A Promising Modified SILAR Sequence for the Synthesis of Photoelectrochemically Active Cu₂ZnSnS₄ (CZTS) Thin Films

A promising modified SILAR sequence approach has been employed for the synthesis of photoelectrochemically active Cu₂ZnSnS₄ (CZTS) thin films. To study the influence of sulfurization temperatures on the CZTS thin films, the CZTS precursor thin films were annealed at temperatures of 520, 540, 560, and 580 °C for 1 h in an H₂S (5 %)+Ar (95 %) atmosphere. These films were characterized for their structural, morphological, and optical properties using X-ray diffraction, Raman spectroscopy, field emission scanning electron microscopy, and UV-vis spectrophotometer techniques. The film sulfurized at an optimized temperature of 580 °C shows the formation of a prominent CZTS phase with a dense microstructure and optical band gap energy of 1.38 eV. The photoelectrochemical (PEC) device fabricated using optimized CZTS thin films sulfurized at 580 °C exhibits an open circuit voltage (V_oc) of 0.38 V and a short circuit current density (J_sc) of 6.49 mA cm^-2, with a power conversion efficiency (η) of 0.96 %.