Towards a Scalable Platform for Site-Defined Single-Photon Sources

We present a wafer-scale route to deterministic single-photon emitters by nucleating self-assembled InAs QDs at defined GaAs sites without etching. Thermal mismatch between GaAs and SiO₂ creates strain-guided landscapes that funnel adatoms into designed minima. SiO₂ pockets induce compressive strain so nucleation begins at vertices where asymmetric diffusion then forms second-order minima near the center, where a controlled indium dose yields a single dot. Hyperspectral imaging confirms single-dot nucleation and ab-initio modeling shows boundary dots raise local chemical potential, suppress edge nucleation, and drive adatoms inward. The result is co-control of position, shape, and emission wavelength on atomically flat GaAs, with nanometer-scale placement, narrow inhomogeneous broadening (SD < 2.7 nm), and high single-dot yield per site (>60%). For electrical tunability, we embed the QD layer in a thin vertical p–i–n diode for Stark tuning and per-site charge control. We achieve 0.8 nm/V stable tuning for spectral alignment, Fourier-limited linewidths to 293 MHz under resonant drive, and discrete charge plateaus enabling deterministic trion loading. This etch-free, wafer-scale growth strategy unifies deterministic positioning with scalable patterning, enabling ordered QD arrays and chip-ready single-photon platforms for quantum communications and networking.