Fig. 5: Variation in G center optical response across junction.

a The ensemble response is analyzed across the confocal PL map of Fig. 4c from 0 and to -200 V. Close to the n-contact (brown), the ensemble experiences complete optical modulation and wavelength tuning. Tuning depicted as distance between dotted lines (full data set is given in Fig. 3). At the junction center (red), the ensemble experiences partial optical modulation with no wavelength tuning. b Ensemble center-wavelength redshift versus applied reverse bias of 1.24 ± 0.08 GHz/V, obtained from Gaussian fits of Fig. 3a data (details in Supplementary Note 2). Linear fit given with one standard deviation. c Illustration of observed reverse-bias redshift. The junction depletion (wavy curves) reaches the ensemble (center orange square with black emitters) at a sufficiently large threshold voltage (blue to teal colors), resulting in wavelength tuning. d Spatial correlation between simulated band bending (dashed lines) and 1D slice of the experimentally measured ZPL intensity (solid lines) at increasing reverse bias.