title: Neutron Radiation Tolerance of Two Benchmark Thiophene-Based Conjugated Polymers: the Importance of Crystallinity for Organic Avionics.
abstract: Aviation and space applications can benefit significantly from lightweight organic electronics, now spanning from displays to logics, because of the vital importance of minimising payload (size and mass). It is thus crucial to assess the damage caused to such materials by cosmic rays and neutrons, which pose a variety of hazards through atomic displacements following neutron-nucleus collisions. Here we report the first study of the neutron radiation tolerance of two poly(thiophene)s-based organic semiconductors: poly(3-hexylthiophene-2,5-diyl), P3HT, and the liquid-crystalline poly(2,5-bis (3-tetradecylthiophen-2-yl)thieno[3,2-b]thiophene), PBTTT. We combine spectroscopic investigations with characterisation of intrinsic charge mobility to show that PBTTT exhibits significantly higher tolerance than P3HT. We explain this in terms of a superior chemical, structural and conformational stability of PBTTT, which can be ascribed to its higher crystallinity, in turn induced by a combination of molecular design features. Our approach can be used to develop design strategies for better neutron radiation-tolerant materials, thus paving the way for organic semiconductors to enter avionics and space applications.
authors.affiliation: London Centre for Nanotechnology, Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK.
authors.forename: G M
authors.initials: GM
authors.lastname: Paternò
authors.affiliation: London Centre for Nanotechnology, Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK.
authors.forename: V
authors.initials: V
authors.lastname: Robbiano
authors.affiliation: London Centre for Nanotechnology, Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK.
authors.forename: K J
authors.initials: KJ
authors.lastname: Fraser
authors.affiliation: ISIS Pulsed Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot OX11 0QX, UK.
authors.forename: C
authors.initials: C
authors.lastname: Frost
authors.affiliation: ISIS Pulsed Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot OX11 0QX, UK.
authors.forename: V
authors.initials: V
authors.lastname: García Sakai
authors.affiliation: London Centre for Nanotechnology, Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK.
authors.forename: F
authors.initials: F
authors.lastname: Cacialli