time-resolved cathodoluminescence

**Time-Resolved CL** is a **cathodoluminescence technique that measures the temporal decay of luminescence after pulsed electron excitation** — revealing carrier lifetimes, recombination dynamics, and defect kinetics with nanoscale spatial resolution. **How Does Time-Resolved CL Work?** - **Pulsed Excitation**: Beam blanker or pulsed electron source creates short excitation pulses (ps-ns). - **Time-Correlated Detection**: Single-photon detectors with time-tagging measure photon arrival times. - **Decay Curves**: Build luminescence decay curves at each pixel -> fit exponential decay times. - **Lifetime Maps**: Map carrier recombination lifetime across the sample. **Why It Matters** - **Carrier Lifetime**: Maps minority carrier lifetime with nanoscale resolution — impossible with optical techniques. - **Defects**: Non-radiative defects reduce lifetime locally — time-resolved CL maps defect activity. - **Quantum Structures**: Measures exciton dynamics in quantum dots and wells at individual nanostructure level. **Time-Resolved CL** is **watching luminescence die** — measuring how quickly carriers recombine to map defect activity and dynamics at the nanoscale.