Large Size Crystal Growth, Photoluminescence, Crystal Excellence, and Hardness Properties of In-Doped Cadmium Zinc Telluride

Abstract

In the current work, successful growth of an In-doped CdZnTe (InCZT) ingot with a bulk size of ∼8 cm long and 2.5 cm diameter was achieved through gradient freeze process. The whole crystal ingot was cut in six small ingots (1−6), and from these, we have selected pieces 1, 2, 4, and 6, which were again cut into ∼2 mm thickness portions (named 1-1, 1-2, 2-1, 2-2, 4-1, and 6-1) and polished for further characterization. The single phase and direction of growth was verified by X-ray diffraction analysis, which confirmed its growth along (111) plane. The excellence of the grown crystal was analyzed through high-resolution X-ray diffraction (HRXRD), which confirms that the grown crystals is quite perfect and may be used in device fabrications. The Vickers microhardness indentation studies and load dependence studies on different parts of 1-1, 1-2, 2-1, 2-2, 4-1, and 6-1 InCZT crystals are carried at different loads from 0.098 to 0.49 N. Examination of these samples reveals RISE behavior and it is explained by several models of Mayer's law, Hays−Kendall's tactic, and proportional resistance model. Also fracture toughness, brittleness index, yield strength, and elastic stiffness values are measured from indentation studies and found very much correlated with HRXRD analysis.

High-performance visible light photodetectors based on inorganic CZT and InCZT single crystals

“…7 . The low value of β attributed to long-lived charge traps due to higher defects density present in both semiconductors mainly in InCZT 6 , 12 . The CZT crystal has relatively higher number of native defects due to Cd and Te vacancies.…”

“…4(b) . The higher value of β for CZT is due to better crystalline quality and a small defect in CZT compare to InCZT crystals 6 , 12 . The In-doping introduce additional defects in the crystal lattice of CZT and hence InCZT crystal have higher density of trapped electrons, this leads to a higher EQE of InCZT based devices as compared to CZT.…”

“…The cut and polished rectangular specimens from grown crystals 6 , 12 were prepared and subjected to X-ray diffractometer (XRD) to confirm the growth direction. A typical photodetector consists of a semiconductor as a channel, with two ohmic contacts affixed to opposite ends of the channel as depicted in Fig.…”

“…These specific properties allow its applications in a wide range of devices such as X-ray or γ-ray detector, nuclear spectroscopy, medical imaging, radiation sensors, photorefractive, etc. 6 – 10 . Due to such venerable applications of CZT crystals in detector technology, it has already started to replace the existing X-ray and γ-ray detectors as well as other semiconductors detectors.…”

Study of Hardness of Superhard Crystals by Topological Indices

“…where n i is the position in the form of a number of the ith atom in the unit cell, Z i is the valence electron number of the ith atom crediting to the covalent bond, and V is the volume of the unit cell. More results on the hardness (various definitions of hardness) study of crystals can be referred to Suzuki et al [4], Armstrong et al [5], Mamun et al [6], Shkir et al [7], and Palatnikov et al [8]. Now, if we talk about the unit crystals studied in this article, then the first one is BC 2 , and by the first-principles computations, BC 2 was predicted originally from (a kind of tetragonal phase) the cubic diamond structure.…”