title: Three-dimensional self-assembly of networked branched TiO₂ nanocrystal scaffolds for efficient room-temperature processed depleted bulk heterojunction solar cells.
abstract: In this work, we report on ∼4% power conversion efficiency (PCE) depleted bulk heterojunction (DBH) solar cells based on a high-quality electrode with a three-dimensional nanoscale architecture purposely designed so as to maximize light absorption and charge collection. The newly conceived architecture comprises a mesoporous electron-collecting film made of networked anisotropic metal-oxide nanostructures, which accommodates visible-to-infrared light harvesting quantum dots within the recessed regions of its volume. The three-dimensional electrodes were self-assembled by spin-coating a solution of colloidal branched anatase TiO2 NCs (BNC), followed by photocatalytic removal of the native organic capping from their surface by a mild UV-light treatment and filling with small PbS NCs via infiltration. The PCE ∼ 4% of our TiO2 BNC/PbS QD DBH solar cell features an enhancement of 84% over the performance obtained for a planar device fabricated under the same conditions. Overall, the DBH device fabrication procedure is entirely carried out under mild processing conditions at room temperature, thus holding promise for low-cost and large-scale manufacturing.
authors.affiliation: CBN - Center for Biomolecular Nanotechnologies - Italian Institute of Technology - Energy Platform - Via Barsanti sn, 73010 Arnesano (Lecce), Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Loiudice
authors.forename: Giulia
authors.initials: G
authors.lastname: Grancini
authors.forename: Antonietta
authors.initials: A
authors.lastname: Taurino
authors.forename: Michela
authors.initials: M
authors.lastname: Corricelli
authors.forename: Maria R
authors.initials: MR
authors.lastname: Belviso
authors.forename: Marinella
authors.initials: M
authors.lastname: Striccoli
authors.forename: Angela
authors.initials: A
authors.lastname: Agostiano
authors.forename: M Lucia
authors.initials: ML
authors.lastname: Curri
authors.forename: Annamaria
authors.initials: A
authors.lastname: Petrozza
authors.forename: P Davide
authors.initials: PD
authors.lastname: Cozzoli
authors.forename: Aurora
authors.initials: A
authors.lastname: Rizzo
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Gigli