Growth of Bi doped cadmium zinc telluride single crystals by Bridgman oscillation method and its structural, optical, and electrical analyses

Abstract

The II-VI compound semiconductor cadmium zinc telluride ͑CZT͒ is very useful for room temperature radiation detection applications. In the present research, we have successfully grown Bi doped CZT single crystals with two different zinc concentrations ͑8 and 14 at. %͒ by the Bridgman oscillation method, in which one experiment has been carried out with a platinum ͑Pt͒ tube as the ampoule support. Pt also acts as a cold finger and reduces the growth velocity and enhances crystalline perfection. The grown single crystals have been studied with different analysis methods. The stoichiometry was confirmed by energy dispersive by x-ray and inductively coupled plasma mass spectroscopy analyses and it was found there is no incorporation of impurities in the grown crystal. The presence of Cd and Te vacancies was determined by cathodoluminescence studies. Electrical properties were assessed by I-V analysis and indicated higher resistive value ͑8.53 ϫ 10 8 ⍀ cm͒ for the crystal grown with higher zinc concentration ͑with Cd excess͒ compare to the other ͑3.71ϫ 10 5 ⍀ cm͒.

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

“…Cadmium zinc telluride (CdZnTe or CZT), a p-type semiconductor have recently gained much attention in the key detector technologies. The main attractive aspect of CZT crystals are (i) wide band gap (~1.68 eV) which is necessary for room temperature operation, (ii) a large photon absorption cross section (∼10 4 cm 2 /g for 1 keV photon energy; for photon energy <50 keV the absorption efficiency is >95%) for efficient conversion of optical energy in to electrical energy, and (iii) high resistivity (10 10 Ω.cm) to minimize the noise due to limiting the leakage current 1 – 5 . 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.…”

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

“…In earlier eras, various kinds of research and development have been done on CdZnTe (CZT) and its related compounds to achieve a good quality RT X-ray and γ-ray detector-grade single crystals that also can be applied in key applications. − The single crystals of CZT have been grown by different techniques, such as high-pressure vertical Bridgman, modified vertical Bridgman (MVB) technique, traveling heater method, , electrodynamic gradient freeze (EDG) furnace, vapor growth, and oscillatory Bridgman technique. , The analysis on grown CZT crystal shows that the crystals possess grain boundaries and other imperfections like: great Te inclusions, twin, and dislocations that makes limited use of CZT. ,− Among all these technique vertical gradient freezing (VGF) − is found to have better results in terms of good quality with less defects crystals for detection applications. The single crystals of CZT with different dopants such as, Bi, In, Ti, Pb, etc., were grown by oscillatory Bridgman technique, high-pressure, modified and vertical Bridgman methods. − It is well-known in the literature that CZT:In is a key artistic material for nuclear radiation detection at RT. However, there is no/least report available for In-doped CZT in which the correlation between growth, optical, excellent quality and strength, etc.…”

“…4,13−17 Among all these technique vertical gradient freezing (VGF) 18−21 is found to have better results in terms of good quality with less defects crystals for detection applications. The single crystals of CZT with different dopants such as, Bi, In, Ti, Pb, etc., were grown by oscillatory Bridgman technique, 22 highpressure, modified and vertical Bridgman methods. 23−28 It is well-known in the literature that CZT:In is a key artistic material for nuclear radiation detection at RT.…”

Melt growth and post‐grown annealing of semiinsulating (CdZn)Te by vertical gradient freeze method

“…CZT crystals with good spectroscopic performance are grown by Vertical Bridgman Method in IMEM Parma (Italy) [7]. Bridgman oscillating method and Vertical gradient freze method have been used for growth of semiinsulating CdZnTe by Universidad Autonoma de Madrid (Spain) [8]. Detector grade CZT crystals were<?pgbrk fill?> prepared by Vertical Bridgman Electro‐Dynamic Gradient (EDG) Freeze method in Washington State University [9].…”