Evidence of stress-mediated Hg migration in Hg1−xCdxTe

Photoemission results from some 〈110〉 cleaved surfaces of Hg1−xCdxTe indicate that the Fermi level is pinned suggesting that while the bulk of the material is p type the area stressed during cleavage has been converted to n type. Electrolyte electroreflectance (EER) measurement confirmed the n-type character of the cleaved surface and showed that the alloy composition x at the surface, after cleavage, is high (x=0.22) compared to the bulk value (x=0.185). The high x value associated with the n character indicates that under stress the Hg migrates, at least partially, via the formation of donor defects. The defect density is reflected in the EER linewidth.