Abstract: PbO-based photoconductive X-ray imaging devices are disclosed in which the PbO photoconductive layer exhibits an amorphous crystal structure. According to selected embodiments, the amorphous PbO photoconductive layer may be formed by providing a substrate inside an evacuated evaporation chamber and evaporating lead oxide to deposit a photoconductive lead oxide layer onto the substrate, while subjecting the photoconductive layer to ion bombardment with oxygen ions having an ion energy between 25 and 100 eV. X-ray direct detection imaging devices formed from such amorphous PbO photoconductive layers are shown to exhibit image lag that is suitable for fluoroscopic imaging.

Abstract: PbO-based photoconductive X-ray imaging devices are disclosed in which the PbO photoconductive layer exhibits an amorphous crystal structure. According to selected embodiments, the amorphous PbO photoconductive layer may be formed by providing a substrate inside an evacuated evaporation chamber and evaporating lead oxide to deposit a photoconductive lead oxide layer onto the substrate, while subjecting the photoconductive layer to ion bombardment with oxygen ions having an ion energy between 25 and 100 eV. X-ray direct detection imaging devices formed from such amorphous PbO photoconductive layers are shown to exhibit image lag that is suitable for fluoroscopic imaging.

Abstract: The invention provides a new class of photoconductive materials and devices, and methods for obtaining high internal photoconductive gain. The devices include a semiconductor or material with an electronic band gap provided in a confined geometry and which exhibits multi-exciton generation (MEG) when illuminated with photons with energies above the threshold for MEG. Due to carrier-carrier Coulombic interactions, multi-excitons within the confined material efficiently recombine via Auger recombination, in which a carrier from one exciton is excited to a higher energy level relative to the band edge. Carriers excited by Auger recombination are subsequently trapped by trap states that capture carriers excited high above the band edge more efficiently than carriers near the band edge. Carriers trapped by the trap states allow for the collection and recirculation of untrapped carriers of opposite charge when used as a photoconductive device, producing high internal photoconductive gain.

Abstract: The invention provides a new class of photoconductive materials and devices, and methods for obtaining high internal photoconductive gain. The devices include a semiconductor or material with an electronic band gap provided in a confined geometry and which exhibits multi-exciton generation (MEG) when illuminated with photons with energies above the threshold for MEG. Due to carrier-carrier Coulombic interactions, multi-excitons within the confined material efficiently recombine via Auger recombination, in which a carrier from one exciton is excited to a higher energy level relative to the band edge. Carriers excited by Auger recombination are subsequently trapped by trap states that capture carriers excited high above the band edge more efficiently than carriers near the band edge. Carriers trapped by the trap states allow for the collection and recirculation of untrapped carriers of opposite charge when used as a photoconductive device, producing high internal photoconductive gain.