Solid-state quantum light sources (e.g., quantum dots, defect centers) are promising due to their high brightness, robustness, and device compatibility. Their surrounding medium affects light extraction efficiency and coherence through dephasing. Nanophotonic cavities enhance radiative coupling rates and directional emission. Structures like nanoantennas and circular Bragg gratings have been coupled to site-controlled single quantum dots. Additionally, nanoscale luminescence quenching enables single quantum dot selection, addressing spatial and spectral inhomogeneity for scalable quantum optical platforms.