Copper-indium-sulfide colloids on quantum dot sensitized TiO2 solar cell: Effects of capping with mercapto-acid linker molecules

Shinya Higashimoto; Takuto Nakase; Shun Mukai; Masanari Takahashi

doi:10.1016/j.jcis.2018.09.092

Copper-indium-sulfide colloids on quantum dot sensitized TiO₂ solar cell: Effects of capping with mercapto-acid linker molecules

J Colloid Interface Sci. 2019 Feb 1:535:176-181. doi: 10.1016/j.jcis.2018.09.092. Epub 2018 Sep 27.

Authors

Shinya Higashimoto¹, Takuto Nakase², Shun Mukai², Masanari Takahashi³

Affiliations

¹ College of Engineering, Osaka Institute of Technology, 5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan. Electronic address: shinya.higashimoto@oit.ac.jp.
² College of Engineering, Osaka Institute of Technology, 5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan.
³ Osaka Research Institute of Industrial Science and Technology, 1-6-50 Morinomiya, Joto-ku, Osaka 536-8553, Japan.

PMID: 30293043
DOI: 10.1016/j.jcis.2018.09.092

Abstract

The copper-indium-sulfide (CIS) ternary colloids were synthesized in "green" water solvent at room temperature employing mercapto-alkyl carboxylic linker molecules such as thioglycolic acid (TGA), thioacetic acid (TAA), 2-mercaptopropionic acid (2-MPA) and l-cysteine (Cys). The stability of the CIS colloids is strongly influenced by the structures of linker molecules, and short linker molecules induce strong adsorption of the CIS colloids on the TiO₂, exhibiting strong visible-light absorption and high photo-conductivities. Effects of linker molecules capping CIS colloids on the solar cell performances were demonstrated. The solar cell performances for the CIS-TiO₂ improve as an increase of photo-conductivity of the CIS-TiO₂ electrodes. In particular, the CIS(TAA)-TiO₂ photoelectrode employing the shortest linker molecules (TAA) exhibited the highest PCE yielding with 6.33% (short-circuit current: 14.0 mA/cm², open-circuit voltage: 0.91 V and fill factor: 48.0%).

Keywords: Copper-indium-sulfide (CIS) colloids; Linker molecules; Photo-conversion efficiency (PCE); Quantum dot; Solar cell.