Microscopic charge carrier lifetime in silicon from a transient approach

Abstract

We present an experimental approach to determine the charge carrier lifetime in silicon based on the measured transient decay of the emitted photoluminescence intensity, requiring only a crystal volume of 50 μm in diameter. This becomes feasible by a combination of the time correlated single photon counting technique and confocal microscopy. Using combined pulsed and pulse train laser excitation, we obtain a self-consistent charge carrier lifetime in a high dynamic range from 100 ns to ms and an injection range from 1010 cm−3 to high injection densities. An iterative data evaluation routine incorporates all effects induced by the spatially non-homogeneous charge carrier generation.