Growth of large, high purity, low cost, uniform CdZnTe crystals by the “cold travelling heater method”

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

“…In order to evaluate our as-grown CZT crystals, we have investigated the size distribution and concentrations of Te inclusions/precipitations present in the bulk of the crystals. Figure 5a shows a typical 3D volumetric distribution of Te inclusions/precipitations over the volume of 1x1.5x3 mm 3 for CZT grown using our THM method. The total concentration of the Te inclusions/precipitations over the scanned volume was estimated to be 1.3x10 5 cm -3 and is comparable to the recently reported value for commercially available CZT samples [11].…”

“…The THM technique offers many advantages over melt-growth techniques. The main advantage is the fairly uniform Zn concentration along the growth direction [3,4]. The uniform Zn concentration is essential for good charge transport especially for thick detectors in addition to better yield.…”

Synthesis of ultra-high-purity CdTe ingots by the traveling heater method

“…This has a significant impact in reducing contamination from the crucible walls, typically made from high-purity quartz. 3 Indeed, the diffusion coefficients of a number of elements in quartz, including sodium, lithium, calcium, and potassium, increase rapidly with temperature, and become significant at temperatures reaching 1,000°C or more. • A low-pressure environment: The compounding of tellurium and cadmium to form CdTe is a highly exothermic process.…”

Fundamentals of the CdTe synthesis

“…According to the CTHM principle, a composite source material is constituted of a Cd rod of appropriate diameter surrounded by Te pieces and powder (Fig. 3) [11,12]. The movement of the solvent zone through this composite charge, at a temperature of ∼750-950 • C, induces the fractional and progressive synthesis of the compound in Te solution, its growth and purification.…”