This book provides an extensive review of the theory of transport and recombination properties in semiconductors. The emphasis is placed on electrical and optical techniques. There is a presentation of the latest experimental and theoretical techniques used to analyze minority-carrier lifetime. The relevant hardware and instrumentation are described. The newest techniques of lifetime mapping are presented. The issues are discussed relating to effects that mask carrier lifetime in certain device structures. The discrepancy between photoconductive and photoluminescence measurement results are analyzed.