V. Carcelén

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

The II-VI compound semiconductor cadmium zinc telluride (CZT) 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 (Pt) 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 (8.53×108 Ω cm) for the crystal grown with higher zinc concentration (wit...

Relationship between the cathodoluminescence emission and resistivity in In doped CdZnTe crystals

Cadmium zinc telluride, CdZnTe, bulk single crystals doped with 1019 at./cm3 of indium in the initial melt were grown by vertical Bridgman technique. The samples were investigated by energy dispersive spectroscopy, cathodoluminiscence (CL), and current-voltage behavior at room temperature. The results shows that Cd and Te vacancy concentration depend on the indium and zinc concentrations. CL measurements indicate a relationship between radiative centers associated to Cd and Te vacancies and resistivity values.

Development of CdZnTe doped with Bi for gamma radiation detection

Bulk CZT crystals doped with Bi (1 x 10(19) at/cm(3)) have been grown by the Oscillatory Bridgman method, the growth velocity and the zinc concentration profile being improved by the insertion of a Pt tube acting as a cold finger. The stoichiometric uniformity was examined by energy dispersive X-ray analysis, and the zinc concentration was confirmed by inductively coupled plasma mass spectroscopy and cathodoluminescence measurements. The resistivity value was in the range of 8 x 10(8) Omega cm , being smaller for the passivated sample, which at the same time had counter device properties.