Growth of detector-grade CZT by Traveling Heater Method (THM): An advancement

In this present work we report the growth of Cd0.9Zn0.1Te doped with In by a modified THM technique. It has been demonstrated that by controlling the microscopically flat growth interface, the size distribution and concentration can be drastically reduced in the as-grown ingots. This results in as-grown detector-grade CZT by the THM technique. The three-dimensional size distribution and concentrations of Te inclusions/precipitations were studied. The size distributions of the Te precipitations/inclusions were observed to be below the 10-μm range with the total concentration less than 10 cm. The relatively low value of Te inclusions/precipitations results in excellent charge transport properties of our as-grown samples. The (μτ)e values for different as-grown samples varied between 6-20 x10 cm/V. The as-grown samples also showed fairly good detector response with resolution of ~1.5%, 2.7% and about 3.8% at 662 keV for quasi-hemispherical geometry for detector volumes of 0.18 cm, 1 cm and 4.2 cm, respectively.