Alcatel-Lucent

About: Alcatel-Lucent is a based out in Stuttgart, Germany. It is known for research contribution in the topics: Signal & Network packet. The organization has 37003 authors who have published 53332 publications receiving 1430547 citations. The organization is also known as: Alcatel-Lucent S.A. & Alcatel.

Printing Process Suitable for Reel‐to‐Reel Production of High‐Performance Organic Transistors and Circuits

Abstract: cause appropriate compounds now exist for many types of devices, research has expanded to include patterning methods that can take advantage of the easy processability of these materials. Although a recently described photolithographic process produced impressive results, [7] there may be advantages (cost, flexibility in materials that can be patterned, etc.) in using less conventional, non-photolithographic methods. Several such techniques (e.g. ink-jet printing [8‐10] or screen printing [11‐13] ) now appear to be suitable for a range of fabrication tasks at scales larger than ^35‐ 100 mm. While there is speculation that the resolution of some of these methods can be improved to ^10 mm, there is no experimental evidence that any of them work reliably at scales of even ^20 mm, a factor of two larger than the critical dimensions (typically transistor channel lengths) needed for realistic applications of known materials. To address this problem, we recently demonstrated a fabrication strategy that combined an emerging high resolution technique (micromolding in capillaries [14] ) for defining critical features and an established low resolution method (screen printing) for patterning other elements of the devices. [15] We used this approach to produce organic transistors with channel lengths (^2 mm) comfortably smaller than those required for most important applications. We are currently working to improve the speed and flexibility of this technique, and to explore other methods that combine and match new specialized techniques with existing ones to yield a system that can pattern, in a rapid, low cost fashion, conducting elements with a resolution of at least 5‐10 mm, and dielectrics, semiconductors, conductors, and electroluminescent materials on scales of 30‐100 mm. Here we describe microcontact printing [16] and an upside-down fabrication sequence as components of a potentially useful route for manufacturing organic electronic devices. In this approach, microcontact printing first patterns source and drain electrodes and the appropriate interconnections at a resolution of ^1 mm; the remaining components of the device (i.e. semiconductor, interlayer dielectric, and gate electrodes) are then patterned on top of these electrodes using low resolution techniques. (In the more typical rightside-up sequence, formation of source/drain electrodes occurs on top of the dielectric and gate layers.) We believe that this new strategy has many characteristics necessary for the type of rapid, large volume reel-to-reel processing that is considered important for cost effectively exploiting organics in microelectronics. The fabrication begins with microcontact printing, a technique that uses elastomeric stamps and inks to print patterns of self-assembled monolayers (SAMs) that can then be used as resists to prevent removal of material or as initiators to guide material deposition. [17,18] This technique

Strong approximations for Markovian service networks

Abstract: Inspired by service systems such as telephone call centers, we develop limit theorems for a large class of stochastic service network models. They are a special family of nonstationary Markov processes where parameters like arrival and service rates, routing topologies for the network, and the number of servers at a given node are all functions of time as well as the current state of the system. Included in our modeling framework are networks of M_t/M_t/n_t queues with abandonment and retrials. The asymptotic limiting regime that we explore for these networks has a natural interpretation of scaling up the number of servers in response to a similar scaling up of the arrival rate for the customers. The individual service rates, however, are not scaled. We employ the theory of strong approximations to obtain functional strong laws of large numbers and functional central limit theorems for these networks. This gives us a tractable set of network fluid and diffusion approximations. A common theme for service network models with features like many servers, priorities, or abandonment is “non-smooth” state dependence that has not been covered systematically by previous work. We prove our central limit theorems in the presence of this non-smoothness by using a new notion of derivative.

Semiconductor liquid junction solar cells based on anodic sulphide films

Abstract: ALTHOUGH good performance has been achieved with established solid state junction solar cells, their cost remains well above that required for large scale terrestrial applications. New concepts1,2 for photovoltaic energy conversion have been introduced which involve the junction between a semiconductor and an electrolyte. These schemes may lead to new possibilities of considerably reduced materials and fabrication costs, providing that many technical problems could be solved. We report here metal–semiconductor–liquid electrolyte junctions in which an n-type sulphide semiconductor is anodically formed in situ on its metal and, under photoexcitation, drives a sulphide–polysulphide redox couple when connected to a suitable cathode. The original contribution in this area was made by Gerischer2 who demonstrated that the cell (single crystal n-CdS/Fe(CN)64−, Fe(CN)63−/SnO2) has an initial conversion efficiency > 5% (ref. 3) for sunlight to electric power, in spite of the 2.4-eV band gap of CdS, which implies that wavelengths > 550 nm (the greater part of the incident solar photons) are ineffective.

System and method of capturing encoded data transmitted over a communications network in a video system

Abstract: A video system that captures telephone number data encoded into video signals transmitted over a video network to at least one display device is disclosed. Video signals are received that contain an escape sequence demarcating telephone number data. The system identifies the escape sequence, and captures the telephone number data. Upon command, dialing data corresponding to the telephone number data are transmitted over a telephone network to initiate a telephone call to the desired party.

Guidelines for etching silicon MEMS structures using fluorine high-density plasmas at cryogenic temperatures

Abstract: This paper presents guidelines for the deep reactive ion etching (DRIE) of silicon MEMS structures, employing SF/sub 6//O/sub 2/-based high-density plasmas at cryogenic temperatures. Procedures of how to tune the equipment for optimal results with respect to etch rate and profile control are described. Profile control is a delicate balance between the respective etching and deposition rates of a SiO/sub x/F/sub y/ passivation layer on the sidewalls and bottom of an etched structure in relation to the silicon removal rate from unpassivated areas. Any parameter that affects the relative rates of these processes has an effect on profile control. The deposition of the SiO/sub x/F/sub y/ layer is mainly determined by the oxygen content in the SF/sub 6/ gas flow and the electrode temperature. Removal of the SiO/sub x/F/sub y/ layer is mainly determined by the kinetic energy (self-bias) of ions in the SF/sub 6//O/sub 2/ plasma. Diagrams for profile control are given as a function of parameter settings, employing the previously published "black silicon method". Parameter settings for high rate silicon bulk etching, and the etching of micro needles and micro moulds are discussed, which demonstrate the usefulness of the diagrams for optimal design of etched features. Furthermore, it is demonstrated that in order to use the oxygen flow as a control parameter for cryogenic DRIE, it is necessary to avoid or at least restrict the presence of fused silica as a dome material, because this material may release oxygen due to corrosion during operation of the plasma source. When inert dome materials like alumina are used, etching recipes can be defined for a broad variety of microstructures in the cryogenic temperature regime. Recipes with relatively low oxygen content (1-10% of the total gas volume) and ions with low kinetic energy can now be applied to observe a low lateral etch rate beneath the mask, and a high selectivity (more than 500) of silicon etching with respect to polymers and oxide mask materials is obtained. Crystallographic preference etching of silicon is observed at low wafer temperature (-120/spl deg/C). This effect is enhanced by increasing the process pressure above 10 mtorr or for low ion energies (below 20 eV).