Lifetime measurements in semiconductors by infrared absorption due to pulsed optical excitation

A new contactless technique for determination of excess carrier lifetime in semiconductors is demonstrated. The technique involves measuring the change in the transmitted intensity of a continuous probe beam (hν Eg). The technique has been applied to silicon samples having different doping densities. The measured lifetime values in the range of 0.5–200 μs on both n-type and p-type silicon samples by this new technique agree well with the values obtained by the traditional photoconductive decay method.