title: Trap-Assisted Transport and Non-Uniform Charge Distribution in Sulfur-Rich PbS Colloidal Quantum Dot-based Solar Cells with Selective Contacts.
abstract: This study reports evidence of dispersive transport in planar PbS colloidal quantum dot heterojunction-based devices as well as the effect of incorporating a MoO3 hole selective layer on the charge extraction behavior. Steady state and transient characterization techniques are employed to determine the complex recombination processes involved in such devices. The addition of a selective contact drastically improves the device efficiency up to 3.15% (especially due to increased photocurrent and decreased series resistance) and extends the overall charge lifetime by suppressing the main first-order recombination pathway observed in device without MoO3. The lifetime and mobility calculated for our sulfur-rich PbS-based devices are similar to previously reported values in lead-rich quantum dots-based solar cells. Nevertheless, strong Shockley-Read-Hall mechanisms appear to keep restricting charge transport, as the equilibrium voltage takes more than 1 ms to be established.
authors.affiliation: Institute for Superconducting and Electronic Materials (ISEM), Australian Institute for Innovative Materials, University of Wollongong , North Wollongong, New South Wales 2500, Australia.|World Premier International (WPI) Research Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS) , 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
authors.forename: Victor
authors.initials: V
authors.lastname: Malgras
authors.affiliation: Intelligent Polymer Research Institute (IPRI), ARC Centre of Excellence for Electromaterials Science, University of Wollongong , North Wollongong, New South Wales 2500, Australia.
authors.forename: Guanran
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Intelligent Polymer Research Institute (IPRI), ARC Centre of Excellence for Electromaterials Science, University of Wollongong , North Wollongong, New South Wales 2500, Australia.
authors.forename: Andrew
authors.initials: A
authors.lastname: Nattestad
authors.affiliation: Intelligent Polymer Research Institute (IPRI), ARC Centre of Excellence for Electromaterials Science, University of Wollongong , North Wollongong, New South Wales 2500, Australia.
authors.forename: Tracey M
authors.initials: TM
authors.lastname: Clarke
authors.affiliation: Intelligent Polymer Research Institute (IPRI), ARC Centre of Excellence for Electromaterials Science, University of Wollongong , North Wollongong, New South Wales 2500, Australia.
authors.forename: Attila J
authors.initials: AJ
authors.lastname: Mozer
authors.affiliation: World Premier International (WPI) Research Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS) , 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Yamauchi
authors.affiliation: Institute for Superconducting and Electronic Materials (ISEM), Australian Institute for Innovative Materials, University of Wollongong , North Wollongong, New South Wales 2500, Australia.
authors.forename: Jung Ho
authors.initials: JH
authors.lastname: Kim
keywords: lead sulfide; lifetime; photovoltaic; quantum dots; recombination; solar cells; transport