title: Structure-property relationships of small bandgap conjugated polymers for solar cells.
abstract: Conjugated polymers as electron donors in solar cells based on donor/acceptor combinations are of great interest, partly due to the possibility of converting solar light with a low materials budget. Six small bandgap polymers with optical bandgap ranging from 1.0-1.9 eV are presented in this paper. All polymers utilize an electron donor-acceptor-donor (DAD) segment in the polymer backbone, creating a partial charge-transfer, to decrease the bandgap. The design, synthesis and the optical characteristics as well as the solar cell characteristics of the polymers are discussed. The positions of the energy levels of the conjugated polymer relative to the electron acceptor are of significant importance and determine not only the driving force for exciton dissociation but also the maximum open-circuit voltage. This work also focuses on investigating the redox behavior of the described conjugated polymers and electron acceptors using square wave voltammetry. Comparing the electrochemical data gives important information of the structure-property relationships of the polymers.
authors.affiliation: Department of Chemical and Biological Engineering, Polymer Technology, Chalmers University of Technology, SE-412 96, Göteborg, Sweden.
authors.forename: Stefan
authors.initials: S
authors.lastname: Hellström
authors.forename: Fengling
authors.initials: F
authors.lastname: Zhang
authors.forename: Olle
authors.initials: O
authors.lastname: Inganäs
authors.forename: Mats R
authors.initials: MR
authors.lastname: Andersson
mesh_terms: D011211:Electric Power Supplies; D004563:Electrochemistry; D015394:Molecular Structure; D008970:Molecular Weight; D010777:Photochemistry; D011108:Polymers / Q000737:chemistry*; D012993:Solar Energy; D013329:Structure-Activity Relationship
chemical_list: D011108:Polymers