Time-resolved photoluminescence imaging with electronic shuttering using an image intensifier unit

In contrast to traditional steady-state photoluminescence imaging (PLI), time-resolved photoluminescence imaging (TR-PLI) allows for a calibration-free measurement of the effective transient minority charge carrier lifetime τeffτeff in a silicon sample. For transient photoluminescence measurements, the illumination source as well as the camera signal have to be modulated on a time-scale in the order of τeffτeff. Different approaches for camera signal modulation have been presented, including the use of a complementary metal-oxide-semiconductor (CMOS) camera or a rotating shutter wheel. In this work, the use of an InGaAs-based image intensifier unit as a fast optical shutter for TR-PLI was evaluated. Due to the fast switching times of the image intensifier, effective lifetimes down to 1/50 of the modulation period could be resolved reliably. Measurements under different illumination conditions allow for an injection-dependant analysis of τeffτeff and comparison to photoconductance decay measurements.

► An ICCD camera was used for time-resolved photoluminescence imaging of Si wafers.
► The technique provides a fast mapping of absolute excess charge carrier lifetimes.
► Carrier lifetimes down to 1/50 of the excitation frequency could be resolved.
► Injection-dependant lifetime measurement at each point of the sample is possible.