High performance of TiO2 based solar cells sensitized with copper-indium sulfide colloids prepared in water: Roles of surface modifications with indium sulfide and zinc sulfide by SILAR methods. (20th December 2016)

• Record Type: Journal Article
• Authors: Higashimoto, Shinya; Okada, Tsubasa; Arase, Taisuke; Azuma, Masashi; Yamamoto, Mari; Takahashi, Masanari
• Is Part Of: Electrochimica acta. Volume 222(2016)
• Page Start: 867
• Page End: 874
• Publication Date: 2016-12-20
• Subjects: Quantum dot sensitized solar cell -- CIS colloid -- SILAR -- photoconversion efficiency; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2016.11.051
• Languages: English
• ISSNs: 0013-4686

Abstract

Graphical abstract: Highlights: The copper-indium-sulfide colloidal solutions were prepared in water. The CIS-TiO2 photoelectrode modified with In2 S3 and ZnS exhibited high PCE of 4.39%. The In2 S3 improves light absorption of CIS and cathodic shift of the Fermi level. The ZnS works for blocking the back electron transfer at the electrolyte interface. Abstract: The copper-indium-sulfide (CIS) ternary colloids capped with thioglycolic acid were directly prepared in water, and these hydrophilic colloids were strongly adsorbed on the TiO2 to form CIS-TiO2 photoelectrodes without ligand-exchange. Furthermore, the photoelectrodes were modified with indium sulfide and/or zinc sulfide phases via successive ionic layer adsorption and reaction (SILAR). The preferable CIS-TiO2 photoelectrode exhibited the photo-conversion efficiency (PCE) yielding with 4.39%, which is the highest value among the solar cell employing CIS colloids prepared in water at room temperature. The origin of high solar cell performance is attributed to the post surface modifications: the SILAR treatment by In 3+ /S 2− ions improves light absorption of CIS and cathodic shift of the Fermi level due to the reduction of vacancies, while that by Zn 2+ /S 2− ions forms passivation layers for blocking the back electron transfer at the interface between the electrode and electrolyte for retarding charge-recombination. The synergetic effects by surface modifications of the CIS-TiO2 thus improved the PCE of the solar cell.