Optoelectronic silicon-based

It is highly likely that by the second decade of the new millennium silicon-based computing will have reached fundamental technological or physical limits. Computers will therefore be based on substrates that exhibit superior performance characteristics. One possibility is the photon. Optoelectronic devices, which use substrates such as gallium arsenide, permit the interconversion of electrons and photons. Hybrid computers, which may already be available commercially by 2010, would use silicon for computation and photons for data transfer. The coherent modulation of very-high-frequency light beams enables many high-capacity... 

Shortly after the observation of visible PL from micro PS at room temperature [Cal], the first EL from a solid-state device was reported [Ri2]. This initiated vigorous research, because silicon-based optoelectronic devices seemed to be within reach. After several years of intense research the potential and the main problems involved with the EL from PS have been clarified. 

Materials processing, via approaches like chemical vapor deposition (CVD), are important applications of chemically reacting flow. Such processes are used widely, for example, in the production of silicon-based semiconductors, compound semiconductors, optoelectronics, photovoltaics, or other thin-film electronic materials. Quite often materials processing is done in reactors with reactive gases at less than atmospheric pressure. In this case, owing to the fact that reducing pressure increases diffusive transport compared to inertial transport, the flows tend to remain laminar. 

Partially functionalized cyclopolysilanes recently attracted attention as model substances for siloxene and luminescent silicon. The yellow luminescent silicon is formed by the anodic oxidation of elemental silicon in HF-containing solutions and may be used for the development of silicon-based materials for light-emitting structures which could be integrated into optoelectronic devices77. Because the visible photoluminescence of... 

M. Tischler, R. Collins, M. Thewalt and G. Abstreiter Silicon-Based Optoelectronic Materials, (Eds.), MRS Symposia Proceedings 290, Materials Research Society, Pittsburg, 1993. 

This movement is a key challenge for the entire field of advanced materials, but it is a particularly exciting challenge for silicon-based polymers. From the point of view of materials, silicon-based polymers span the three traditional domains plastics, ceramics, and metals. Potential applications are equally diverse. Silicon-based polymers range from structural materials, to optoelectronic devices, and to speciality materials for biomedical applications. We are in a unique position to capture the benefits of this merger of materials and polymer science. 

Silicon is the most widely used material in the electronics industry. To develop silicon-based devices for optoelectronic applications, one would like to make silicon a photon-emitting material. Unfortunately, silicon is an indirect gap semiconductor and, thus, the efficiency of photon emission is extremely low since the radiative recombination of the electron-hole pair is not allowed without the assistance of a momentum-conserving phonon. Moreover, the existence of defects leads to an almost total quenching of this rather unlikely process. 

However, R-doped semiconductors have evolved into a whole new field due mainly to the hope of obtaining silicon-based optoelectronic devices (Polman et al. 1993), that is, even using an indirect-gap semiconductor with no active optical property of its own. This field has been recently reviewed by Pomrenke et al. (1993). 

Ben-Chorin M, Moller F, Koch F, Schirmacher W, Eberhard M (1995a) Hopping transport on a fractal ac conductivity of porous silicon. Phys Rev B 51 2199 Ben-Chorin M, Moller F, Koch F (1995b) Band alignment and carrier injection at the porous-silicon-ciystaUine-silicon interface. J Appl Phys 77 4482 Bhattacharya E, Ramesh P, Suresh Kumar C (2000) J Porous Mater 7 299 Bisi O, Ossicini S, Pavesi L (2000) Porous sihcon a quantum sponge structure for silicon based optoelectronics. Surf Sci Rep 38 1... 

Barthelemy P, Ghulinyan M, Gaburro Z, Toninelli C, Pavesi L, Wiersma DS (2007) Optical switching by capillary condensation. Nat Photonics 1(3) 172-175 Billat S, Thonissen M, ArensFischer R, Berger MG, Kruger M, Luth H (1997) Influence of etch stops on the microstructure of porous silicon layers. Thin Solid Films 297(l-2) 22-25 Bisi O, Ossicini S, Pavesi L (2000) Porous silicon a quantum sponge structure for silicon based optoelectronics. Surf Sci Rep 38(1-3) 1-126... 

Bisi O, Ossicini S, Pavesi L (2000) Porous silicon a quantum sponge structure for silicon based optoelectronics. Surf Sci Rep 38(l-3) 5-126... 

Hybrid integration of light emitters and detectors with SOI-based micro-opto-electro-mechanical (MOEMS) systems, Proc. SPIE 4293, Silicon-Based and Hybrid Optoelectronics III, D.J. Robbins, J.A. Trezza, G.E. Jabbour, Eds., pp. 32-45 (2001). 

During the last decade GaAs-based micro- and optoelectronics has developed from a military niche to a global commercial player that does not replace but supplement silicon-based devices. This development has been due to some unique physical properties of compound semiconductors allowing for superior functionality of devices and the progress made in the production of single crystals and wafers/substrates, which has now reached maturity. 

A photovoltaic material generates a voltage when it is exposed to light and photovoltaic can be considered as a specialized area of optoelectronics. The principle has been known for many decades but it became a industrial reality only in 1958 when an array of photovoltaic cells, based on single-crystal silicon, provided power for a space vehicle. 

The hydrogen content Ch greatly influences structure and consequently electronic and optoelectronic properties. An accurate measurement of Ch can be made with several ion-beam-based methods see e.g. Arnold Bik et al. [54]. A much easier accessible method is Fourier-transform infrared transmittance (FTIR) spectroscopy. The absorption of IR radiation is different for different silicon-hydrogen bonding configurations. The observed absorption peaks have been indentified [55-57] (for an overview, see Luft and Tsuo [6]). The hydrogen content can be determined from the absorption peak at 630 cm , which includes... 

The construction of the optoelectronic interface can be based on a silicon photodiode since analytical and reference wavelengths are from the visible and the IR regions, respectively. The signals can be filtered out by optical filters (then two photodiodes are required) or one photodiode can be synchronised with modulation waves of the LEDs used. Finally, silica optical fibres can be used as light waveguides. The choice between single fibre or bundle is determined by the application of the sensor. 

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