Dynamic photoluminescence lifetime imaging for injectiondependent lifetime measurements

Abstract

We investigate the impact of an injection-dependent carrier lifetime in crystalline silicon on dynamic photoluminescence lifetime imaging (dynamic PLI). Although the dynamic lifetime approach is a technique that evaluates the time-dependence of a quantity proportional to the excess carrier density, it is only weakly influenced by the injection-level dependence of the lifetime. The reason for the little impact is the fact that the evaluation of dynamic PLI measurements does not only involve the decay of the carrier density, as it is common for photoconductance decay measurements, but also the increase of the carrier density directly after switching on the excitation source. In this contribution, we present injection-dependent lifetime measurements that are acquired with the camera-based dynamic PLI technique. We find that the deviation of the actual steady-state carrier lifetime from the lifetime obtained with dynamic PLI is less than 20 % for a wide range of measurement conditions.