Patent ID: 7038242

Claim:
An imaging arrangement comprising: a substrate; and an array of amorphous semiconductor bipolar phototransistors on said substrate, said bipolar phototransistors being open base devices, each said bipolar phototransistor including a plurality of amorphous semiconductor layers, said plurality of amorphous semiconductor layers including at least one p-type layer and at least one n-type layer, each said bipolar phototransistor having an electrically open amorphous semiconductor base layer free from external control that is configured to provide base-hole current injection for enabling bipolar gain for photocurrent through the phototransistor, wherein the photocurrent represents the light intensity received by said phototransistor; wherein each said bipolar phototransistor includes an intrinsic collector layer and wherein at least a portion of said electrically open amorphous semiconductor base layer resides between said substrate and said intrinsic collector layer, said amorphous semiconductor base lever being amorphous silicon.