A surface study of mercury-cadmium-telluride

Single crystals of Hg (sub 1-x) Cd (sub x) Te were studied to determine how changes in the surface conditions affected electrical properties, infrared detector grade material was used to examine the effects of changes in the surface charge density on electrical l/f noise. The surface charge density which was controlled by the pH of the aqueous solution was measured in a zeta meter which operated much like a Millikan oil drop experiment. The electrophoresis zeta potential measurements on (HgCd)Te have identified the active surface oxide as TeO2 and has also revealed information on the surface chemistry. Electrical l/f noise in-(HgCd)Te was found to be dominated by bulk and not surface effects at room temperature. Laser Raman and Auger spectroscopy were used to assess mechanical surface damage and anodic oxide composition.