Halogen-doped Cadmium Telluride for Detection of Gamma Rays

Abstract

DURING the past ten years the development of semiconductors for the detection of gamma rays has been proceeding at an accelerating pace, so that lithium drifted silicon detectors, as well as lithium drifted germanium detectors and undrifted germanium detector materials, are now commercially available. These materials have two important shortcomings: first, they must be operated at liquid nitrogen temperatures if they are to give their best performance (although Si is useful up to +40° C); and second, silicon in particular has a low absorption cross section for gamma rays because of its low atomic weight. So the use of heavier compound semiconductors with larger energy gaps, in particular CdTe, has been of substantial interest in the development of solid state nuclear detectors1,2.