A contactless method for measuring the lifetimes of nonequilibrium charge carriers in semiconductors

摘要

A setup for measuring the lifetimes of nonequilibrium charge carriers in semiconductors is described. Its performance characteristics are as follows: the range of lifetime measurements is from 50 ns to 200 μs, the spatial resolution is 100 μs, and the operation speed is 1000 measurements per second. Excess carriers are generated by short laser pulses. An increment of the carrier concentration is detected by a change in the microwave-power absorption. A vacuumless cryostat is of an original design and is Simple and convenient in operation. A sample can be replaced in 1 mm. The high metrological characteristics of the setup are ensured by using a computer for data recording, an electron time-to-code converter, and a rapid positioning device.