Textured α-HgI2 ceramics for sensitive X-ray detection.

In the prospect of manufacturing ionizing radiation detectors, dense ceramics of α-HgI 2 with a strong preferred orientation were elaborated. X-ray diffraction showed that most crystallites exhibited their crystal c-axis perpendicular to the ceramic plane, which should be favorable for optimum electrical transport properties. Dark current densities about 2 nA mm −2 (under 0.2 V μm −1 bias) were measured and were shown to arise mostly from the release of carriers from trap defects (Poole–Frenkel emission). The X-ray sensitivity ≈1600 nC mGy −1 cm −2 and the μτ value ≈ 3 × 10 − 5 cm 2 V −1 were comparable to those of other forms of polycrystalline HgI 2 . The HgI 2 ceramics also exhibited a perfectly linear response as a function of the X-ray dose. [ABSTRACT FROM AUTHOR]