Long-wave infrared emission properties of strain-balanced InAs/In_xGa_1−xAs_ySb_1−y type-II superlattice on different substrates

High-performance type-II superlattices of III–V semiconductor materials play an important role in the development and application of infrared optoelectronic devices. Improving the quality of epitaxial materials and clarifying the luminescent mechanism are of great significance for practical applications. In this work, strain-balanced and high-quality InAs/In_xGa_1−xAs_ySb_1−y superlattices without lattice mismatch were achieved on InAs and GaSb substrates successfully. Superlattices grown on InAs substrate could exhibit higher crystal quality and surface flatness based on high-resolution X-ray diffraction (HRXRD) and atomic force microscopy (AFM) measurements’ results. Moreover, the strain distribution phenomenon from geometric phase analysis indicates that fluctuations of alloy compositions in superlattices on GaSb substrate are more obvious. In addition, the optical properties of superlattices grown on different substrates are discussed systematically. Because of the difference in fluctuations of element composition and interface roughness of superlattices on different substrates, the superlattices grown on InAs substrate would have higher integral intensity and narrower full-width at half maximum of long-wave infrared emission. Finally, the thermal quenching of emission intensity indicates that the superlattices grown on the InAs substrate have better recombination ability, which is beneficial for increasing the operating temperature of infrared optoelectronic devices based on this type of superlattices.