Carrier recombination centers related with iron complexes inp‐type silicon are studied by microwave and light‐induced absorption techniques. Both thermal‐ and photoactivation are used to decompose iron–boron pairs and to study the impact on the recombination lifetime. Due to photodissociation of iron–boron pairs the lifetime increases for high level injection. Efficient recombination occurs via an acceptor level atEc−0.29 eV as derived from the temperature dependence of carrier lifetime. ©1995 American Institute of Physics.