It was recalled that Yb and Sm exhibited an uniquely reactive behavior on (Cd,Hg)Te surfaces, due to a large rare-earth affinity for both Hg and Te. Semi-empirical calculations of the thermodynamic parameters suggested that the rare earths should act as effective diffusion barriers at the interface between (Cd,Hg)Te, and reactive metals such as Al, In or Cr. The results of a synchrotron radiation photo-emission investigation indicated that Yb layers were effective in preventing Al/Te reaction and in reducing Al-induced Hg depletion of the substrate. The data confirmed that the diffusion barrier effect resulted from the greater thermodynamic stability of (Cd,Hg)Te/Yb reaction products at the interface.

A.Raisanen, A.Wall, S.Chang, P.Philip, N.Troullier, A.Franciosi, D.J.Peterman: Journal of Vacuum Science and Technology A, 1988, 6[4], 2741-5