Change search
ReferencesLink to record
Permanent link

Direct link
Insight into Benzothiadiazole Acceptor in D-A-pi-A Configuration on Photovoltaic Performances of Dye-Sensitized Solar Cells
Show others and affiliations
2014 (English)In: ACS Sustainable Chemistry and Engineering, ISSN 2168-0485, Vol. 2, no 4, 1026-1034 p.Article in journal (Refereed) Published
Abstract [en]

The option of conjugated pi-linkers is critical for molecular engineering toward the energy-level strategy of donor-pi-acceptor (D-pi-A) sensitizers. There is always a balance in the optimization of a it-linker. The pi-conjugation should be enlarged to expand the light-harvesting capability of sensitizers for an increase in photocurrent; however, the oversized it-linker also would affect seriously the photovoltage and photostability. Two sensitizers, WS-22 and WS-23, are constructed without or with benzothiadiazole (BTD) in a molecular skeleton, aiming to gain insight into the effect of an auxiliary acceptor in D-A-pi-A sensitizers on the photophysical and photovoltaic performances, especially focusing on the exploitation of the short circuit current density (J(sc)) and open circuit voltage (V-oc). Compared with the typical D-pi-A sensitizer WS-22, the incorporation of an auxiliary acceptor of BTD in WS-23 can improve the light-harvesting ability both in red-shifting the absorption peaks and the increment of absorption coefficient. The predominant increase by 15.6% in light-harvesting efficiency (LHE) of WS-23 results in a relatively higher J(sc) from 13.77 (WS-22) to 16.91 mA cm(-2) (WS-23). Moreover, the improvement of the V-oc in WS-23 is originated by a synergy contribution of the uplifting of E-CB and inhibition of charge recombination. The stepped light-induced transient (SLIT) measurements indicate that the introduction of BTD can negatively shift the conduction band of the TiO2 film. For WS-23, the higher molecular dipole moment can bring forth a more effective charge separation between donor and acceptor units, also resulting in an increase in V-oc. The incorporated BTD unit can increase V-oc by 57 mV, arising from the CB edge shift of TiO2 (accounting for 40%, 23 mV) and the retarding charge recombination (accounting for 60%, 34 mV). As a consequence, WS-23 realizes an optimizing photovoltaic efficiency (eta = 8.15%), with an improvement of 36.5% with respect to WS-22.

Place, publisher, year, edition, pages
2014. Vol. 2, no 4, 1026-1034 p.
Keyword [en]
Organic sensitizers, Benzothiadiazole, Auxiliary acceptor, Solar cells, Photovoltaic performances
National Category
Chemical Sciences
URN: urn:nbn:se:kth:diva-145269DOI: 10.1021/sc500035jISI: 000334092600061ScopusID: 2-s2.0-84898000563OAI: diva2:717475

QC 20140515

Available from: 2014-05-15 Created: 2014-05-15 Last updated: 2014-05-15Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Search in DiVA

By author/editor
Li, XinÅgren, Hans
By organisation
Theoretical Chemistry and Biology
Chemical Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 22 hits
ReferencesLink to record
Permanent link

Direct link