diffusion depth can be attributed in large part due to losses that arise from the trapping and quenching of excitons by defects induced during processing. Other photovoltaic parameters including fill-factor and open-circuit voltage also improve with decreasing processing harshness. [1] A.H. Davoody, M.S. Arnold, I. Knezevic et al., J. Phys. Chem. C, 121, 13084−13091 (2017). [2] J. Wang, J.T. Flach, M.T. Zanni, M.S. Arnold et al., J. Phys. Chem. C, 4, 8310-8318 (2017). [3] M.J. Shea, J.T. Flach, M.T. Zanni, M.S. Arnold et al., In Revision (2018).
11:40 Theory of a carbon-nanotube polarization switch - Ken-ichi Sasaki (NTT Basic Research Laboratories)
Theory of a carbon-nanotube polarization switch
- Ken-ichi Sasaki (NTT Basic Research Laboratories)
11:40 - 12:00
12:00 Lunch
Lunch
12:00 - 13:30

13:30 Free Discussion
Free Discussion
13:30 - 19:00

19:00 Dinner
Dinner
19:00 - 20:30
Wednesday 11 July 2018
09:00 Transition metal dichalcogenide nanotubes - Yoshi Iwasa (The University of Tokyo & RIKEN)
Transition metal dichalcogenide nanotubes
- Yoshi Iwasa (The University of Tokyo & RIKEN)
09:00 - 09:30
Due to their favorable and rich electronic and optical properties, group-VI-B transition-metal dichalcogenides (TMDs) have attracted considerable interest. They have earned their position in the materials portfolio of the spintronics and valleytronics communities. The electrical performance of TMDs will be enhanced by rolling up the two-dimensional (2D) sheets to form quasi-one-dimensional (1D) tubular structures. Actually, the TMD nanotubes were first synthesized back in 1992 [1], but only recently device related researches have been conducted [2].In this presentation, we discuss transport and optoelectronic properties ranging from field effect transistor (FET) operation to solar cell actions in tungsten disulfide multiwalled nanotubes (WS2-NT). We first fabricated electric double layer transistor (EDLT) of an individual WS2-NT and found an ambipolar operation, in sharp contrast to the solid gated FET devices which exhibits only n-type conduction. Furthermore, we found that gating with KClO4/polyethylene glycol electrolyte, induce superconductivity at Tc = 5.8 K. This is the first superconductivity in the individual nanotube structure. Importantly, this superconductivity of gated WS2 exhibited peculiar transport properties arising only from tublar and chiral structure [3]. Using the EDLT devices, we were able to fabricate a p-n junction in an individual WS2-NT, and found that this p-n junction shows current-driven light emission, and photovoltaic actions. Both of these actions are linearly polarized along the NT axis, and more importantly, the external quantum efficiency for the photovoltaic effect reaches a value as high as 4.8%, exceeding by far that of 2D TMDs and even approaching the internal quantum efficiency of the 2D TMDs [4]. [1] R. Tenne et al., Nature 360, 444 (1992). [2] R. Levi et al., Nano Lett. 13, 3736 (2013). [3] F. Qin et al., Nat. Comm. 8, 14465 (2017). [4] Y. J. Zhang et al., 2D Materials, in press.
09:30 Stacking-dependent Interlayer Couplings in 2D Materials - Liu Kaihui (Peking University)
Stacking-dependent Interlayer Couplings in 2D Materials
- Liu Kaihui (Peking University)
09:30 - 10:00
10:00 Controlling the optical fingerprint of transition metal dichalcogenides via molecules, strain and disorder - Maja Feierabend (Chalmers )
Controlling the optical fingerprint of transition metal dichalcogenides via molecules, strain and disorder
- Maja Feierabend (Chalmers )
10:00 - 10:20
10:20 Coffee Break
Coffee Break
10:20 - 10:40
10:40 Carbon Nanotube Optical Bandgap Modulation for Cancer Research and Diagnosis - Daniel Heller (Memorial Sloan Kettering Cancer Center)
Carbon Nanotube Optical Bandgap Modulation for Cancer Research and Diagnosis
- Daniel Heller (Memorial Sloan Kettering Cancer Center)
10:40 - 11:10
The measurement of biomarkers, drugs, and metabolites in live cells and organisms would allow for improvements in disease detection, drug development, and biomedical research. Single-walled carbon nanotubes have suitable optical properties for application as sensors for use in live cells and in vivo, including narrow, near-infrared emission bands with sensitivity to the local environment. To develop them into sensors for bioanalytes, we devised new methods to probe single-walled carbon nanotube optical properties, including near-infrared hyperspectral imaging and live-tissue excitation/emission spectroscopy. We also identified a new mechanism of carbon nanotube photoluminescence environmental responsivity, whereby electrostatic charges mediate spectral red-shifting. We believe that this effect is consistent with previous findings of carbon nanotube solvatochromic behavior. We found that this mechanism facilitates the measurement of multiple classes of bioanaltytes, such as nucleic acids, drugs, and proteins, enabling the development of in vivo implantable sensors for the study and detection of cancer.
11:10 Probing the optical dipole transition and vibrational coherences in individual (5,4) carbon nanotubes by femtosecond pulse shaping - Richard Ciesielski (Ludwig-Maximilians-Universität München)
Probing the optical dipole transition and vibrational coherences in individual (5,4) carbon nanotubes by femtosecond pulse shaping
- Richard Ciesielski (Ludwig-Maximilians-Universität München)
11:10 - 11:30
11:30 H<sub>2</sub>-evolving SWCNT Photocatalysts for Effective Use of Solar Energy - Yutaka Takaguchi (Okayama University)
H<sub>2</sub>-evolving SWCNT Photocatalysts for Effective Use of Solar Energy
- Yutaka Takaguchi (Okayama University)
11:30 - 11:50
12:00 Lunch
Lunch
12:00 - 13:30
14:00 Killer defects in semiconducting SWNTs - Tobias Hertel (Institute of Physical and Theoretical Chemistry)
Killer defects in semiconducting SWNTs
- Tobias Hertel (Institute of Physical and Theoretical Chemistry)
