4:00pm - 4:30pmInvited
Controlling Charge Transport Physics from Hopping to Band-Like through Molecular Design
Institut National de la Recherche Scientifique (INRS), Canada
In disordered molecular systems such as organic semiconductors, the so-called band-like transport takes place when charge carriers are delocalized over more than a single molecular unit and it is associated with an increase in carrier mobility upon temperature decrease. Hitherto, the relationship between such type of transport and molecular design is not fully understood.
During my talk I will tackle this issue by comparing an interesting set of experiments carried out on two different yet very similar dicyanoperylenecarboxydiimide derivatives (PDI) molecules bearing either fluorinated (PDIF-CN2) or alkylated (PDI8-CN2) lateral chains. The former derivative would exhibit band-like transport whilst hopping transport was identified as the main charge transport mechanism for the latter molecular system. Both molecules were exposed to a comparable degree of extrinsic disorder that is considered to stem from undesired coupling to polar phonons at the interface with the dielectric . Hence, this study allows for the first time to focus only on intrinsic disorder, originated by thermal lattice fluctuations, as the key element which allows to enter the band-like regime.
A comparative study that includes multiple characterization techniques such as inelastic neutron scattering, THz, UPS and EELS spectroscopy, GIWAXS, low-T electrical characterization and solid-state NMR but also modeling and simulations allow us to unravel the origin of band-like transport mechanism by looking at the molecular fluctuations and their effect on the phonon modes of both compounds.
 N. A. Minder, S. Ono, Z. Chen, A. Facchetti, A. F. Morpurgo, Adv. Mater. 2012, 24, 503.
4:30pm - 5:00pmInvited
Stretchable Polymeric Microelectrode Arrays for Electrophysiological Recording and Stimulation
Nanyang Technological University, Singapore
Development of fully-polymeric microelectroe arrays (MEAs) employing conducting polymers as pristine conductors is an important intermediate step in the growth of the next generation bio-integrated electronics, as theycan have the potential to provide a new route for achieving flexible and stretchable bioelectronics, and to benefit the fabrication of more cost-effective, intimate and conformal biotic/abiotic interfaces. However, the research on fully-polymeric MEAs is still in its embryonic stage, leaving many critical challenges (such as the low conductivity, complicated and unreliable fabrication processes, and strechability) to be resolved in order to meet the practical demands. Here, I will present our latest development in the fabrication of a fully-polymeric microelectrode array concurrent with high conductivity (exceeding 800 S/cm), excellent stretchability and low impedance by combining an optimized electropolymerization, corrugated conductor structure via “stamping transfer method”. Through these as-prepared devices, we demonstrated a successful implementation of using fully-polymeric MEAs for in-vivo pathological application by conformally recording the electrocorticograph signals from a rat in normal and epileptic state respectively. Further, these MEAs were also successful in stimulating the ischiadic nerve of the rat.
5:00pm - 5:30pmInvited
Morphology Control of Polycrystalline Films by Precursor Approach
Nara Institute of Science and Technology, Japan
Control of grain size and morphology of small molecular polycrystalline film is critical for the improvement of charge carrier mobility of organic semiconductor devices. We have investigated “precursor approach”, in which a well-soluble precursor compound is solution-deposited then quantitatively converted in-situ to a target semiconductor film with releasing leaving groups by thermal annealing or photoirradiation . The morphology of semiconductor crystalline-film can be controlled by deposition condition, such as solvents for spin coating and concentration of precursors, annealing temperature and photoirradiation conditions for the conversion reaction, post annealing temperature, and so on. The structures of leaving groups and substituents on the molecules also affect the crystalline growth process. In this presentation, molecular design of acenes and tetrabenzoporphyrin derivatives for organic field-effect transistors and organic photovoltaics and morphology control of the films by the precursor approach will be focused [2,3,4].
 M. Suzuki, T. Aotake, Y. Yamaguchi, N. Noguchi, H. Nakano, K. Nakayama, H. Yamada, J. Photochem. Photobiol. C, 2014, 18, 50 (Review).
