Performance of field-emitting resonating carbon nanotubes as radio-frequency demodulators

International audienceWe report on a systematic study of the use of resonating nanotubes in a field emission (FE) configuration to demodulate radio frequency signals. We particularly concentrate on how the demodulation depends on the variation of the field amplification factor during resonance. Analytical formulas describing the demodulation are derived as functions of the system parameters. Experiments using AM and FM demodulations in a transmission electron microscope are also presented with a determination of all the pertinent experimental parameters. Finally we discuss the use of CNTs undergoing FE as nanoantennae and the different geometries that could be used for optimization and implementation. © 2011 American Physical Society

Novel bondpad report process for III-V semiconductor devices using full HSQ properties

This paper reports on an easy and quick planarization and passivation technique of III-V compound semiconductor compatible with nanoscale devices. Vertical etching requires good sidewalls passivation to reduce drastically the leakage current and to obtain a good planarization of the devices for metal connection. This novel technique offers the capability to planarize all the different compounds in the entire wafer independently of the height of the structure to be connected. This method uses the HSQ properties (fluidity, solidification to silica film by using O2 plasma treatment, negative tone e-beam lithography resist, low-k dielectric, etc.) to planarize and to passivate all the devices at once. We applied this quick and easy method to InP digital optical switches. We demonstrated photonic switches with high yield (>90%), high breakdown voltage (>30 V), low ohmic contact resistance (8 Ω) and a low leakage current (21 pA/μm2 for 5 V reversed bias)

Strong deviations from Fowler-Nordheim behavior for field emission from individual SiC nanowires due to restricted bulk carrier generation

We report here field-emission (FE) studies of individual single-crystal SiC nanowires that showed several distinct I/V regimes including strong saturation resulting in highly nonlinear Fowler-Nordheim plots. The saturation is due to the formation of a depletion layer near the nanowire ends as predicted for FE from semiconductors and appears after in situ control of the surface cleanliness. This work opens the door to improving the uniformity, stability, and photon control of mass-produced planar nanowire FE cathodes and shows how FE can be used for transport measurements on individual semiconducting nanowires

2x2 InP optical switching matrix based on carrier-induced effects for 1.55-µm applications

This letter demonstrates a 2 × 2 low optical crosstalk and low power consumption switching matrix device based on carrier-induced effects on an InP substrate. The matrix device comprises two digital optical switches (DOSs) with a wide multimode Y-junction associated with a sinusoidal passive integrated optical circuit with an optimized X-crossing. The passive structure was designed using a two-dimensional beam propagation method (BPM) and the entire InP-InGaAsP-InP DOS was designed using a semivectorial three-dimensional BPM. The fabricated 2 × 2 InP switching matrix heterostructure with λg = 1.3 μm exhibits optical crosstalk as low as -30.5 dB for drive current of 52 mA at 1.55-μm wavelength. Maximum crosstalk change of 4 dB is measured under optical polarization variation

High Q factor for mechanical resonances of batch-fabricated SiC nanowires

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Negative Differential Resistance in Laser-Assisted Field Emission from Si Nanowires

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Nanomécanique de nanofils SiC : vers des NEMS actifs

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