Effect of Valeric Acid as a Co-adsorbate on the Performance of Dye-Sensitized Solar Cells

Abstract

We investigated effects of valeric acid (VA) as a co-adsorbate on the photovoltaic performance of dye-sensitized solar cells (DSSCs). When the introduction of VA onto TiO₂surface was performed after dye (N719) adsorption, the DSSC with VA showed an increase in short-circuit current (J_sc ), open-circuit voltage (V_oc ) and fill factor, resulting in a power conversion efficiency of 7.27%, compared to that (6.20%) of reference device without VA. Incorporation of VA on free TiO₂surface induced longer lifetime of electrons injected from excited dyes to conduction band of TiO₂, leading to the increase of electron collection efficiency and the suppression of charge recombination between injected electrons and I₃ ⁻ions, and thus larger J_sc and V_oc , respectively.

Keywords:

• Charge recombination
• co-adsobate
• dye-sensitized solar cell
• valeric acid

Acknowledgment

This work was supported by the Gyeongbuk Science & Technology Promotion Center (GBSP) grant funded by the Korea government (MEST) (GBSP-001-120705-01).