The automatic determination of cadmium-mercury telluride composition

This paper describes the use of a fully automated Fourier-transform infrared spectrophotometer system to scan the composition of bulk slices of CdxHg1−xTe for the range 0.15<x< 0.35 and its calibration to analytically determined X values. The most useful correlation established is for the n type, between the 300 K IR cuton defined by the zero-transmission intercept of a line tangent to the transmission curve at 1/e of its maximum and the composition parameter X as determined by wet chemical analysis. The overall prediction accuracy of true X is better than 0.005. Other cuton definitions, implementation pitfalls, and X correlations with both p-type transmission and 300 K carrier concentration are also discussed.