title: Defective TiO2 with high photoconductive gain for efficient and stable planar heterojunction perovskite solar cells.
abstract: Formation of planar heterojunction perovskite solar cells exhibiting both high efficiency and stability under continuous operation remains a challenge. Here, we show this can be achieved by using a defective TiO2 thin film as the electron transport layer. TiO2 layers with native defects are deposited by electron beam evaporation in an oxygen-deficient environment. Deep-level hole traps are introduced in the TiO2 layers and contribute to a high photoconductive gain and reduced photocatalytic activity. The high photoconductivity of the TiO2 electron transport layer leads to improved efficiency for the fabricated planar devices. A maximum power conversion efficiency of 19.0% and an average PCE of 17.5% are achieved. In addition, the reduced photocatalytic activity of the TiO2 layer leads to enhanced long-term stability for the planar devices. Under continuous operation near the maximum power point, an efficiency of over 15.4% is demonstrated for 100 h.
authors.affiliation: Joint Center for Artificial Photosynthesis, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA.|Chemical Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA.
authors.forename: Yanbo
authors.identifier: 0000-0002-3017-762X
authors.initials: Y
authors.lastname: Li
authors.affiliation: Joint Center for Artificial Photosynthesis, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA.|Chemical Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA.
authors.forename: Jason K
authors.initials: JK
authors.lastname: Cooper
authors.affiliation: Joint Center for Artificial Photosynthesis, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA.|Chemical Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA.
authors.forename: Wenjun
authors.initials: W
authors.lastname: Liu
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA.|Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720, USA.
authors.forename: Carolin M
authors.initials: CM
authors.lastname: Sutter-Fella
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA.|Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720, USA.
authors.forename: Matin
authors.initials: M
authors.lastname: Amani
authors.affiliation: Joint Center for Artificial Photosynthesis, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA.|Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA.
authors.forename: Jeffrey W
authors.initials: JW
authors.lastname: Beeman
authors.affiliation: Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720, USA.
authors.forename: Ali
authors.initials: A
authors.lastname: Javey
authors.affiliation: Joint Center for Artificial Photosynthesis, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA.|Materials Science and Engineering, University of California, Berkeley, California 94720, USA.
authors.forename: Joel W
authors.initials: JW
authors.lastname: Ager
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA.|Molecular Foundry, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Joint Center for Artificial Photosynthesis, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA.|Chemical Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA.
authors.forename: Francesca M
authors.initials: FM
authors.lastname: Toma
authors.affiliation: Joint Center for Artificial Photosynthesis, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA.|Chemical Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA.
authors.forename: Ian D
authors.initials: ID
authors.lastname: Sharp