Growth of CdTe Crystal via A Te Self-Flux Directional Solidification Method

Cadmium telluride (CdTe) crystal is one of the most ideal semiconductor materials for making room temperature X-ray and γ ray detectors, which has a wide application prospect in medicine, food, security inspection, nuclear waste monitoring and other fields. A Te self-flux directional solidification technology was proposed to grow CdTe crystal. Under the combined action of zone melting temperature field and crucible rotating system, the ideal solid-liquid interface morphology with micro bulge or flat shape was obtained. The single crystal area in the cross section of 25 mm CdTe crystal can reach 70%, and the single crystal with the size of 15 mm×15 mm×3 mm can be cut from the ∅56 mm CdTe crystal. Electrical test shows the CdTe crystal has excellent electrical properties under the condition of undoped modification, and the resistivity is up to 10⁸ Ω·cm. The infrared transmission analysis shows that CdTe crystal contains Te inclusions with a size range of 1-20 μm, which is the main micro defect in the growth process. The results obtained have certain reference value and significance for the future development of CdTe crystal growth technology.