Funding: H. F. and W. W. acknowledge support by Olle Engkvists Stiftelse, Carl Tryggers Stiftelse, and together with S. D. by Chalmers Area of Advance Nano. W. W. acknowledges support by the Knut and Alice Wallenberg Foundation through a Wallenberg Academy Fellowship. Samples were fabricated in the Myfab Nanofabrication Laboratory at Chalmers. S. D. acknowledges financial support from European Union Graphene Flagship (Core 3, No. 881603), 2D TECH VINNOVA center (No. 2019-00068). Q. L. and S. X. acknowledge the support from the Independent Research Fund Denmark (project no. 9041-00333B and 2032-00351B), Direktør Ib Henriksens Fond, and Brødrene Hartmanns Fond. Y. Z. and Z. S. acknowledge the support from Horizon Europe (HORIZON) Project: ChirLog (101067269), the Academy of Finland (grants 314810, 333982, 336144, 336818, 352780, and 353364), Academy of Finland Flagship Programme (320167, PREIN), the EU H2020-MSCA-RISE-872049 (IPN-Bio), and ERC advanced grant (834742). E. M. acknowledges support from Deutsche Forschungsgemeinschaft (DFG) via CRC 1083 (project B09).

Data accompanying arXiv:2307.03842 [cond-mat.mes-hall] (2023): 1. All the spectrum data is .sif formated file, which can be read by Matlab (sifReader in Matlab script folder). 2. All the functions needed for plotting and reading data are placed in the Matlab script folder 3. Plot_sif_spectrum_data.m is used to plot PL spectrum. 4. loadQutag.m is the function used to import lifetime data acquired from Qutag. 5. FuncPowerSlope.m is the function used for fitting the power dependent PL data. 6. FuncSatPower.m is the funciton used for fitting the saturation curve and getting the saturation power, see the inset of Fig2a. 7. FuncArrhenius.m is the function used for fitting the temperature depedent PL data, see the inset of Fig2d. 8. Func_2lifetime.m is the function used for fitting the lifetime data with biexponential function, see FigS7 9. convert_SIF_to_mat.m is used to convert hyperspectral imaging data in .sif to .mat 10. Plot_PLmap.m is used to plot PL map.