1,721,076 research outputs found
Plasmon-enhanced Ge-based metal-semiconductor-metal photodetector at near-IR wavelengths
Full text linkWe demonstrate the use of plasmonic effects to boost the near-infrared sensitivity of metal-semiconductor-metal detectors. Plasmon-enhanced photodetection is achieved by properly optimizing Au interdigitated electrodes, micro-fabricated on Ge, a semiconductor that features a strong near IR absorption. Finite-difference time-domain simulations, photocurrent experiments and Fourier-transform IR spectroscopy are performed to validate how a relatively simple tuning of the contact geometry allows for an enhancement of the response of the device adapting it to the specific detection needs. A 2-fold gain factor in the Ge absorption characteristics is experimentally demonstrated at 1.4 µm, highlighting the potential of this approach for optoelectronic and sensing applications.QCD/Scappucci La
Straining Ge bulk and nanomembranes for optoelectronic applications: a systematic numerical analysis
Full text linkTop–down SiGe nanostructures on Ge membranes realized by e-beam lithography and wet etching
No full textSiGe nanostructures on Ge membranes have been fabricated by electron beam lithography and anisotropic wet chemical etching, starting from SiGe/Ge heterostructures epitaxially deposited on Si substrates. Two different top-down approaches have been studied in order to obtain the best freestanding structures. We find that the process in which the Ge membrane is suspended after the lithography of the SiGe nanostructures leads to high quality SiGe nanostructures without damage to either the SiGe nanostructures or the Ge membrane. The structures have been systematically analyzed at every step of the fabrication process, by scanning electron microscopy and by atomic force microscopy
Modulation of Si(100) electronic surface density due to supramolecular interactions of gaseous molecules with self-assembled organic monolayers
No full textChemically induced disordering of Si (100) surfaces upon SC1: SC2 etching analysed by high-resolution transmission electron microscopy
No full textExperimental evidence and computational analysis of the electronic density modulation induced by gaseous molecules at Si(001) surfaces upon self-assembling organic monolayer
No full textHigh quality SiGe electronic material grown by low energy plasma enhanced chemical vapour deposition
No full textLow energy plasma enhanced chemical vapour deposition (LEPECVD) is a relatively new growth method, which has been used to create high quality epitaxial silicon germanium material on conventional Si(001) wafers. This material is eminently suitable for electronic devices. The best performance for n-type and p-type conduction is seen in tensile-strained Si and compressively strained Ge quantum wells, respectively. Since such quantum wells cannot be grown directly on a silicon substrate, a virtual substrate (VS) is first grown. The reactive conditions within the plasma make it possible to grow the VS at rates of up to 10 nms−1 independent of substrate temperature. The quantum wells were grown using a lower plasma intensity, at growth rates of approximately 0.3 nms−1. The electrical properties of the material compare very well with molecular beam epitaxy (MBE) references, and hybrid material where the buffer is grown by LEPECVD and the electrically active layers are grown by MBE. In addition, the structural quality of the material is analysed by atomic force microscopy, transmission electron microscopy and defect etching
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