This study reports a self-powered 3C-SiC/Si heterostructure photodetector in both metal-semiconductor-metal (MSM) and heterojunction (HET) configurations and capable of operating under ultraviolet and visible light (UV-VIS). The single crystalline 3C-SiC thin film was grown epitaxially on a Si (111) substrate by employing a two-step growth process. MSM configuration exhibited a peak responsivity of 0.334 A/W and a specific detectivity of 5.4 x 1011 cm.Hz1/2.W-1 (Jones) under white light illumination. However, in the UV region, photocurrent showed an increasing behavior with a decrease in the UV wavelength from 365 nm to 254 nm. The peak responsivity and specific detectivity values of the HET configuration were also determined under white light illumination with 0.167 A/W and 4.4 x 1011 Jones, respectively. Furthermore, both devices exhibited very fast rise and decay times as 3.8 ms and 3.6 ms for the MSM, and 6 ms and 8 ms for the HET configuration (fastest reported on 3C-SiC). In brief, our self-powered 3C-SiC/Si heterostructure with multiband (UV-VIS) photodetection sensitivity and fast speed could offer new solutions for the eco-friendly and sustainable optoelectronic applications.