Annealing effect on Sb₂S₃/c-Si structure for photovoltaic applications

Tandem solar cells present an efficient way to boost solar energy conversion, potentially advancing performance and widespread photovoltaic technology adoption. This study employed a novel approach to grow Sb₂S₃ thin films onto a c-Si (100) substrate using a sol-gel dip-coating technique. The as-deposited samples exhibited an amorphous nature, indicating the necessity for a thermal annealing step. The impact of annealing temperature on the phase purity, structure, morphological, optical, and photovoltaic properties of the synthesized hetero-structure Sb₂S₃/c-Si (100) was examined using secondary ion mass spectrometry (SIMS), X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDS), and UV-visible spectroscopy. SIMS analysis revealed uniformity and consistent composition in the deposited films with a thickness of approximately 700 nm on the silicon substrate. XRD measurements revealed a polycrystalline structure in all films after annealing in an argon atmosphere, except for the as-deposited one. The Sb₂S₃ film annealed at 320 °C exhibited the highest crystallite size of about 53 nm. The optical parameters such as refractive index n(λ) and extinction coefficient k(λ) were estimated using the Fresnel matrix method. The Sb₂S₃/c-Si heterojunction exhibited obvious rectification characteristics according to the current vs. voltage (I-V) curve under dark conditions. The illuminated current density-voltage characteristic of the best hetero-junction Ag/ Sb₂S₃/c-Si (100)/Al annealed at 320 °C exhibits a short-circuit current density (J_sc) of 13.16 mA cm^− 2, an open circuit voltage (V_oc) of 730 mV, and fill factor (FF) of 0.62 yielding power conversion efficiencies (PCE) of 6.15%.under AM 1.5 sun.