Investigation of Ti-DLC film for the near infrared photodetector

Diamond-like carbon (DLC) combines the excellent properties of diamond and graphite and has the feature of a tunable band gap, which can be used as a photodetector. Here, we propose a Ti-DLC/Si heterojunction photodetector. Uniform DLC films were co-deposited on silicon by magnetron sputtering, and the effect of titanium doping on the films was investigated. Meanwhile, Ti-DLC/Si heterojunctions were prepared, and the optical responsiveness of DLC devices with different thicknesses was investigated in the 1550 nm band. The device exhibited a detectivity of 1.16 × 108 Jones, a response time of 5 ms for rising edges and 3 ms for falling edges at a DLC thickness of 90 nm. This work presents a broad application prospect in the field of photodetectors.