Conductivity type conversion in Hg1-xCdxTe

The Schaake model for the p to n-type conversion in Hg1-xCdxTe caused by annealing in Hg vapor has been extended to obtain an analytic expression for x(J)(2)/t in terms of basic defect parameters and the background donor concentration (x(J) is the p-n junction depth at time t). Fitting of the Schaake equation for the depth of the skin-core boundary to the results of Bogoboyaschii enables estimates to be obtained for the values of the defect parameters involved in Hg0.8Cd0.2Te. These values are compared with those from simulations using SUMerCad. Good agreement is found between the new analytic expression for x(J)(2)/t and the available experimental evidence. Type conversion caused by ion beam milling and anodized surfaces can also be described by the new expression if the concept of an effective Hg interstitial surface concentration is introduced.