Bridgman Growth And Assessment Of Cdte And Cd1-Yznyte Crystals

In order to meet with the epitaxial growth of large area Hg 1-xCd xTe (MCT) with various compositions for infrared focal plane arrays, CdTe and Cd 1-yZn yTe (y = 0.020, 0.025 and 0.040 for various x) crystals with 120 mm length and 20 - 40 mm diameter have been successfully synthesized and grown by the vertical Bridgman method. These crystals were grown unseededly or seededly and free of any macroscopic defects e.g. micro-cave and crackles. Wafers with areas from 12 �� 18 mm 2 to 30 �� 35 mm 2 in the <111> orientation have been obtained from large grain of the ingot. Effects of changing the ampoule base shape upon the crystal growth have also been investigated. A necked ampoule bottom is preferred to ones employing seeding. Assessments of the samples have included infrared transmission (range 2.4 - 24 ��m), etch pit density, X-ray photography and three-crystal rocking curve measurement. Good quality MCT epitaxial films (areas of 12 �� 18 mm 2 and 20 �� 20 mm 2), as demonstrated by good surface topography, electrical parameters, have been grown by liquid phase epitaxy and metal organic chemical vapor epitaxy onto CdTe(CT) and Cd 1-yZn yTe(CZT) substrate materials produced in our study.