The project will develop state-of-the-art GaN-based polariton lasers that operate at ambient conditions with the lowest threshold powers of the literature. Such optimized polariton lasers will be then investigated as efficient room temperature sources of entangled photons, exploiting parametric scattering processes of polaritons. In parallel, the project will demonstrate band-gap engineered InAs quantum-dot-based single photon emitters that will operate at non-cryogenic temperatures (T ≥ 220K), which can be provided by a low-cost thermoelectric cooler. It will also develop a new interesting class of highly-strained GaAs quantum dots inside strongly lattice-mismatched core-shell nanowires.