Performance of a-Six: C1-x:H Schottky barrier and pin diodes used as position sensitive detectors

Position sensitive detectors (PSD) using hydrogenated amorphous silicon as the active layer have been widely proposed either with the p-i-n or the Schottky structure. In this case, the devices are tailored to respond to light in the range 620-650 nm. Little is known about the use of silicon carbide active layers in such devices, which is important when the detected light is in the blue region of the light spectrum. In this paper we present for the first time the electro-optical properties of the a-Si_x:C_1-x:H/Pd and p-i_c-n PSD, using a-Si_x:C_1-x:H layers deposited by plasma enhanced chemical vapour deposition (PECVD). These sensors are able to distinguish the wavelength of the impinging visible radiation (from red to blue light). In addition, the sensors respond to light intensities as lower as 1 × 10^-6 W cm^-2 with a resolution better than 0.04 mm and a linearity between ±0.12% and ±0.8%.