Post-growth thermal annealing study of CdZnTe for developing room-temperature X-ray and gamma-ray detectors

Post-growth annealing of Bridgman-grown CdZnTe and CdMnTe crystals for room-temperature nuclear radiation detectors

“…In previous experiments we recorded that many of the small-size Te inclusions were eliminated after annealing in a Cd vapor at 923 K ($ 650 1C) for 24 h while the larger inclusions remained, and observed size-reduction for larger inclusions in two cases: 1) annealing at higher temperature of 1100 K ($ 827 1C) for a shorter time of 60 min, and 2) a two-cycle annealing at 1100 K for 15 min per cycle [12]. The results in the present work show that both elimination of small-size Te inclusions and the size-reduction of large Te inclusions in CZT wafers can also be achieved at lower temperature of 510 1C and longer time of 60 h (see Table 1 and Fig.…”

“…The second thermal-annealing approach involves inducing movement of the Te inclusions under temperature gradients and their accumulation at the sample's high-temperature side, leaving the higher-quality regions of the crystal with fewer smaller particles. In previous experiments we recorded that annealing in a Cd vapor effectively removes Te inclusions from CZT, and there was migration of Te inclusions for annealing in a temperature-gradient field [12]. While many of the small-size Te inclusions were eliminated after annealing in a Cd vapor at 923 K for 24 h, the larger inclusions remained; and the size-reduction for larger inclusions become possible in two cases: 1) annealing at higher temperature of 1100 K for a shorter time of 60 min, and 2) a two-cycle annealing at 1100 K for 15 min per cycle [12].…”

“…In previous experiments we recorded that annealing in a Cd vapor effectively removes Te inclusions from CZT, and there was migration of Te inclusions for annealing in a temperature-gradient field [12]. While many of the small-size Te inclusions were eliminated after annealing in a Cd vapor at 923 K for 24 h, the larger inclusions remained; and the size-reduction for larger inclusions become possible in two cases: 1) annealing at higher temperature of 1100 K for a shorter time of 60 min, and 2) a two-cycle annealing at 1100 K for 15 min per cycle [12]. It has been reported that annealing under a Cd vapor pressure at high temperatures above $1170 K generates a large quantity of irregular Cd inclusions in the CZT matrix [13].…”

Gamma‐ray tolerance of CdS/CdTe photodiodes for radiation tolerant compact image sensor with field emitter array

“…Furthermore, it is possible to fabricate small FEA image sensors on a scale comparable to that of CMOS and CCD sensors. In addition, because CdTe is used in radiation detectors, we also expect CdTe diodes to have a high tolerance to radiation [5][6][7][8][9]. CdTe is also used in high efficiency solar cells, and has a bandgap of approximately 1.5 eV [10][11][12][13][14][15][16].…”

Deposition of Cl‐doped CdTe polycrystalline films by close‐spaced sublimation

“…1 Introduction CdTe and Cd 1-x Zn x Te (CZT) have attracted attention as room temperature X-ray and γ-ray detectors, because they have an inherently high stopping power of X-ray and γ-ray, a good carrier-transport property, and relatively wide band-gap energy [1][2][3][4][5]. However, it would be difficult to apply single-crystal CdTe and CZT detectors to large-area flat panel X-ray detectors.…”