Metal-halide perovskites are highly attractive optoelectronic materials. Their charge dynamics are remarkably complex, with photodoping—arising from asymmetric charge trapping—playing a dominant role.[1] In this lecture, I will demonstrate how steady-state and time-resolved photoluminescence (PL) spectroscopies enable the rationalization of charge dynamics in perovskite samples and the development of a corresponding theoretical model.[1] New methodologies based on varying the pulse repetition rate and applying multiple excitation pulses to measure transient PL decays will be discussed. Furthermore, I will show how charge trapping induces memory effects in the PL response, forming the basis of an optical memristor, or memlumor—a luminescent memory element with a state-dependent PL quantum yield.[2] Perovskite-based memlumors exploit photodoping and photochemistry to encode volatile and non-volatile optical memory over timescales ranging from nanoseconds to days. Using a novel multi-pulse time-resolved PL technique, we demonstrate ultralow switching energies in the femtojoule range and sub-microsecond classification of binary optical pulse patterns, positioning memlumors as promising components for neuromorphic optical computing. [3][4]