This study investigates the charge separation mechanism at the interface between Sb2S3 and CuSCN layers in solid-state solar cells using transient absorption spectroscopy. The researchers analyzed films with and without a hole conductor layer to determine the hole trapping rate in Sb2S3 and hole transfer rate at the interface. They found correspondence between the decay of photogenerated holes at 460 nm and growth of sulfide radicals at 560 nm, indicating hole trapping in Sb2S3. Comparison of films with and without CuSCN allowed calculation of the hole transfer rate from Sb2S3 to CuSCN. The study provides insight into the dynamics and limiting factors for performance of Sb2S3 solid