Extrinsic silicon photodetector characterization

A gallium doped silicon (Si:Ga) extrinsic photoconductive detector was tested for sensitivity and quickness of response. The developmental goal for this detector material was high speed operation without compromised detectivity (D*). The high speed, p-type infrared photoconductor, with photoconductive gain less than unity, was tested at 10.5 microm to determine an experimental value for the detectivity-bandwidth product of D*f* = 3.69 x 10(18)cm-Hz(3/2)/W. Subsequently a theoretical model taking into account the optical absorption profile and majority-carrier-transport processes within the detector was developed. It agreed with experimental data and corroborated the theory.