New progress in large-size CZT single-crystal growth for nuclear radiation detectors

Large-size CdZnTe (Zn=10%) radiation detector materials and device performance

“…Using a MVB technique, Yinnel has successfully achieved 2-inch diameter CZT (Zn=10%) singlecrystal volumes of 50 cm 3 [5] and 3-inch diameter CZT (Zn=10%) single-crystal volumes of 100-300 cm 3 respectively [1][2][3]. Figure 1 shows a typical 3-inch diameter CZT ingot with a singlecrystal volume of about 300 cm 3 .…”

“…Figure 1 shows a typical 3-inch diameter CZT ingot with a singlecrystal volume of about 300 cm 3 . Figure 2 shows a typical 2-inch CZT ingot with a single-crystal volume of over 50 cm 3 . The bottom photo in Figure 2 shows a section of this 2-inch diameter, 80-mm length ingot.…”

“…According to our studies [1][2][3][4] and [6], indium is the "best" dopant (8+ purity) for compensation of the deep and shallow trapping centers in our CZT materials. Most of the traps act as acceptors, such as Cd vacancies, Li, Na, Fe, Co, Cu and O, and they make the resistivity of undoped material p-type [3].…”

“…The indium dopant increased the CZT bulk electrical resistivity up to 1-3 x 10 11 cm [4]. Mobility-lifetime products for electrons and holes, (e) and (h), were measured to be as large as 1.8x10 -2 cm 2 /v @ In=12 ppm and 7.0x10 -4 cm 2 /v @ 15 ppm [2][3]. Reproducibility of the CZT ingots with high (e), (h), electrical resistivity, homogeneity, and high detector performance was achieved for a significant fraction of the volume of each ingot.…”

“…Three-inch diameter CZT ingots have been routinely grown from which single-crystal volumes as large as 300 cm 3 were mined [1][2][3]. Indium was used as the Group-III dopant to control the electrical resistivity [1][2][3][4][5].…”