Aleksandr S. Goltaev

Light emitting diodes (LEDs) based on III-V semiconductors are in a great demand for many appli cations and tend to be miniaturized. However, with downscaling of planar LEDs, the surface states on the structure sidewalls, acting as nonradiative recombination centers, begin to play a significant role and deteriorate the device performance. The transition from planar to nanowire-based geometry helps to overcome this limitation. Here, we introduce a bottom-up microLED structure based on epitaxial GaP/GaAsPN/GaP nanowire arrays grown on low-cost Si(111) wafers. The active region demonstrates bright photoluminescence in the red spectral region while the radial p-i-n structure allows for electrical pumping. The opto-electrical characteristics and performance of the suggested microLEDs remain with the miniaturization of devices down to microscale equivalent lateral size. Moreover, we didn’t observe an efficiency cliff even for current density exceeding 300 A/cm². The proposed architecture paves the way to a new generation of nanowire-based microLEDs.

Phosphorus-rich InAsP nanowires are grown on silicon via molecular beam epitaxy. Nanowires demonstrate room temperature photoluminescence at wavelengths as short as 1480 nm which is promising for optical communication and biomedical imaging.

Efficient second harmonic generation (SHG) in nanophotonic designs based on all-dielectric nanostructures demands materials with large values of the quadratic nonlinear susceptibility, low dissipative losses, and high refractive index. One of the best materials meeting all these parameters is gallium phosphide (GaP). However, second-order nonlinearity requires high crystallinity and morphology quality of the GaP layer grown for further lithographic processing. Here we develop a method to fabricate high-quality crystalline GaP metasurfaces, which demonstrate pronounced linear and nonlinear optical properties. Direct growth of a GaP layer on a sapphire substrate tackles the previous problem of wafer bonding, because of high optical contrast between fabricated resonant nanoparticles and the substrate. As a result, the fabricated GaP metasurface supports bound state in continuum mode with an experimental quality factor around 100 yielding a strong enhancement of SHG in narrow spectral range. We believe that the developed approach will become a versatile platform for nonlinear all-dielectric nanophotonics.