Molecular-beam epitaxy growth and properties of BexZn1−xTe alloys for optoelectronic devices

Abstract

We report the molecular-beam epitaxy growth and characterization of BexZn1−xTe epitaxial layers on (100) InP substrates. BexZn1−xTe layers with x varying from 0 to 0.58 were grown. Good control of the composition is achieved by adjusting either the Be or the Zn cell temperatures. The layers exhibit high-crystalline quality, as established by double crystal x-ray diffraction and etch pit density measurements. Narrow x-ray rocking curves with a linewidth of 72 arcsec and etch pit density of 5×105 cm−2 are obtained for the BexZn1−xTe layers closely lattice matched to the InP substrate. BexZn1−xTe layers under tensile strain, which have higher BeTe content, exhibit slower degradation of the crystalline quality as a function of lattice mismatch than layers under compressive strain. The lattice-hardening properties of BeTe are proposed to be the reason for this behavior.