A system and method for characterizing electronic properties of a semiconductor sample includes illuminating the surface of the semiconductor sample with a pulse of light, measuring a photoconductance decay in the semiconductor sample after the cessation of the first pulse of light, and analyzing the photoconductance decay. The electronic properties include properties associated with at least one of the bulk of the semiconductor sample and the surface of the semiconductor sample. The pulse of light has a predetermined duration and photon energy higher than energy gap of the semiconductor. The analyzing step determines a first component of the photoconductance decay substantially associated with point imperfections in the semiconductor sample and at least one second component of the photoconductance decay substantially associated with extended imperfections in the semiconductor sample.