Highly oriented layers of the three-dimensional semiconductor CdTe on the two-dimensional layered semiconductors MoTe2 and WSe2

Abstract

The II–VI semiconductor CdTe was sequentially deposited onto the (0001) van der Waals surfaces of the layered compound semiconductors MoTe2 and WSe2 by molecular beam epitaxy. Growth could only be achieved after deposition of a nucleation layer of CdTe at room temperature. After nucleation subsequent deposition steps followed at increased substrate temperatures (T=170–370 °C) in order to increase the crystalline quality of the films. The deposited films were investigated after each growth step by low energy electron diffraction and photoelectron spectroscopy. The diffraction pattern indicates a facetting of the (111) oriented film surfaces. From photoemission data we exclude interface reactions between substrate and film material. Transmission electron microscopy was used to examine the film morphology after the UHV experiments. The mean diameter of the film crystallites is 200–400 Å.