Bismuth sulfide/carbon black: as a pt free and efficient counter electrode in DSSC

Abstract

A hydrothermal method was utilized to synthesize microstructures of bismuth sulfide (Bi2S3) across a range of reaction temperatures, spanning from 140 to 180 °C. The impact of varying reaction temperatures on the structural, morphological, and optical properties of the deposited Bi2S3 material was thoroughly examined. The x-ray diffraction (XRD) patterns confirmed the presence of an orthorhombic crystal structure. The formation of intricate three-dimensional Bi2S3 microstructures was evident under field emission scanning electron microscopy (FESEM), with the reaction temperature playing a pivotal role in this process. Furthermore, Bi2S3-carbon black composites were employed as the counter electrode in dye-sensitized solar cell (DSSC) applications. The current density–voltage characteristics of the DSSCs revealed a clear correlation between photoconversion efficiency and the reaction temperature. Notably, the Bi2S3-carbon black film with a 1:1 ratio achieved a peak photoelectric conversion efficiency of 4.37 ± 0.01%. It also exhibited a short-circuit current density of 10.29 mA cm−2 and an open-circuit potential of 0.70 V. Future studies should explore the broader implications of Bi2S3-carbon black composites in various optoelectronic and photocatalytic devices. Secondly, while our findings provide valuable insights, a more in-depth understanding of the underlying mechanisms governing the enhanced photoconversion efficiency, especially with the 1:1 ratio of Bi2S3-carbon black, requires further exploration.