14:00 - 14:30
The doping of semiconductors is key for providing electronic and photonic devices with their desired functionality. This comes with the realization, that the failure to successfully dope certain classes of materials “is an important bottleneck for the technological utilization of these materials” in electronic or photonic devices, as succinctly expressed by Zunger [1]. This concern also pertains to the doping of semiconducting single-wall carbon nanotubes (s-SWNTs) where our ability to provide stable and measured concentrations of surplus carriers remains a major challenge. Current approaches to doping of s-SWNTs are mostly designed around redox chemistry or covalent modification with electron pulling or pushing side-chain functionalities while the use of substitutional impurities has hardly been explored for the purpose of electronic enhancement. Despite the importance of doping for device technologies, however, it appears that our ability to quantify the concentration of impurity site concentrations or their effectiveness in providing surplus free carriers is still rather limited. To address these shortcomings we have performed spectroscopic investigations of redox-and electrochemically doped (6,5) s-SWNT samples using fluorescence and absorption spectroscopy [2]. Spectroscopically, there appears to be no noticeable difference between these two approaches. In both cases, exciton bands are found to broaden, become asymmetric and shift to higher energies when the electrochemical potential is shifted toward valence or conduction band edges. These observations are consistent with confinement of excitons by a stochastic distribution of impurities, suggesting that doping is in-homogeneous rather than homogeneous. Moreover, our analysis suggests that the interaction of minority carriers with external counterions can provide deep traps in the band gap which act as ‘killer defects’, capturing free charge carriers and effectively preventing the desired homogenous doping. We also discuss how the analysis of exciton absorption bands can be applied to quantify impurity level concentrations. In the context of optical spectroscopy this allows to define and clearly distinguish between intrinsic-, weak-, moderate- and heavy-doping regimes. The onset of degenerate s-SWNT doping is determined to be at about ± 0.1 e/nm. The observed generation of deep charge traps by adsorbed counterions can largely be attributed to weak dielectric screening of Coulomb interactions by SWNTs or their environment, a common characteristic of low-dimensional systems. We take this as evidence for serious fundamental challenges which may have far reaching and possibly broader implications for the successful fabrication of functional semiconductor devices from nanoscale materials. 1. A. Zunger, Appl. Phys. Lett 83, 57-59 (2003). 2. K. Eckstein, H. Hartleb, M.M. Achsnich, F. Schöppler, T. Hertel, ACS Nano 11, 10401 (2017).
14:30 Nanoscale Imaging in, of & with Luminescent Single Walled Carbon Nanotubes - Laurent Cognet (University of Bordeaux)
Nanoscale Imaging in, of & with Luminescent Single Walled Carbon Nanotubes
- Laurent Cognet (University of Bordeaux)
14:30 - 15:00
15:00 Antenna-Controlled Antibunching in the Photoluminescence of Single Carbon Nanotubes - Achim Hartschuh (LMU Munich)
Antenna-Controlled Antibunching in the Photoluminescence of Single Carbon Nanotubes
- Achim Hartschuh (LMU Munich)
15:00 - 15:20
15:20 Coffee Break
Coffee Break
15:20 - 15:40
15:40 Optical properties of dyes confined into carbon and boron nitride nanotubes - Etienne Gaufres (CNRS)
Optical properties of dyes confined into carbon and boron nitride nanotubes
- Etienne Gaufres (CNRS)
15:40 - 16:10
The inner cavity of nanotubes has been used as a template for the encapsulation of elongated dyes molecules, such as polythiophenes (6T). The 1D confinement of the nanotube wall drives the stacking of the molecules and induces original aggregation effects in their optical properties [1,2]. When confined inside a carbon nanotube, the organics dyes exhibit for instance a surprisingly strong Raman signal clear of its luminescence emission due to an efficiently quenching effect from the nanotube [3]. Here we show that boron nitride nanotubes (Eg~5 eV) having inner diameters between 1 nm to 5 nm provide similar 1D confinement effects with the difference that they preserve the luminescence of the dyes. The resulting 1D nanohybrids (dye@BNNT) shows in photoluminescence imaging experiments strong and tunable luminescence emissions depending on the dyes used. Experiments on individual dyes@BNNT demonstrate that the BNNT protect the dyes against oxidation and reduce significantly the dyes photobleaching under continuous photo-excitation. Preliminary results on Daphnia Pulex colored with dyes@BNNT suggest that these dye@BNNT nanoprobes have reduced toxicity for multimodal imaging based on Raman and luminescence and that they can be adapted to work in the NIR I window to study biological materials. (1) E. Gaufrès et al Nature Photon. (2014) (2) S. Cambré et al Nature Nano (2015) (3) E. Gaufrès et al ACS Nano (2016)
16:10 Diameter-dependent optical absorption and energy transfer from encapsulated dye molecules to single wall carbon nanotubes - Sofie Cambré (University of Antwerp)
Diameter-dependent optical absorption and energy transfer from encapsulated dye molecules to single wall carbon nanotubes
- Sofie Cambré (University of Antwerp)
16:10 - 16:40
16:40 Synthesis and properties of single-walled carbon nanotubes co-axially wrapped with mono- and few-layer BN nanotubes - Shigeo Maruyama (The University of Tokyo)
Synthesis and properties of single-walled carbon nanotubes co-axially wrapped with mono- and few-layer BN nanotubes
- Shigeo Maruyama (The University of Tokyo)
16:40 - 17:00
17:00 Poster Session 2
Poster Session 2
17:00 - 19:00
Contributions

