The Challenge of Measuring Charge Carrier Lifetimes
Charge carrier lifetime is one of the most sensitive indicators of semiconductor material quality. It reflects recombination processes, defect densities, and transport properties that directly influence device performance.
However, these dynamics often span several orders of magnitude in time. Capturing both fast recombination processes and slower decay mechanisms requires measurement techniques that combine high temporal resolution with high sensitivity. Conventional steady-state methods often cannot resolve these dynamics in sufficient detail.
Time-Resolved Photoluminescence with TCSPC
Time-resolved photoluminescence (TRPL) combined with time-correlated single photon counting (TCSPC) provides a direct way to measure charge carrier dynamics across a wide temporal range.
Using pulsed laser excitation and single-photon detectors, luminescence lifetimes from tens of picoseconds to hundreds of microseconds can be resolved. Spectrally resolved detection further allows correlations between lifetime behavior and material-specific band gap transitions, which is particularly valuable for multi-component semiconductor systems.
The technique can also be integrated with spectrometer or microscope configurations, enabling both spectral analysis and spatially resolved mapping of carrier diffusion and material inhomogeneities.
