Preparation and Characterizations of the High UV Sensitivity Porous Diamond-Like Carbon Thin Film MSM Photodiodes

For the first time, we use a porous diamond-like carbon (DLC) film formed on a porous Si substrate to promote its ultraviolet (UV) quantum efficiency. With the porous DLC films, we developed metal-semiconductor-metal (MSM) photodiodes for UV detecting applications. The morphology and structure of the porous DLC film were analyzed with SEM photos for both top and cross section views. Besides, we examined the responses of the diodes to UV light by measurement of the photo/dark current ratio with and without the irradiation of a 366 nm UV light. Experiments show the current ratio and quantum efficiency are respectively promoted ~570% and ~76% under -15 V bias by the porous structure.