We have studied the electrical properties of dislocations, stacking faults, and precipitates produced during 1200 °C aging of crucible‐grown silicon. The defects were examined by SEM in the charge collection mode, at temperatures from 77 to 300 °K. Undecorated Frank extrinsic stacking faults exhibit defect energy levels in the upper half of the gap (∼Ec−0.1 eV). The partial dislocations bounding these faults possess energy levels lower thanEc−0.3 eV. Finally, precipitates are observed to act as microplasma sites at low (T<300 °K) temperatures.