Study of tellurium precipitates in CdTe crystals

Abstract

The effect of tellurium precipitates was studied in medium resistivity (103–106 Ω cm) undoped and Cl-doped CdTe using differential scanning calorimetry (DSC) and mid-infrared spectroscopy and the results were correlated with near-infrared microscopy photographs. When present in a significant quantity (∼0.25 wt %), we show that Te precipitates are detectable using DSC measurements. In the mid-infrared, the contribution of the absorption by free-carriers is negligible, and therefore, the effect of the Te precipitates in these crystals can be considered uncoupled from the effects of Cd vacancies.

Microstructural, optical and electrical properties of Cl-doped CdTe single crystals

“…. Similar result was also obtained by Jayatirtha et al [14]. However, it should be mentioned that the exact mechanisms underlying the participation of chlorine in the improvement of CdTe morphology are not clearly understood, what is also mentioned in the literature [9] and references therein, and the subject is currently under further investigations.…”

“…In this connection, Cl doping for annihilating all these point defects (i.e. Cd-vacancies and Te inclusions) can be an effective way to obtain semi-insulating (above 10 9 Ω·cm) high-quality CdTe material [2,8,9,13,14].…”

Improvement of composition of CdTe thin films during heat treatment in the presence of CdCl2

“…In the c-and X-ray detectors research work based on insulating and semi-insulating CdTe, it is well known that Te precipitation is common in CdTe material, irrespective of the growth technique [22][23][24][25][26]. It is also known that treatment similar to CdCl 2 , removes these precipitated Te [27].…”

Morphology evolution of micron-scale secondary phases in CdZnTe crystals grown by vertical Bridgman method

“…1 shows typical IR images for CZT samples grown under Te-rich conditions. The resulting high-contrast IR images were obtained due to the strong IR absorption of Te, corresponding to its relatively narrow band gap (with the value of 0.33 eV [18]). In these images the distinct dark areas are associated with the presence of Te-rich SP particles in the CZT wafer.…”