Charge extraction is the fundamental process by which photogenerated charge carriers (electrons and holes) are efficiently separated and transported from the active light-absorbing material to the respective electrodes in photovoltaic or other optoelectronic devices. This concept investigates the physical mechanisms governing charge transport across interfaces and within materials, focusing on minimizing recombination losses that hinder performance. Its significance lies in being a critical determinant of device efficiency, as effective charge extraction is necessary to convert absorbed photons into usable electrical current.