An appropriate solution is suggested for synthesizing wafer-scale, continuous, and stoichiometric MoS2 layers with spatial homogeneity at the low temperature of 450 degrees C. It is also demonstrated that the MoS2-based visible-light photodetector arrays are both fabricated on 4 inch SiO2/Si wafer and polyimide films, revealing 100% active devices with a narrow photocurrent distribution and excellent mechanical durability.