Study of the Crystalline State of MBE (013)HgCdTe/CdTe/ZnTe/GaAs Heterostructure Layers by the Second Harmonic Generation Method

Abstract

The crystal perfection of HgCdTe layers of heterostructures grown on (013)GaAs substrates with ZnTe and CdTe buffer layers and orientation rotation in the plane(angle φ) and perpendicular to the growth direction (angle theta) were studied by the method of second harmonic generation. A change in the angle φ for CdTe layers was observed depending on the GaAs substrate orientation and its non-monotonic change throughout thickness in the MCT layer of constant composition and graded widegap layers at its boundaries. An increase in the angle theta was observed when growing the upper graded widegap MCT layer. The absolute value of the angle theta can be used for a qualitative assessment of the crystalline perfection of the HgCdTe layers. Keywords: crystals of the sphalerite class, second harmonic, azimuthal angular dependencies, crystal perfection, CdxHg1-xTe heterostructures.