Elucidating the Influence of Sodium Fluoride on the Structural and Photoelectrochemical Properties of Antimony Sulfide Thin Films

High Resolution Image Download MS PowerPoint Slide Photoelectrocatalysis has become a sustainable and eco-friendly method for water splitting, enabling the production of hydrogen and oxygen using solar energy. Among various photoabsorber materials, antimony sulfide (Sb 2 S 3 ) is regarded as a promising candidate for photoelectrochemical (PEC) water splitting due to its suitable band gap (∼1.7 eV), high optical absorption coefficient, and the earth-abundant nature of its elements. However, its practical application is limited by deep-level defects that can cause charge carrier recombination and reduce PEC efficiency. This work investigates how sodium fluoride (NaF) doping influences the structural, optical, and electrochemical properties of Sb 2 S 3 thin films. NaF doping modifies the surface morphology and decreases surface roughness. These structural changes are associated with an increase in photocurrent density from 0.48 to 0.52 mA cm –2 and a significant rise in carrier concentration from 9.24 × 10 15 to 3.47 × 10 18 cm –3 under standard illumination. These results demonstrate that NaF plays a key role in controlling charge transport and improving catalytic activity. Overall, the findings highlight how dopant-induced modifications affect the PEC performance of Sb 2 S 3 -based photoelectrodes.