Enhanced photovoltaic performance using one-dimensional polyaniline nanowires decorated with two-dimensional tungsten disulfide nanoflakes as a binary composite counter electrode for solar cell studies

Abstract

In this work, the poly (aniline) decorated tungsten sulfide (1D PANI@2D WS₂) composite was prepared as a counter electrode (CE) for dye-sensitized solar cell (DSSC) studies. FE-SEM images showed that 2D WS₂ displayed a flower-like structure, and 1D PANI exhibited a fiber like-structure, while the 1D PANI@2D WS₂ composite appeared as a 1D PANI polymer covered flower-like structure of 2D WS₂. TEM images further confirmed that 1D PANI nanofibers were surrounding the flower-like tungsten sulfide. XRD pattern analysis indicated that the as-prepared 1D PANI@2D WS₂ composite possessed an octahedral crystalline structure, with an average crystanillity of 63.49 %. The CV studies of composite demonstrated enhanced electrocatalytic activity for iodide/tri-iodide (I⁻/I³⁻) regeneration at the CE surface. Additionally, the EIS studies revealed that the 1D PANI@2D WS₂ composite CE exhibited the high electrical conductivity of 6.23 × 10⁻³ Scm⁻¹. DSSCs assembled the 2D WS₂, 1D PANI, 1DPANI@2D WS₂ composite, and Pt as CEs, with N719 dye soaked TiO₂ NPs as photo-anode. The 1-butyl-3-methylimidazolium iodide, potassium iodide, iodine, and poly (ethylene oxide) used as electrolyte medium. Among these DSSC device, the 1D PANI@2D WS₂ composite CE achieved an efficiency of 7.28 %. The reproducibility studies of the binary composite CE was conducted over approximately 30 days. After this period, the composite CE achieved an efficiency of 6.24 %. Furthermore, the maximum incident photon-to-charge carrier efficiency (IPCE) for the DSSCs utilizing the 1D PANI@2D WS₂ composite CE was recorded at 73.21 %, surpassing the 66.12 % efficiency of the DSSC with the Pt CE.