Single carrier-type solid-state radiation detector device

摘要

A three terminal solid-state ionizing radiation detector (10) includes a first layer (18) of a substantially intrinsic Group II-VI compound semiconductor material, such as CdZnTe. The first layer is responsive to incident ionizing radiation for generating electron-hole pairs. The detector further includes a second layer (24) of Group II-VI compound semiconductor material and a third layer (20) of Group II-VI compound semiconductor material that is interposed between first surfaces of the first layer and the second layer. The third layer functions as a grid layer. A first electrical contact (12, 17) is coupled to a second surface of the first layer, a second electrical contact (29, 30) is coupled to a second surface of the second layer, and a third electrical contact (22) is coupled to the third layer for connecting the detector to an external circuit that establishes an electric field across the detector. The electric field causes holes to drift away from the grid layer towards the first contact while electrons drift towards and through the grid layer, through the second layer, and towards the second contact for generating a detectable output signal pulse. Because of the presence of the grid layer only the electrons contribute to the output pulse. The grid layer has a conductivity type such that electrons are a minority charge carrier within the grid layer.