Revealing Te inclusions on VGF-grown CdZnTe crystals by using low energy argon ion irradiation: Influence of the substrate temperature
Abstract
Cd1-xZnxTe (CZT) crystals find interesting uses in a variety of detector-type applications. However, it is well known that the concentration and distribution of Te inclusions within a device are one of the major contributions to the degradation of CZT detectors. In addition, Te precipitates on the surface can also increase the leakage current, thereby deteriorating the device performance.
Our previous studies clearly revealed a pronounced effect when CZT surfaces were irradiated with Ar ions at room temperature. Even for small fluences, a removal of polishing scratches on the sample surfaces was observed. Correlated to this effect, an important enhancement in the luminescence intensity of the irradiated samples was observed. Te inclusions also tend to aggregate after the irradiation process and are also eliminated from the surfaces for the highest ion fluences. In this work we continue our previous work by studying the effect of the temperature of the sample in the range 300-600 K during Ion Beam Sputtering of CZT crystals surfaces at different fluences, by means of Scanning Electron Microscopy, Atomic Force Microscopy, and μ-Photoluminescence. It is expected that increasing the temperature of CZT samples during the irradiation process will enhance the beneficial effects this technique has shown when trying to reduce surface Te inclusions and to increase the luminescence properties of CZT crystal surfaces.- Publication:
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Journal of Crystal Growth
- Pub Date:
- November 2019
- DOI:
- 10.1016/j.jcrysgro.2019.125219
- Bibcode:
- 2019JCrGr.52625219P
- Keywords:
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- A.1 Defects;
- A.2 Gradient freeze technique;
- B.2 Semiconducting cadmium compounds;
- B.2. Semiconducting II-VI materials