Si-based tandem solar cells have emerged as a promising alternative to replace the current high efficiency silicon single junction solar cells. Sb2S3 is a promising candidates for top cell absorbers due to its suitable band gap, non-toxic and earth-abundant constituent, simple composition, and long term stability. Here, in situ growth of Sb2S3 thin films by radio frequency (RF) reactive sputtering on n-Si(100) substrates is reported. The effects of the growth temperature on morphology, structure, optical and electrical properties of the films were evaluated. The top sub-cell device shows an open circuit voltage (Voc) of 367 mV, indicating the potential to be the top cell of the next generation Si-based tandem solar cells.