 Y. Yamaguchi, M. Suzuki, T. Motoyama, S. Sugii, C. Katagiri, K. Takahira, S. Ikeda, H. Yamada, K. Nakayama, Sci. Rep., 2014, 4, 7151.
 Y. Tamura, D. Kuzuhara, M. Suzuki, H. Hayashi, N. Aratani, H. Yamada, J. Mater. Chem. A, 2016, 4, 15333.
 H. Saeki, M. Misaki, D. Kuzuhara, H. Yamada, Y. Ueda, Jpn. J. Appl. Phys. 2013, 52, 111601.
5:30pm - 6:00pmInvited
Merging Heavy Main Group Elements with Conjugated Frameworks for Luminescence Applications
University of Alberta, Canada
In this presentation we will show how our early work on preparing polytellurophenes1led to the discovery of tellurium-containing heterocycles that are phosphorescent in air,2 a desirable property for OLEDs. Moreover we will describe recent efforts to synthesis π-extended tellurophene frameworks in order to achieve improved charge carrier properties and color tunable phosphorescence.
 (a) He, G.; Kang, L.; Torres Delgado, W.; Shynkaruk, O.; Ferguson, M. J.; McDonald, R.; Rivard, E. J. Am. Chem. Soc. 2013, 135, 5360.
 (a) He, G.; Torres Delgado, W.; Schatz, D. J.; Merten, C.; Mohammadpour, A.; Mayr, L.; Ferguson, M. J.; Brown, A.; Shankar, K.; Rivard, E. Angew. Chem., Int. Ed. 2014, 53, 4587. (b) He, G.; Wiltshire, B. D.; Choi, P.; Savin, A.; Sun, S.; Mohammadpour, A.; Ferguson, M. J.; McDonald, R.; Farsinezhad, S.; Brown, A.; Shankar, K.; Rivard, E. Chem. Commun. 2015, 51, 5444. (c) Parke, S. M.; Boone, M. P.; Rivard, E. Chem. Commun. 2016, 52, 9485.
6:00pm - 6:15pmOral
Designing and Fabrication of Electrochromic Pixels Displays Using Di-Isopropylbenzyl Derivative Of Poly (3,4-Propylenedioxythiophene)
1Birla Institute of Technology and Science, India; 2Indian Institute of Science, Bangalore, India
An electrochromic (EC) pixel display was designed and fabricated by using a novel monomer di-4-isopropyl benzyl substituted (3,4-propylenedioxythiophene) (ProDOT-IPBz2). This (ProDOT-IPBz2) monomer was electrochemically polymerized on ITO coated glass, using cyclic voltammetry at a scan rate of 100 mVs−1. This PProDOT-IPBz2thin film was studied for the optical and electrochemical characterization under reduction and oxidation states and also quantified the colour contrast and colour efficiency to estimate its applicability as EC pixel display. The polymer film showed dark purple color, with intense absorption which was uniform between 450 and 650 nm at fully reduced state. The absorption peak narrowed down slightly towards longer wavelength region (850–900 nm) at the oxidation states. The PProDOT-IPBz2 film showed a color contrast of about 48% with faster response time of 1 s. The coloration efficiency (CE) value for the thin film was calculated as ~305 cm2C−1, which is more significant for EC device applications. Thus characterized polymer thin film was used to fabricate a EC pixel display of 2X2 pixel array on a patterned ITO coated glass. Patterns on ITO coated glass was achieved by wet etching method. The optical color contrast of the EC pixel display was calculated to be 40% at 600 nm, the response time of EC pixel for bleaching and coloration was about 2 s and 2.5 s respectively. The coloration efficiency of EC pixel was found to be 555 cm2C−1 at 600 nm in the fully doped state. This EC pixel was successfully switched for more than 1000 cycles without much failure in color contrast (<5% T). The EC pixel displays showed transmissive, magenta and violet colored states at applied potentials of 1.5 V,−1.0 V and −2.0 V respectively. This EC display proved as an efficient display as faster response time and better colour contrast, and can be used for various applications.