Thismini-reviewgivesasimpleoverviewoftheworkingsoforganicphotovoltaic(OPV)devices,thewayinwhichchargetransfer occurs through the active layers, and then introduces how photo-induced charge carrier extraction by linearly increasing voltage (photo-CELIV)andtimeofflight(TOF)techniquescanbeemployedtogivecomprehensiveindicationsofchargecarrier mobility, density and recombination in OPVs. It is shown how photo-CELIV and TOFcharacterizations, using extraction current transients, can give an understanding of degradation mechanisms through observation of the trapping of charge carriers and bimolecular recombination. Examples of deployment and the interpretation of the results are given. It is hoped that this brief introduction will serve as a stepping stone into more in-depth papers and books and encourage wider use of photo-CELIV and TOFtechnologieswhichcanbeemployedwithwholedevices. ©2016SocietyofChemicalIndustry