Semiconductor Nanophotonics

Synthesis and Light Emission of Silicon Nanowires
Synthesis of Si nanowires
Most established: Vapor-Liquid-Solid Mechanism (VLS)
Au nanoparticles catalyze the decomposition of SiH_4 gas
Au and Si form a liquid phase alloy above the eutectic temperature
Decomposition of SiH_4 causes a supersaturation of the Au/Si alloy particle
Si nanowires grow from the supersaturated alloy
Au nanoparticle size determines the diameter of the nanowire
Au is a deep trap in Si, causing fast non-radiative decay!
Other materials can act as growth catalysts

Nanowire furnace with flashlamp heating

Light emission from oxidized TiSi2- and Co-catalyzed wires

Oxidation shrinks wire core diameter, induces confinement
passivates Si wire surface
PL decay lifetimes are roughly 10 us
Emission consistent with emission from Quantum confinement of carriers in the crystalline Si nanowire core.
Semiconductor Nanowire Nanophotonics and Optoeletronics
Engineering light absorption and scattering in semiconductor nanowire devices
Leaky Mode Resonances (LMRs), which can gently confine light within subwavelength, high-refractive-index semiconductor nanostructures, will give rise to enhanced eletromagnetic field intensity in these nanostructures, and thus allow rational control over their optical properties and provide a wide range of intriguing opportunities for design of nanophotonic and optoelectronic devices.

Resonant Germanium Nano-Antenna Photodetector
Semiconductor Nanowires Optical Antenna Solar Absorbers
Tuning the Color of Silicon Nanostructures
Efficient Optical Coupling of Silicon Nanoscale Resonators