Er-implanted WS2 flakes with room-temperature photon emission at telecom wavelengths

Rare earth ions in solids promise applications in quantum communication and nanoscale sensing, but circumventing constraints imposed by the material host often prove challenging. In this work we combine ion implantation, IR confocal microscopy, and ab-initio calculations to demonstrate room-temperature telecom emission of Er3+ in exfoliated WS2 flakes. Confocal microscopy and optical spectroscopy reveal narrow, long-lived photoluminescence that activates after low-temperature thermal annealing. Polarization-selective measurements show a uniform response across the flakes, suggesting Er ions take equivalent positions in the WS2 lattice, possibly substituting tungsten. Quantum embedding calculations of ErW yield a set of PL lines in the telecom band, qualitatively consistent with our experimental observations. Our results create opportunities for novel solid-state devices coupling 2D-hosted, telecom-band emitters.