Charge carrier dynamics describes the generation, transport, and recombination of electrons and holes—the mobile charge carriers—in a semiconductor following an external excitation such as photon absorption or electrical injection ^[1]. After generation, excess carriers drift under internal electric fields and diffuse down concentration gradients, with mobilities and diffusion coefficients linked by the Einstein relation, until they are lost through recombination, quantified by the minority-carrier lifetime and the associated diffusion length ^[2]. Recombination may be radiative, non-radiative through trap states (Shockley–Read–Hall), or via Auger three-body processes, each characterized by a distinct rate and time scale ^[3]. In photoexcited materials, the temporal evolution of excess populations is commonly described by rate equations linking generation, drift, diffusion, and recombination, while transient optical probes follow the decay of photoluminescence or photoconductivity. The dynamic quantities—lifetimes, mobilities, diffusion lengths, and internal quantum yields—determine how efficiently photogenerated carriers are collected and therefore set the performance of photovoltaic, photoconductive, and other semiconductor devices ^[4].