Single carrier-type solid-state radiation detector device

A three terminal solid-state ionizing radiation detector, comprising:

• a first layer comprised of a substantially intrinsic Group II-VI compound semiconductor material, said first layer being responsive to incident ionizing radiation for generating electron-hole pairs;
• a second layer comprised of Group II-VI compound semiconductor material;
• a third layer comprised of Group II-VI compound semiconductor material that is interposed between a first surface of said first layer and a first surface of said second layer;
• first electrical contact means coupled to a second surface of said first layer, second electrical contact means coupled to a second surface of said second layer, and third electrical contact means coupled to said third layer, said first, second and third contact means for coupling said detector to an external circuit that establishes an electric field across said detector such that holes drift away from said third layer towards said first contact means, and electrons drift towards and through said third layer, through said second layer and towards said second contact means for generating a detectable output signal;
• wherein said third layer has a conductivity type such that electrons are a minority charge carrier within said third layer and an energy bandgap such that an interface between said third layer and said first layer functions as a barrier to holes.

An array of ionizing radiation detectors, comprising:

• a first layer comprised of semiconductor material, said first layer being responsive to incident ionizing radiation for generating electron-hole pairs;
• a second layer comprised of semiconductor material;
• an electrode region interposed between a first surface of said first layer and a first surface of said second layer;
• first electrical contact means coupled to a second surface of said first layer, second electrical contact means coupled to a second surface of said second layer, and third electrical contact means coupled to said electrode region for connecting to an external circuit that establishes an electric field across the layers such that holes drift away from said electrode region towards said first contact means, and electrons drift towards and through said electrode region, through said second layer and towards said second contact means for generating a detectable output signal;
• wherein said second layer and said second electrical contact means are differentiated into a plurality of separate second layer portions and corresponding second electrical contact means portions each of which forms, in combination with an underlying portion of said electrode region and an underlying portion of said first layer, an ionizing radiation detector pixel.

A method for fabricating an array of ionizing radiation detectors, comprising the steps of:

• providing a first layer comprised of semiconductor material, the first layer being responsive to incident ionizing radiation for generating electron-hole pairs;
• forming an electrode region upon a first surface of the first layer;
• growing, upon the electrode region, a second layer comprised of semiconductor material;
• forming first electrical contact means upon a second surface of the first layer, second electrical contact means upon a second surface of the second layer, and third electrical contact means that is coupled to the electrode region for connecting to an external circuit that establishes an electric field across the layers;
• and
• differentiating the second layer and the second electrical contact means into a plurality of separate second layer portions and corresponding second electrical contact means portions each of which forms, in combination with an underlying portion of the electrode region and an underlying portion of the first layer, an ionizing radiation detector pixel.