Ion beam induced infrared color centers in silicon as quantum emitters and sensors of irradiation damage

Infrared color centers in Si have become emerging candidates for on-chip integrated quantum emitters, optical access quantum memories and sensing. Here, we studied the formation dynamics of G color centers in Si with as-received carbon under various ion beam irradiations, and demonstrated using G centers as a sensitive probe for irradiation damage and atomic disorder. For G centers formed by 1 MeV cw proton irradiation, the G center preserves narrow optical linewidth < 0.08 nm, as fluence increased from 10⁹ cm^-2 to 10¹³ cm^-2. Meanwhile, under the ns-pulsed irradiation, the linewidth broadens significantly up to 0.13 nm, which indicates the pulsed protons creating a larger degree of atomic disorder. However, the PL decay time of G centers decreases for both irradiations as the proton fluence are increased, implying that the two different irradiations introduce a similar amount of nonradiative defects. The difference in linewidth broadening versus a similar amount of nonradiative defects between the two irradiations indicates that the pulsed proton introduces vacancy clusters causing a stronger degree of atomic disorder. In addition, we observe significantly broader G center linewidth (0.16 nm) from Ar irradiation, with 3 orders of magnitude more damage events, which further suggests the dense damage cascades induced vacancy clusters.