Effects of short- and long-range disorder in the photoluminescence of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>GaAs</mml:mi> <mml:mrow> <mml:mn>1</mml:mn> <mml:mo>−</mml:mo> <mml:mi>x</mml:mi> </mml:mrow

III-Sb semiconductor nanostructures provide sophisticated materials for developing optoelectronic applications in the near- and midinfrared wavelengths, for which the capability of engineering band alignments and wave functions is highly desirable. Segregation and diffusion at the interfaces, however, are features commonly found in Sb-based structures, impacting device performance and optical properties. By using type-II ${\mathrm{GaAs}}_{1\ensuremath{-}\mathit{x}}{\mathrm{Sb}}_{\mathit{x}}/\mathrm{GaAs}$ quantum wells as a platform, we demonstrate the effects of short- and long-range disorders in their optical emission, resulting in localization effects, broadening, and the emergence of a lower-energy band. The luminescence is characterized by varying excitation power, temperature, and magnetic field. Our findings demonstrate the presence of local potential minima of $\ensuremath{\sim}10\phantom{\rule{0.16em}{0ex}}\mathrm{meV}$ arising from the short-range contribution, the transition from correlated to uncorrelated electron-hole pair recombination, and the complex carrier dynamics in these systems.