title: Solution-Processed Small-Molecule Bulk Heterojunctions: Leakage Currents and the Dewetting Issue for Inverted Solar Cells.
abstract: In organic photovoltaic (PV) devices based on solution-processed small molecules, we report here that the physicochemical properties of the substrate are critical for achieving high-performances organic solar cells. Three different substrates were tested: ITO coated with
  PSS, ZnO sol-gel, and ZnO nanoparticles. PV performances are found to be low when the ZnO nanoparticles layer is used. This performance loss is attributed to the formation of many dewetting points in the active layer, because of a relatively high roughness of the ZnO nanoparticles layer, compared to the other layers. We successfully circumvented this phenomenon by adding a small quantity of polystyrene (PS) in the active layer. The introduction of PS improves the quality of film forming and reduces the dark currents of solar cells. Using this method, high-efficiency devices were achieved, even in the case of substrates with higher roughness.
authors.affiliation: Université de Bordeaux, IMS, UMR 5218, F-33400 Talence, France.|ARMOR, 20, rue Chevreul - BP 90508 44105, Nantes, France.
authors.forename: Elodie
authors.initials: E
authors.lastname: Destouesse
authors.affiliation: Université de Bordeaux, IMS, UMR 5218, F-33400 Talence, France.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Chambon
authors.affiliation: ARMOR, 20, rue Chevreul - BP 90508 44105, Nantes, France.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Courtel
authors.affiliation: Université de Bordeaux, IMS, UMR 5218, F-33400 Talence, France.
authors.forename: Lionel
authors.initials: L
authors.lastname: Hirsch
authors.affiliation: Université de Bordeaux, IMS, UMR 5218, F-33400 Talence, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Wantz
keywords: dewetting; filming properties; organic photovoltaics; p-DTS(FBTTh2)2; solution processable small molecule