Analysis on the sharpness of optical sensitivity for amorphous selenium sensors with carbon nanotubes

Amorphous selenium (a-Se) has been studied as an X-ray image detector and low-intensity light camera detector because of its superior avalanche multiplication characteristics. Various types of electron emitters are used for the a-Se photo detectors. Carbon nanotubes (CNTs) emitters are one of the promising electron emitters because of their superior electrical properties and chemical stability. CNTs grown using the resist-assisted patterning (RAP) process are suitable because the pattern size and CNTs length are easily controllable. From I-V-L measurement, the photo-induced voltage drop (ΔVph) in the a-Se layer was determined to be 30 V and 60 V under an illumination of 3.68 lx and 988 lx, respectively. Also, we defined the sharpness (S) of the photo-sensitivity as a function of applied voltage to analyze a-Se based image sensing device. Here we report on the optical switching mechanism of a-Se targets using CNTs electron emitters.