Fig. 3.

Optical properties of single gNCCs at 4 K. a, b PL spectra of two single gNCCs excited at < N > = 0.1. c Second-order photon autocorrelation measurement of a single gNCC with a g⁽²⁾(τ) value of about 0.15 at the zero-time delay. d PL spectra of a single gNCC excited at < N > = 0.1 and 0.3, respectively. e PL decay curves measured at < N > = 0.1 for the A, B, and C emission peaks of this single gNCC and fitted with single-exponential lifetimes of 10.9, 10.0, and 10.1 ns, respectively. f PL decay curves measured at < N > = 0.3 for the A, B, and C emission peaks of the same single gNCC. These curves are all fitted by biexponential functions with the fast/slow lifetimes of 0.8/10.1, 0.7/10.5, and 1.1/10.1 ns, respectively. The PL decay curve of an additional emission peak of D is also presented and fitted with a single-exponential lifetime of 0.9 ns