Semiconductor Nanophotonics
Students: AlexGuichard, LinyouCao, RohanKekatpure, PengyuFan
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