Proposal for a new room temperature X-ray detector-thallium lead iodide

Numerous compounds have been considered for room temperature semiconductor detector applications. Most of them however are difficult to obtain as crystals and to handle. TlPbI/sub 3/ is a promising candidate, because it forms rhombohedral crystals which do not have a structural phase transition between room temperature and their melting point. Its low vapour pressure facilitates the crystal growth and it has a low melting point (619 K), high Z, high density (6.6 g/cm/sup 3/), and a bandgap of 2.3 eV. X-ray photoconductivity measurements indicate that this material can be used in room temperature solid state detectors.