High speed, ion bombarded InGaAs photoconductors

Studies of the performance of n-InGaAs photoconductive detectors before and after the introduction of recombination sites via ion bombardment are described. An empirical relation between speed of response and bombardment dose by Be ions is established for this material, demonstrating that the response time can be controllably reduced by more than two orders of magnitude below the few nanosecond time which is characteristic of undamaged devices. In this same radiation dose range only moderate mobility deterioration is observed. Greater than unity photoconductive gain is demonstrated for large size (15 μm) devices with a 1/e response time of 400 ps