Infra-Red materials activities at GEC-Marconi Infra-Red Limited .1. Bulk growth techniques

Infra-red detectors based on cadmium mercury telluride (CMT) have been produced at GEC-Marconi Infra Red Ltd. for the past three decades. This paper describes the history and present position for the associated materials activities encompassing elemental purification and bulk crystal growth via Bridgman and accelerated crucible rotation technique (ACRT) processes. The bulk growth and assessment of CdTe-based substrate materials used in the epitaxial processes are also considered in this paper. Epitaxial growth, via liquid phase epitaxy (LPE) and metal-organic vapour phase epitaxy (MOVPE) processes, is covered in Part II of this article, to appear in a subsequent issue.