title: High-efficiency ferroelectric-film solar cells with an n-type Cu₂O cathode buffer layer.
abstract: Because of the existence of interface Schottky barriers and depolarization electric field, ferroelectric films sandwiched between top and bottom electrodes are strongly expected to be used as a new kind of solar cells. However, the photocurrent with a typical order of μA/cm(2) is too low to be practical. Here we demonstrate that the insertion of an n-type cuprous oxide (Cu(2)O) layer between the Pb(Zr,Ti)O(3) (PZT) film and the cathode Pt contact in a ITO/PZT/Pt cell leads to the short-circuit photocurrent increasing 120-fold to 4.80 mA/cm(2) and power conversion efficiency increasing of 72-fold to 0.57% under AM1.5G (100 mW/cm(2)) illumination. Ultraviolet photoemission spectroscopy and dark J-V characteristic show an ohmic contact on Pt/Cu(2)O, an n(+)-n heterojunction on Cu(2)O/PZT and a Schottky barrier on PZT/ITO, which provide a favorable energy level alignment for efficient electron-extraction on the cathode. Our work opens up a promising new method that has the potential for fulfilling cost-effective ferroelectric-film photovoltaic.
authors.affiliation: Department of Physics and Jiangsu Key Laboratory of Thin Films, Soochow University, Suzhou 215006, People's Republic of China.
authors.forename: Dawei
authors.initials: D
authors.lastname: Cao
authors.forename: Chunyan
authors.initials: C
authors.lastname: Wang
authors.forename: Fengang
authors.initials: F
authors.lastname: Zheng
authors.forename: Wen
authors.initials: W
authors.lastname: Dong
authors.forename: Liang
authors.initials: L
authors.lastname: Fang
authors.forename: Mingrong
authors.initials: M
authors.lastname: Shen
mesh_terms: D003300:Copper / Q000737:chemistry*; D011211:Electric Power Supplies; D004566:Electrodes; D004735:Energy Transfer; D004867:Equipment Design; D019544:Equipment Failure Analysis; D060526:Magnetic Fields; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D012666:Semiconductors; D012993:Solar Energy
chemical_list: D003300:Copper; C030973:cupric oxide