Highly-efficient GaAs/AlGaAs Nanopillars and NanoLEDs via SiNx Surface Passivation

Nanolight sources employing III-V GaAs semiconductor materials as the gain medium are crucial for the fabrication of miniaturized optical sources such as nanoLEDs and nanolasers with emerging applications in 3D sensing, optical data communication, spectroscopy, medical diagnosis and even neuromorphic computing [1] . However, the surfaces of GaAs-based compounds and their interfaces with dielectrics tend to host large densities of electronically active defects. Particularly, when the devices are scaled to the deep subwavelength size (<<1 µm), a substantial increase of the nonradiative recombination at room-temperature leads to low-efficient nanolight sources and respective ultrashort lifetimes of ~100 ps, typically orders of magnitude smaller than the bulk material [2] . Recently, it has been suggested that passivation of GaAs with silicon nitride (SiN x ) can improve the electrical performance of GaAs [3] , but its impact in optical nanodevices remains almost unexplored.