Issue 3, 2013

Harnessing the open-circuit voltage via a new series of Ru(ii) sensitizers bearing (iso-)quinolinyl pyrazolate ancillaries

Abstract

A novel class of Ru(II) sensitizers (TFRS-51–TFRS-54) with a 4,4′-dicarboxy-2,2′-bipyridine anchoring ligand and two trans-oriented isoquinolinyl (or quinolinyl) pyrazolate ancillaries were designed, characterized and used to fabricate dye sensitized solar cell (DSC) devices. In sharp contrast to Ru(II) sensitizers that employ functionalized thiophene appendages in their ancillary bipyridal ligands, the extended π-conjugation introduced by the isoquinolinyl or quinolinyl groups improves the optical absorptivity, particularly for the absorption located at ∼500 nm when compared with the parent sensitizer TFRS-1 possessing less conjugated 5-pyrid-2-yl pyrazolate ancillaries. As a result, DSCs incorporated with these dyes show much improved JSC compared with the reference device. Moreover, the use of bulky t-butyl substituents on the ancillary ligands improves the cell performance with excellent VOC of up to 830 mV recorded. Also, the addition of tetra-n-butyl ammonium deoxycholate [TBA][DOC] as co-adsorbent to the dye solution further improves the power conversion efficiency (η). The best solar cell parameters recorded were JSC = 16.3 mA cm−2, VOC = 860 mV, FF = 0.72, and η = 10.1% for a device sensitized with TFRS-52. The markedly high open-circuit voltage is confirmed by the longer electron lifetime revealed in transient photovoltage (TPV) measurement versus the TFRS-1 sensitizer, and is probably derived from a combination of the higher conduction band edge of TiO2 induced by the in situ metathesis of carboxylate anchors and the reduced recombination contributed by the bulky sensitizer.

Graphical abstract: Harnessing the open-circuit voltage via a new series of Ru(ii) sensitizers bearing (iso-)quinolinyl pyrazolate ancillaries

Supplementary files

Article information

Article type
Paper
Submitted
06 Nov 2012
Accepted
07 Jan 2013
First published
07 Jan 2013

Energy Environ. Sci., 2013,6, 859-870

Harnessing the open-circuit voltage via a new series of Ru(II) sensitizers bearing (iso-)quinolinyl pyrazolate ancillaries

K. Wu, W. Ku, J. N. Clifford, E. Palomares, S. Ho, Y. Chi, S. Liu, P. Chou, M. K. Nazeeruddin and M. Grätzel, Energy Environ. Sci., 2013, 6, 859 DOI: 10.1039/C2EE23988D

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements