Enhanced single photon emission from carbon nanotube dopant states coupled to silicon microcavities

Single-walled carbon nanotubes are a promising material as quantum light sources at room temperature [1,2] and as nanoscale light sources for integrated photonic circuits on silicon [3]. Here we show that integration of dopant states in carbon nanotubes (Fig. 1a) and silicon microcavities (Fig. 1b) can provide bright and high-purity single photon emitters on silicon photonics platform at room temperature [4]. We perform photoluminescence spectroscopy and observe enhancement of emission from the dopant states by a factor of ~50, and cavity-enhanced radiative decay is confirmed using time-resolved measurements, where ~30% decrease of emission lifetime is observed. Statistics of photons emitted from the cavity-coupled dopant states are investigated by photon correlation measurements, and high-purity single photon generation is observed (Fig. 1c). Excitation power dependence of photon emission statistics shows that the degree of photon an-tibunching can be kept high even when the excitation power increases, while single photon emission rate can be increased up to ~1.7 x 10⁷ Hz.