Characterisation of vapour grown CdZnTe crystals using synchrotron X-ray topography

Journal of Crystal Growth

et al. 2016

Wegrew Cd 1-x Mn x Te crystals witha nominal Mn concentrationof 5% by the vertical Bridgman growth technique. The structural quality of the crystal was evaluated by white beam X-ray topography in the National Synchrotron Light Source (NSLS) facility at Brookhaven National Laboratory (BNL). We observed that the crystal was free from a sub-grain boundary network, as revealed by X-ray topography and verified by our etching study. The concentration of the secondary phases, averaged over the entire ingot, was 2-3 times lower than in conventional Bridgman grown cadmium zinc telluride (CZT)crystals.

Section: Resultssupporting

confidence: 52%

Growth and characterization of CdMnTe by the vertical Bridgman technique

Journal of Crystal Growth

et al. 2016

“…It is to be noted that no lattice distortion was observed near the periphery of the wafer touching the ampoule wall, as indicated by the blue arrow, depicting stress-free ampoule wall contact. In general, ampoule walls are the common source of introducing strains 30,31 , and severe lattice distortions near the periphery of the ingots have been observed for CdTe-based materials 30,31 , even for contactless vapor grown CdZnTe 32 . The material is free from any thermal stress as evident from the undistorted twins in the X-ray topographic image as indicated by the green arrows in Fig.…”

Section: Resultsmentioning

confidence: 99%

Role of selenium addition to CdZnTe matrix for room-temperature radiation detector applications

et al. 2019

Sci Rep

Because of its ideal band gap, high density and high electron mobility-lifetime product, cadmium zinc telluride (CdZnTe or CZT) is currently the best room-temperature compound-semiconductor X- and gamma-ray detector material. However, because of its innate poor thermo-physical properties and above unity segregation coefficient for Zn, the wide spread deployment of this material in large-volume CZT detectors is still limited by the high production cost. The underlying reason for the low yield of high-quality material is that CZT suffers from three major detrimental defects: compositional inhomogeneity, high concentrations of dislocation walls/sub-grain boundary networks and high concentrations of Te inclusions/precipitates. To mitigate all these disadvantages, we report for the first time the effects of the addition of selenium to the CZT matrix. The addition of Se was found to be very effective in arresting the formation of sub-grain boundaries and its networks, significantly reducing Zn segregation, improving compositional homogeneity and resulting in much lower concentrations of Te inclusions/precipitates. Growth of the new quaternary crystal Cd1−xZnxTe1−ySey (CZTS) by the Traveling Heater Method (THM) is reported in this paper. We have demonstrated the production of much higher yield according to its compositional homogeneity, with substantially lower sub-grain boundaries and their network, and a lower concentration of Te inclusions/precipitates.

“…Severe lattice distortion resulting from strain introduced by the crucible wall is very common for CdTe and CZT [26][27][28]. Lattice distortions demonstrated by the streaky nature of the X-ray topographic images near the periphery of the wafers were also observed for contact-less vapor grown CdTe and CZT [27,28].…”

Section: Resultsmentioning

confidence: 93%

X-ray topographic study of Bridgman-grown CdZnTeSe

Journal of Crystal Growth

et al. 2020

We have characterized the structural quality of Cd0.9Zn0.1Te0.93Se0.07 ingot grown by the vertical Bridgman growth technique. The structural quality of Cd0.9Zn0.1Te0.93Se0.07 ingot along the length was investigated via X-ray topography in the reflection mode using a white beam synchrotron radiation source. The X-ray topography data revealed the presence of very few sub grain boundaries and no sub-grain boundary network for the CdZnTeSe samples used in this study.