The development of the global quantum internet has progressed significantly in the recent years. It requires the simultaneous progress of very diverse quantum platforms, which thus entitles multitude of different challenges both theoretically and experimentally. In this thesis we approach several of these tasks by proposing single-photon sources as an important resource that provides with many valuable solutions, from an efficient loophole-free violation of Bell’s inequality (GonzálezRuiz et al., 2022a) to optimal implementations of Device-Independent Quantum Key Distribution protocols (González-Ruiz et al., 2022b). To this end we introduce a detailed analysis that model realistic imperfections of the sources (Bjerlin et al., 2023; González-Ruiz et al., 2022a), in order to reach a deeper understanding that allows us to set a clearer route for near-future experimental implementations. In addition, we present a full theoretical analysis (González-Ruiz et al., 2023) of the path-entangled states experimentally realised by Østfeldt et al. (2022) by means of a quantum-dot biexciton cascade placed in a chiral nanowaveguide, investigating their entanglement properties after the effect of several realistic imperfections. Finally, we propose an experimental set-up to match the typical broad bandwidth of photons generated by quantum-dot single-photon sources with that of quantum memories candidates such high-Q optomechanical membranes, with a bandwidth several orders of magnitude narrower. Our proposal allows thus to efficiently store the qubit carried by the photon.