CdTe doped with chlorine is used as a radiation detector for x-rays, gamma rays, beta particles and alpha particles. CdTe can operate at room temperature allowing the construction of compact detectors for a wide variety of applications in nuclear spectroscopy. The properties that make CdTe superior for the realization of high performance gamma- and x-ray detectors are high atomic number, large bandgap and high electron mobility ~1100 cm2/V·s, which result in high intrinsic μτ (mobility-lifetime) product and therefore high degree of charge collection and excellent spectral resolution. Due to the poor charge transport properties of holes, ~100 cm2/V·s, single-carrier-sensing detector geometries are used to produce high resolution spectroscopy; these include coplanar grids, Frisch-collar detectors and small pixel detectors.