Bright single photon emitters with enhanced quantum efficiency in a two-dimensional semiconductor coupled with dielectric nano-antennas

Single photon emitters (SPEs) in 2D semiconductors can be deterministically positioned using localized strain induced by underlying nanostructures. Here, the authors show SPE coupling in WSe2 to GaP dielectric nanoantennas, substantially increasing quantum efficiency and photoluminescence brightness. Single photon emitters in atomically-thin semiconductors can be deterministically positioned using strain induced by underlying nano-structures. Here, we couple monolayer WSe2 to high-refractive-index gallium phosphide dielectric nano-antennas providing both optical enhancement and monolayer deformation. For single photon emitters formed on such nano-antennas, we find very low (femto-Joule) saturation pulse energies and up to 10(4) times brighter photoluminescence than in WSe2 placed on low-refractive-index SiO2 pillars. We show that the key to these observations is the increase on average by a factor of 5 of the quantum efficiency of the emitters coupled to the nano-antennas. This further allows us to gain new insights into their photoluminescence dynamics, revealing the roles of the dark exciton reservoir and Auger processes. We also find that the coherence time of such emitters is limited by intrinsic dephasing processes. Our work establishes dielectric nano-antennas as a platform for high-efficiency quantum light generation in monolayer semiconductors.

Automated summary

Deterministic positioning of single photon emitters in 2D semiconductors can be achieved through localized strain induced by underlying nanostructures, with coupling to dielectric nanoantennas leading to substantial improvements in quantum efficiency and photoluminescence brightness. This approach allows for low saturation pulse energies and significantly brighter photoluminescence, with a 5-fold increase in average quantum efficiency observed. Furthermore, dielectric nano-antennas are established as a platform for high-efficiency quantum light generation in monolayer semiconductors.