17:00 Spectral tuning of optical coupling between air-mode nanobeam cavities and individual carbon nanotubes - Hidenori Machiya (Nanoscale Quantum Photonics Laboratory, RIKEN)

17:15 Environmental electrometry with luminescent carbon nanotubes - Jonathan Noe (Ludwig-Maximilian University Munich)

17:30 Photocurrent Spectroscopy of Dye Sensitized Carbon Nanotubes - Benjamin Flavel (Karlsruhe Institute of Technology)

17:45 Post modification approach for photoluminescence modulation of locally functionalized single-walled carbon nanotubes - Tamehito Shiga (Kyushu University)

18:00 Molecular screening effects on trion binding energies and electronic band gaps in air-suspended carbon nanotubes - Shunsuke Tanaka (Quantum Optoelectronics Research Team, RIKEN Center for Advanced Photonics)

18:15 Narrow-band thermal exciton radiation in individual suspended single-walled carbon nanotubes - Taishi Nishihara (Nagoya University)

18:30 Reflectance of Carbon Nanotube Forest metamaterials - Hiroshi Furuta (School of Systems Engineering, Kochi University of Technology)

18:45 Long-lived direct and indirect interlayer excitons in van der Waals heterostructures - Ursula Wurstbauer

18:45 Achieving 20% Efficiency Perovskite Solar Cells with High Stability by using Semiconducting Single-walled Carbon Nanotube Grain Bridges - Il Jeon (The University of Tokyo)

18:45 Phonon Assigning of G-band from Suspended Single-walled Carbon Nanotubes - Yuichiro Tanaka (Department of Physics, Tokyo University of Science)

18:45 Probing the optical dipole transition and vibrational coherences in individual (5,4) carbon nanotubes by femtosecond pulse shaping - Richard Ciesielski (Ludwig-Maximilians-Universität München)

18:45 Dielectric properties of vertically aligned carbon nanotubes in the mid-IR and THz spectral range - Hartmut Roskos (Physics Institute, Goethe-University )

18:45 Effects of Chirality and Defect Introduction on the Intermediate Frequency Mode - Takumi Inaba (Tokyo University of Science)

18:45 Photoluminescence from Single-walled Carbon Nanotubes on hexagonal Boron Nitride Substrates - Shohei Chiashi (The University of Tokyo)

