Semiconductor detectors typically identify gamma radiation sources. Semiconductor detectors using Cadmium Zinc Telluride (CZT) and High Purity Germanium (HPGe) can detect x-rays and gamma rays. HPGe detectors need to be cooled to reduce the thermal noise, while most of the other detectors can operate at room temperature. These detectors directly convert x-ray or gamma-ray photons into electrons. The radiation deposits energy at some point in the crystal lattice where it results in the generation of pairs of charge carriers. By application of an electric field, the charge carriers get swept to the cathode and anode of the device where they induce a current pulse that can be detected.