Ultrasonic spray pyrolysis-assisted preparation of CoS for stable, uniform and efficient counter electrode in dye-sensitized solar cells

Abstract

Searching for large-scale, non-Pt, efficient counter electrode (CE) materials is still a key challenge to realize the applications of high-performance dye-sensitized solar cells (DSSCs). Herein, we report the spray fabrication of stable, uniform and efficient CoS counter electrode at temperature no higher than 100 °C from CoS nanoparticles prepared by the ultrasonic spray pyrolysis (USP) method. The as-fabricated USP-assisted CoS CEs exhibit comparable electrocatalytic activity to the traditional thermolyzed Pt CE, generating a power conversion efficiency of 8.6% for unoptimized DSSCs. This CoS CEs also exhibited prominent electrochemical and mechanical stability, uniform electrocatalytic activity at the size of 10 × 10 cm, and good bending durability when deposited on flexible ITO/PEN conductive substrates, manifesting the merits of this USP-based strategy for the development of high-performance non-Pt electrocatalysts.