Metal contacts on Hg_1−xCd_xTe

The available literature concerning metal contacts on Hg_1−xCd_xTe is reviewed in order to obtain a systematic overview. The theory and models available predict that, for metal in intimate contact with Hg_1−xCd_xTe , ‘‘ohmic’’ contact will be easily formed on n‐type and rectifying on p‐type Hg_1−xCd_xTe. This is in agreement with experimental results. There is evidence that metal atoms can move into the Hg_1−xCd_xTe, doping it and thus changing the electrical properties of the contact. Photoemission spectroscopy shows that Hg_1−xCd_xTe can be strongly disrupted by the deposition of the metal and correlation is found between heats of formation and heats of solution and the extent of this disruption. However, even for cases such as Ag where these bulk thermodynamic parameters are small, evidence is found for disruption of the lattice and movement of the metal into the Hg_1−xCd_xTe, producing doping. Formation of diffusion barriers and cooling to low temperature (100 K) have been explored as ways to limit this disruption.