OPTICAL ACTIVE PROCESS OF HIGHER-ORDER BANDS IN FAST-NEUTRON IRRADIATED SILICON

Using Fourier transform infrared absorption measurement with excitatio n at low temperatures, we have investigated the optical active process involving higher order bands (HOB) in fast neutron irradiated float-z one silicon. It is found experimentally that the photo''citation and d ecay process of the HOB as well as the saturation value of the absorpt ion intensity are in good agreement with the predictions of the macros copic barrier model for the slow relaxation of photoexcited carriers c aused mainly by defect clusters.