High-energy electron irradiation-induced changes in interfacial atomic diffusion and luminescent behavior of InAs/InAsSb type II superlattices

InAs/InAsSb type II superlattices are widely used in the field of infrared optoelectronics . However, their physical properties, particularly under high-energy electron irradiation , and the associated emission characteristics, remain poorly understood. This work reports the effects of irradiation on the physical properties of InAs/InAsSb superlattices . We performed a comparative analysis on samples before and after irradiation, utilizing high-resolution X-ray diffraction (HRXRD), atomic force microscopy (AFM), and transmission electron microscopy (TEM). Our findings indicated that irradiation can induce lattice mismatch and surface roughness . Moreover, geometric phase analysis (GPA) revealed that Arsenic (As) segregation and elemental mixing (As-Sb) intensify with increasing radiation doses. To further assess the impact, we examined the luminescence characteristics using photoluminescence spectra. The results demonstrated that the broadening of the spectral full width at half maximum (FWHM) post-irradiation is primarily due to non-uniform broadening. Additionally, changes in the longitudinal optical phonon energy directly reflect the internal component fluctuations within the alloy layer caused by irradiation. Furthermore, high-energy electron irradiation was found to introduce Shockley-Read-Hall (SRH) recombination centers . The increased activation energy required for non-radiative recombination suggests that these SRH centers are situated in a deeper energy state.