18:45 Resonance Raman Signature of Intertube Excitons in Compositionally-Defined Carbon Nanotube Bundles - Jeffrey R. Simpson (Towson University and National Institute of Standards & Technology)
19:00 Dinner
Dinner
19:00 - 20:30
Thursday 12 July 2018
09:00 Photo-induced interactions between SWCNTs and oxygen - R. Bruce Weisman (Rice University)
Photo-induced interactions between SWCNTs and oxygen
- R. Bruce Weisman (Rice University)
09:00 - 09:30
09:30 Environmental Effects on Photoluminescence Properties of Carbon Nanotube sp3 Defects - Stephen Doorn
Environmental Effects on Photoluminescence Properties of Carbon Nanotube sp3 Defects
- Stephen Doorn
09:30 - 10:00
10:00 Direct Determination of Chemically Induced Doping Concentrations in (6,5)- Single-Wall Carbon Nanotubes by EPR - Andreas Sperlich (Julius Maximilian University of Würzburg, Germany)
Direct Determination of Chemically Induced Doping Concentrations in (6,5)- Single-Wall Carbon Nanotubes by EPR
- Andreas Sperlich (Julius Maximilian University of Würzburg, Germany)
10:00 - 10:20
Control over doping of semiconducting Single-Wall Carbon Nanotubes (SWNTs) by (electro-) chemical methods and intrinsic impurities are considered to be crucial for future applications of SWNTs in carbon-based electronics and photonics. Previous indirect all-optical techniques hypothesize charge carrier localization in semiconducting (6,5)-SWNTs following redox chemical AuCl3 doping, which is indicated by spectral and dynamical changes of the S1 exciton band [1]. Here, we present direct quantitative investigations of chemical impurities by means of electron paramagnetic resonance (EPR). For the as-produced (6,5)-SWNT samples we detected very low signal intensities stemming from two separate radical-like, isolated spin contributions that we assign to defects or residual impurities and which may be associated with what is sometimes referred to as intrinsic p-doping. Their concentration indicates exceptional nanotube quality with only few paramagnetic species per µm nanotube. Upon addition of the doping agent (AuCl3)2 we observe a linear increase of the EPR signal intensity which we ascribe to localized p-type impurities on the nanotube. However, at higher doping concentrations, the observed signal saturates, before decreasing again and finally vanishing at the highest AuCl3 concentrations. This seemingly puzzling result can be understood in terms of the formation of EPR silent, diamagnetic bi-radicals which start to appear at moderate doping concentrations. We model this behaviour with a stochastic formation of impurity sites in a 1D lattice, yielding good agreement with experimental data. In conclusion, we can confirm charge carrier confinement at low impurity concentrations in SWNTs with potentially far reaching implications for future device applications.
10:20 Coffee Break
Coffee Break
10:20 - 10:40
10:40 Long-lived Charge Separation Across Interfaces with Semiconducting Single-walled Carbon Nanotubes - Jeffrey Blackburn (National Renewable Energy Laboratory)
Long-lived Charge Separation Across Interfaces with Semiconducting Single-walled Carbon Nanotubes
- Jeffrey Blackburn (National Renewable Energy Laboratory)
10:40 - 11:10
Semiconducting single-walled carbon nanotubes (s-SWCNTs) are attractive absorbers for use in solar energy harvesting schemes because of their strong and energetically tunable optical absorption, and high charge carrier mobilities due to the delocalized nature of the π-electron system. Beyond their technological potential, s-SWCNTs offer attractive properties for fundamental studies of charge generation in strongly confined nanoscale systems and photoinduced electron transfer (PET) processes. For example, strong quantum confinement and low dielectric screening impart single-walled carbon nanotubes with exciton-binding energies substantially exceeding kBT at room temperature. Additionally, the energetically narrow and distinct spectroscopic signatures for excitons and charges within s-SWCNT thin films enables the unambiguous temporal tracking of fundamental photophysical processes occuring at important photoactive heterojunctions designed for charge separation. In this presentation, I will discuss recent studies that probe the generation and recombination of long-lived charges in samples consisting of heterojunctions between s-SWCNTs and various electron acceptors, both organic and inorganic. I will focus on the roles of important interfacial properties that can influence the kinetics and efficiency of the interfacial PET process and recombination of the resulting separated charges. These properties include the energetic energetic driving force for exciton dissociation, the amount of residual wrapping polymer on the highly enriched s-SWCNTs, the local dielectric enrivonrment, the presence or absence of an electric field, and geometrical factors of the interface that can be modified via structural properties of the acceptors. Better fundamental understanding of these model interfaces can inform the design of more efficient solar energy harvesting systems, photodetectors, and other opto-electronic devices.
11:10 PL quantum yield of SWCNTs: photon reabsorption effect - Hiromichi Kataura (NMRI, AIST)
PL quantum yield of SWCNTs: photon reabsorption effect
- Hiromichi Kataura (NMRI, AIST)
11:10 - 11:40
12:00 Lunch
Lunch
12:00 - 13:30

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