Structure of the CdTe/Cd0.959Zn0.041Te, Hg1-xCdxTe/CdTe, CdTe/GaAs heterojunctions

The strain tensor elements for an anisotropically relaxed CdTe epilayer at a low-symmetry (1 1 2)surface grown by molecular beam epitaxy (MBE) on the Cd0.0959Zn0.041Te(1 1 2)B substrate were determined by X-ray double crystal diffraction (XDCD). It was obtained that the strain tensor elements are epsilon(xx)=2.5x10(-3), epsilon(zz)=2.6x10(-3), epsilon(xz) = -1.15 x 10(-3), and the coherent factor is gamma approximate to -0.98 for the CdTe epilayer with a thickness of about 3 mu m. The structure of the Hg1-xCdxTe/CdTe and CdTe/GaAs heterojunctions on the [1 1 2] orientation were observed by high-resolution transmission electron microscopy (HRTEM). It was found that the nearly fully relaxed state (coherent factor approaches to 0) at the CdTe buffer layer on the GaAs(1 1 2)B substrate, the partially relaxed state at the CdTe/GaAs(1 1 2)B heterojunction, gamma approximate to -0.77, and the nearly fully strained state (coherent factor approaches to 1) at the Hg1-xCdxTe epilayer grown following the growth of the CdTe buffer layer on the GaAs(1 1 ?)B substrate. (C) 1999 Elsevier Science B.V. All rights reserved.