Improving the light-response of platinum doped silicon MSM photodetectors using X-ray irradiation

This research presents a new result to improve optical response characteristics of Metal-Semiconductor-Metal (MSM) photodetectors with Cr/n-Si/Cr structure. Experimental results compare between 2 types of silicon (Si) substrate those are Czochralski silicon (CZ) and floating zone silicon (FZ). There are 3 conditions to experiment that are undoped, platinum (Pt) doped and X-ray irradiated on Pt doped each Si substrate. Dark current and photocurrent are considerable parameters of photodetectors were investigated. The effect of X-ray irradiated to dark current is discrepant between CZ-Si and FZ-Si due to the contradiction of quantity defect atoms in each silicon substrate. In case of CZ-Si substrate dark current from the X-ray irradiated on Pt doped condition decreased when compared with the Pt doped condition. While the photocurrent increased to 2.7 times when compared with the same condition. Likewise in FZ-Si the dark current of CZ-Si substrate from the X-ray irradiated on Pt doped condition decreased when compared with the Pt doped condition and Photocurrent decreased to 1.4 times when compared with the same condition. The experimental results indicate the advantage of X-ray irradiation to photodetectors technology.