Effects of metallic interlayers on the performance of nanocrystalline diamond metal-semiconductor-metal photodetectors

•The MSM photodetectors have successfully prepared using nanocrystalline diamond (NCD) films and metallic layers.•The metallic interlayers reduce the surface roughness of the fabricated NCD films from 8.3 nm to 4.7 nm.•The W/NCD/W MSM photodetector possesses a high photo-to-dark current ratio about 3 orders of magnitude.