Fig. 3

Cooperative exciton-polariton condensation (CEPC). a, b Angle-resolved PL spectra for the QDs thin film on DBR below the pump threshold and twice the pump threshold. The yellow dashed circles highlight the condensation area. c PL spectra and the blueshift of the peak energy (inset) under various pump densities. d Evolution of the emission intensity and linewidth as a function of the pump density. The orange area represents the SF interval, and the yellow area represents the CEPC interval. The purple arrows in (c, d) represent the nonlinear threshold for the CEPC