title: Vacuum-deposited planar heterojunction polymer solar cells.
abstract: The vacuum thermal evaporation of poly(3-hexylthiophene) (P3HT) for application in photovoltaic cells is demonstrated. Structural changes before and after evaporation are determined using GPC, UV-vis absorption spectroscopy, NMR, and FTIR. GPC showed that the polymer molecular weight is reduced during evaporation, leading to a blue-shift of the absorption spectra. FTIR and NMR were used to examine the change in chemical structure: it was found that conjugation remains mostly intact; however, the conjugation length decreases and side chains dissociate from the backbone. Bilayer heterojunction solar cells were fabricated by sequential deposition of P3HT and C₆₀ and the photovoltaic response measured.
authors.affiliation: Department of Materials, University of Oxford, Parks Road, OX1 3PH Oxford, United Kingdom. peter.kovacik@materials.ox.ac.uk
authors.forename: Peter
authors.initials: P
authors.lastname: Kovacik
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Sforazzini
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Cook
authors.forename: Shawn M
authors.initials: SM
authors.lastname: Willis
authors.forename: Patrick S
authors.initials: PS
authors.lastname: Grant
authors.forename: Hazel E
authors.initials: HE
authors.lastname: Assender
authors.forename: Andrew A R
authors.initials: AA
authors.lastname: Watt
mesh_terms: D009930:Organic Chemicals; D010777:Photochemistry; D012993:Solar Energy; D013876:Thiophenes / Q000737:chemistry*; D014618:Vacuum
chemical_list: D009930:Organic Chemicals; D013876:Thiophenes; C507295:poly(3-hexylthiophene)