Heteroepitaxy of large grain Ge film on cube-textured Ni(001) foils through CaF2 buffer layer

摘要

Cube-textured Ni(001) foils have been considered as a viable alternative substrate to grow high quality functional films for large area optoelectronic devices. In this work, we report the heteroepitaxial growth of CaF2(001) films on cube-textured Ni(001) foils at 350-600 degrees C with in-plane orientation of CaF2[110]//Ni[100] and CaF2[(1) over bar 10]//Ni[010] with 45 degrees rotation respect to the Ni(001) substrate. Unlike CaF2(111)/Ni(001) films where there exist four independent rotational domains with rotational domain boundaries, CaF2(001)/Ni(001) contains no rotational domains or rotational domain boundaries. This makes CaF2(001)/Ni(001) films better candidates as templates for the growth of high quality functional semiconductors. We also demonstrate that Ge(001) film with no rotational domains and with a grain size of similar to 50 mu m similar to that of the Ni substrate can be grown on the CaF2(001) buffered Ni substrate. (C) 2016 Elsevier B.V. All rights reserved.