On the adsorption and interface diffusion of Sn on CdTe(001)

The adsorption of Sn has been studied on ion bombarded and annealed CdTe(001). Unlike similar experiments on InSb(001) large changes in behaviour are observed using He scattering, LEED and AES as increasing numbers of layers are deposited and annealed. Using the height of the (00) peak as a function of coverage and T s during deposition and anneal it is observed that the surface changes in nature with increasing number of layers deposited. Diffraction properties and AES add further evidence of these changes as well as the width of the He (00) peak which seems to be very sensitive to the chemical modifications occurring at the interface. It is suggested that the final surface attained is composed of small aligned crystallites of SnTe which, in the bulk, has a slightly smaller lattice spacing (0.86% mismatch) than CdTe and α-Sn. α-Sn adsorbs pseudomorphically on this surface. A better developed surface of SnTe would prove interesting in order to study the properties of a slightly greater strained α-Sn layer than is attainable on InSb(001) or CdTe(001) to which it is closely lattice matched (0.1 → 0.15%).