Klein, Y. M. and Willgert, M. and Prescimone, A. and Constable, E. C. and Housecroft, C. E.. (2016) Positional isomerism makes a difference: phosphonic acid anchoring ligands with thienyl spacers in copper(I)-based dye-sensitized solar cells. Dalton transactions, 45 (11). pp. 4659-4672.
|
PDF
- Published Version
Available under License CC BY (Attribution). 3207Kb |
Official URL: http://edoc.unibas.ch/41917/
Downloads: Statistics Overview
Abstract
With the aim of improving the photoconversion efficiencies of heteroleptic [Cu(Lanchor)(Lancillary)](+) dyes in n-type dye-sensitized solar cells (DSCs), the previously favoured anchor ((6,6'-dimethyl-[2,2'-bipyridine]-4,4'-diyl)bis(4,1-phenylene))bis(phosphonic acid) (1) has been replaced by analogues 2 and 3 containing 2-thienyl spacers between the 2,2'-bipyridine metal-binding domain and the phosphonic acid anchoring groups. The synthesis and characterization of 2 and 3 (2-thienyl spacer with phosphonic acid in the 5- and 4-positions, respectively) are reported. A stepwise, on-surface method was used to assemble [Cu(Lanchor)(Lancillary)](+) dyes onto FTO/TiO2 electrodes with Lanchor = 1, 2 or 3, and Lancillary = 6,6'-bis(trifluoromethyl)-2,2'-bipyridine (4), 6-trifluoromethyl-2,2'-bipyridine (5), 6,6'-dimethyl-2,2'-bipyridine (6), and 6-methyl-2,2'-bipyridine (7). Changing the solvent in the dye-bath from CH2Cl2 to acetone had only a small effect on the photoconversion efficiencies of [Cu(1)(4)](+), [Cu(1)(5)](+) and [Cu(1)(6)](+); the optimal dye in this series was [Cu(1)(5)](+). Comparable DSC performances were achieved by using either anchor 1 or 2, but there is improved electron injection if the phosphonic acid group is in the 4- rather than 5-position of the thienyl ring (i.e. anchor 3 is superior to 2). Similar open-circuit voltages (VOC) are achieved on going from 1 to 3 with a given Lancillary; although there is typically a gain in short-circuit current denisty (JSC) on going from 1 or 3 to 2, there is an ≈50-60 mV drop in VOC on introducing 2 as the anchor. The best photoconversion efficiencies are obtained for the dye [Cu(3)(5)](+) (η = 2.40% relative to an N719 reference of 5.76%). The conclusions reached from plots of current-density (J) against potential (V), and external quantum efficiency spectra are supported by electrochemical impedance spectroscopic measurements.
Faculties and Departments: | 05 Faculty of Science > Departement Chemie > Former Organization Units Chemistry > Anorganische Chemie (Constable) 05 Faculty of Science > Departement Chemie > Former Organization Units Chemistry > Anorganische Chemie (Housecroft) |
---|---|
UniBasel Contributors: | Housecroft, Catherine Elizabeth and Constable, Edwin Charles and Prescimone, Alessandro and Willgert, Markus and Klein, Maximilian |
Item Type: | Article, refereed |
Article Subtype: | Research Article |
Publisher: | Royal Society of Chemistry |
ISSN: | 1477-9226 |
Note: | Publication type according to Uni Basel Research Database: Journal article |
Language: | English |
Identification Number: |
|
edoc DOI: | |
Last Modified: | 30 Jun 2016 11:03 |
Deposited On: | 20 Jun 2016 12:43 |
Repository Staff Only: item control page