Stark‐Tunable O‐Band Single‐Photon Sources Based on Deterministically Fabricated Quantum Dot ‐ Circular Bragg Gratings on Silicon

ABSTRACT Semiconductor quantum dots (QDs) offer outstanding quantum‐optical performance, making them promising for applications in quantum information technology. However, the simultaneous realization of wide‐range electrical tunability, efficient photon extraction, elevated‐temperature operation, and monolithic integration on silicon in combination with telecom‐wavelength compatibility remains a major unresolved challenge. Here, we demonstrate electrically contacted circular Bragg grating (eCBG) resonators incorporating InGaAs QDs grown on silicon, enabling bright single‐photon emission in the telecom O‐band. Deterministic electron‐beam lithography and a ridge‐based vertical p–i–n diode architecture allow precise device integration and electrical control of individual emitters. The QD‐eCBGs exhibit a quantum‐confined Stark shift of approximately 16 nm (11 meV) at 4 K, which presents a record value for a QD embedded in a nanophotonic structure at telecom wavelengths. This feature is combined with a photon extraction efficiency of (21.7 ± 3.0)%, while preserving excellent single‐photon purity. The measured values are g (2) (0) = 0.0078 ± 0.0012 below saturation and g (2) (0) = 0.0183 ± 0.0021 at saturation under pulsed excitation. Robust antibunching persists up to 77 K, yielding g (2) (0) = 0.0663 ± 0.0056, demonstrating operation within the temperature range accessible to liquid‐nitrogen and user‐friendly Stirling cryocoolers. Moreover, spatially separated QD‐eCBGs can be electrically fine‐tuned into spectral resonance. These results establish a silicon‐compatible telecom O‐band quantum light platform combining spectral tunability, single‐photon purity, and elevated‐temperature operation.