title: 3D hierarchical rutile TiO2 and metal-free organic sensitizer producing dye-sensitized solar cells 8.6% conversion efficiency.
abstract: Three-dimensional (3D) hierarchical nanoscale architectures comprised of building blocks, with specifically engineered morphologies, are expected to play important roles in the fabrication of 'next generation' microelectronic and optoelectronic devices due to their high surface-to-volume ratio as well as opto-electronic properties. Herein, a series of well-defined 3D hierarchical rutile TiO2 architectures (HRT) were successfully prepared using a facile hydrothermal method without any surfactant or template, simply by changing the concentration of hydrochloric acid used in the synthesis. The production of these materials provides, to the best of our knowledge, the first identified example of a ledgewise growth mechanism in a rutile TiO2 structure. Also for the first time, a Dye-sensitized Solar Cell (DSC) combining a HRT is reported in conjunction with a high-extinction-coefficient metal-free organic sensitizer (D149), achieving a conversion efficiency of 5.5%, which is superior to ones employing P25 (4.5%), comparable to state-of-the-art commercial transparent titania anatase paste (5.8%). Further to this, an overall conversion efficiency 8.6% was achieved when HRT was used as the light scattering layer, a considerable improvement over the commercial transparent/reflector titania anatase paste (7.6%), a significantly smaller gap in performance than has been seen previously.
authors.affiliation: Institute for Superconducting and Electronic Materials (ISEM), Australian Institute for Innovative Materials (AIIM), University of Wollongong, NSW 2522, Australia.
authors.forename: Jianjian
authors.initials: J
authors.lastname: Lin
authors.affiliation: Graduate Institute for Ferrous Technology, Pohang University of Science and Technology, San 31, Hyoja-dong, Pohang 790-784, Republic of Korea.
authors.forename: Yoon-Uk
authors.initials: YU
authors.lastname: Heo
authors.affiliation: Intelligent Polymer Research Institute, ARC Centre of Excellence for Electromaterials Science, AIIM, University of Wollongong, NSW 2522, Australia.
authors.forename: Andrew
authors.initials: A
authors.lastname: Nattestad
authors.affiliation: Institute for Superconducting and Electronic Materials (ISEM), Australian Institute for Innovative Materials (AIIM), University of Wollongong, NSW 2522, Australia.
authors.forename: Ziqi
authors.initials: Z
authors.lastname: Sun
authors.affiliation: Nanomaterials Centre, School of Chemical Engineering and Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia.
authors.forename: Lianzhou
authors.initials: L
authors.lastname: Wang
authors.affiliation: Institute for Superconducting and Electronic Materials (ISEM), Australian Institute for Innovative Materials (AIIM), University of Wollongong, NSW 2522, Australia.
authors.forename: Jung Ho
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Institute for Superconducting and Electronic Materials (ISEM), Australian Institute for Innovative Materials (AIIM), University of Wollongong, NSW 2522, Australia.
authors.forename: Shi Xue
authors.initials: SX
authors.lastname: Dou