Entangled photon-pair sources are foundational to advancing quantum technologies, including secure communication, quantum sensing, and imaging. By nanopatterning NbOCl2 into a high-quality-factor metasurface, we achieve three orders of magnitude enhancement in photon-pair generation efficiency via resonant excitation of bound states in the continuum resonance, which intensify light-matter interactions. Furthermore, we demonstrate in situ electrical tunability of the photon-pair emission wavelength over a 250 nm range (1450–1700 nm) by dynamically modulating surrounding liquid crystal layer. Remarkably, the decoupling of photon-pair generation rate and spectral tunability ensures high brightness, above 104 coincidences, under active tuning. The air stability and mechanical robustness of NbOCl2 further enhance its practicality for real-world deployment. This work establishes NbOCl2 as a superior material for scalable, on-chip quantum light sources, paving the way for integrated quantum communication systems, adaptive sensors, and portable quantum devices.

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