This chapter deals with the variations of transient optoelectronic methods that are mostly performed on solar-cell devices and do not always require special device structures like the time-of-flight (TOF) technique. It also discusses the combination of charge extraction (CE) and transient photovoltage (TPV) measurements, which is frequently used to study charge carrier recombination in organic and nanoparticle solar cells. CE measurements can be used to determine the average excess charge density at a given voltage and illumination condition. This information can then be used to make conclusions regarding the density of states and the reaction order of the main nongeminate recombination process. Charge extraction with linearly increased voltage (CELIV) is a transient CE technique which can also determine the charge carrier density and charge carrier mobility simultaneously. Time-delayed collection field (TDCF) method, fast CE technique, is mainly the yield of the extracted charge carriers in dependence on laser intensity, delay time, and applied voltage.