Figure 5: Minority carrier lifetimes in CuInSe2 and GaInAs as a function of threading dislocation densities (TDD). A threshold density of 8.4 × 106 cm−2 for CuInSe2 can be observed based on the reduction of the lifetime by a factor of 2 (marked by light gray rectangle), whereas the threshold is closer to 2.6 × 104 cm−2 for electrons in GaInAs (marked by dark gray rectangle).