ASSESSMENT OF THE PURITY OF CADMIUM AND TELLURIUM AS COMPONENTS OF THE CDTE-BASED SUBSTRATES

In order to assess the purity of their Cd and Te components, CdTe crys tals have been grown by Bridgman using commercial batches of elements of purity ranging from 5N to 6N(+). The assessment has been achieved t hrough the classical optical and electrical techniques that solid stat e physics offers, on as-grown and annealed crystals. Some contaminatio n by residual accepters like Cu, Li, and P is shown to occur during th e high temperature growth, mainly if uncoated silica tubes are used, a s is emphasized within a comparison between the electrical and optical properties of crystals grown by melt-growth or at lower temperature b y solution-growth.