OPTICAL TECHNIQUES FOR COMPOSITION MEASUREMENT OF BULK AND THIN-FILM CD1-YZNYTE

The composition of high-quality single-crystal bulk-grown Cd1-yZn(y)Te (0 less-than-or-equal-to y less-than-or-equal-to 0.2) was determined from precision lattice constant measurements for a total of 22 data points. These samples were used to develop calibration curves for an accurate, contactless, nondestructive optical determination of composition using either 300 K transmission measurements or 77 K photoluminescence measurements. The 300 K transmission technique is useful for bulk CdZnTe wafers while the 77 K PL technique is applicable to both bulk and thin-film CdZnTe. Both techniques are useful in determining Cd1-yZn(y)Te composition in the range (0 less-than-or-equal-to y less-than-or-equal-to 0.2) which covers the range needed for lattice-matching to Hg1-xCd(x)Te and Hg1-xZn(x)Te epitaxial layers. The ability to map sample composition with high precision is available with both techniques.