Amorphous silicon ionizing particle detectors

This patent describes a particle detector having a body portion for detecting high energy ionizing particles moving in a path toward the detector where, upon penetration into the detector body portion, form electron-hole pairs. It comprises: a substrate, first electrode means formed on the substrate, an a-Si:H film deposited on the first electrode, the a-Si:H film comprises three monolithic, contiguous regions consecutively comprising an a-Si region doped to be a first conductivity type, an intrinsic region of a-Si and an a-Si region doped to be a second conductivity type, second electrode means formed over the a-Si:H film, means to increase the sensitivity to a level sufficient to detect single ionizing particles as they individually impact the detector body portion by increasing the collection efficiency of the a-Si:H film intrinsic region to have a low trap density below 1 x 1016 cm-3 ev -1 with a large film thickness above 1 μ and operative at voltages above 50 volts per μ, and means to collect the electron-hole pairs and indicate the number and energy level of the ionizing particles