High Pressure Furnace Growth of Mercury Cadmium Telluride.
Final technical rept. Jun 73-Apr 76,
LITTLE (ARTHUR D) INC CAMBRIDGE MASS
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This program involved the preparation of mercury cadmium telluride HgCdTe for infrared detectors using high pressure furnace techology. The principal difference between this approach and other techniques is that there is no requirement to seal the ampoule the mercury vapor present during compounding and recrystallization is contained by the high pressure of inert gas in the furnace coupled with condensation of mercury vapor in the cool neck of the ampoule. The advantage of the method is that, unlike sealed ampoule techniques, the pressure can be varied during preparation and recrystallization and there can be direct access to the melt for temperature measurement. In all thirty ingots were prepared. The manufacturing variables included the rate and technique of solidification, furnace configuration, and times and temperatures during the recrystallization step. Initially difficulties in obtaining large grained crystals of uniform composition were encountered this was eventually attributed to an inability to control the temperature profile in the high pressure furnace during recrystallization. The technique finally adopted involved compounding and rapid solidification in the high pressure furnace followed by recrystallization of segments of the ingot in sealed quartz ampoules in a conventional furnace with a flat temperature profile.
- Infrared Detection and Detectors