The dependence of the structural properties on the period numbers and the CdTe thicknesses in HgTe/CdTe superlattices

Abstract

Double-crystal X-ray rocking curve (DCRC) measurements were performed on HgTe/CdTe superlattices grown by molecular beam epitaxy (MBE) in order to investigate the dependence of the structural properties on the superlattice period number and the CdTe layer thickness. The results of the DCRC measurements showed that the full width at half maximum (FWHM) value of the principal peak decreased with increasing superlattice period number. As the CdTe layer thickness approached the HgTe layer thickness, the FWHM value corresponding to the principal peak decreased, and the optical absorption decreased. As the CdTe layer thickness changed, the detectable range of the HgTe/CdTe superlattice related to the value of the cut-off wavelength varied. These results indicate that HgTe/CdTe superlattices with various superlattice periods and CdTe layer thicknesses hold promise for potential applications in infrared photodetectors operating in a wavelength region between 4.3 and 12.5 μm.