Optical characterization of the HgCdTe-based composite structure obtained by Ag ion implantation

The results concerning the formation of nano-scale patterns on the surface of a ternary compound are presented. The evolution of surface morphology of (111) Hg_1−xCd_xTe (MCT) (х ~ 0.223) epilayers due to ion irradiation in the energy range of 100–140 keV was studied. Modification of the surface was performed using the method of normal (θ = 0°) and oblique—incidence (θ = 45°) bombardment by Ag⁺ ions. Surface characteristics were investigated using atomic force microscopy and X-ray photoelectron spectroscopy techniques. Low-temperature photoluminescence and Raman spectroscopy were used for the investigation of the recombination and vibrational properties as well as the defect-impurity states of as-grown and implanted Hg_0.777Cd_0.223Te epilayers. It was found that ion beam structured regions of MCT surface demonstrate photoluminescence emission in the range of 500–850 nm, with intense peaks at around 733 nm (1.69 eV) and 570 nm (2.16 eV) with a long-wavelength shoulder at 620 nm (2 eV). The observed emission lines are suggested to be mainly related to the presence of various point defects in oxide phases (CdO and Ag₂O) induced by ion bombarding in the base material (HgCdTe).