PARC , formerly Xerox PARC, is a research and development company in Palo Alto, California, with a distinguished reputation for its contributions to information technology and hardware systems.Founded in 1970 as a division of Xerox Corporation, PARC has been responsible for such well known and important developments as laser printing, Ethernet, the modern personal computer, graphical user interface and desktop paradigm, object-oriented programming, ubiquitous computing, amorphous silicon applications, and advancing very-large-scale-integration for semiconductors.Xerox formed Palo Alto Research Center Incorporated as a wholly owned subsidiary in 2002. Wikipedia.
Arias A.C.,Palo Alto Research Center PARC |
MacKenzie J.D.,Green Hills |
McCulloch I.,Imperial College London |
Rivnay J.,Stanford University |
Salleo A.,Stanford University
Chemical Reviews | Year: 2010
The synthesis, processing, and device performance of polymeric semiconductors has been reported. The polysilicon TFT technology is used for active matrix organic light-emitting diode (AMOLED) as the higher carrier mobilities of polysilicon as compared to a-Si, and increased stability of polysilicon-based devices under bias stress, are more effective in AMOLED. The radio frequency (RF) wireless applications are required in large area, self-powered, or maximized range device is partially driven by the fundamental physics of the frequency regimes in which they operate. Large area, high throughput manufacturing of organic electronic roducts is most efficiently enabled by solution based, additive printing techniques. Regioregular (RR) poly(3-hexylthiophene) (P3HT) is an exemplary semiconducting polymer due to its ready availability, ease of processing from solution, and its promising electrical properties arising from a highly crystalline microstructure.
Street R.A.,Palo Alto Research Center PARC
Physical Review B - Condensed Matter and Materials Physics | Year: 2010
The Comment by Deibel and Wagenpfahl concerning recombination in organic bulk heterojunction solar cells is discussed. A simple transport and recombination model supports our previous conclusion that the bias dependence of the cell photocurrent correctly identifies the recombination kinetics, and that at low illumination intensity the recombination is first order. The analysis suggests that the two points of view may be reconciled. The experimental evidence for bimolecular recombination and some general aspects of recombination are discussed. © 2010 The American Physical Society.
Saund E.,Palo Alto Research Center PARC
IEEE Transactions on Pattern Analysis and Machine Intelligence | Year: 2013
Effective object and scene classification and indexing depend on extraction of informative image features. This paper shows how large families of complex image features in the form of subgraphs can be built out of simpler ones through construction of a graph lattice - a hierarchy of related subgraphs linked in a lattice. Robustness is achieved by matching many overlapping and redundant subgraphs, which allows the use of inexpensive exact graph matching, instead of relying on expensive error-tolerant graph matching to a minimal set of ideal model graphs. Efficiency in exact matching is gained by exploitation of the graph lattice data structure. Additionally, the graph lattice enables methods for adaptively growing a feature space of subgraphs tailored to observed data. We develop the approach in the domain of rectilinear line art, specifically for the practical problem of document forms recognition. We are especially interested in methods that require only one or very few labeled training examples per category. We demonstrate two approaches to using the subgraph features for this purpose. Using a bag-of-words feature vector we achieve essentially single-instance learning on a benchmark forms database, following an unsupervised clustering stage. Further performance gains are achieved on a more difficult dataset using a feature voting method and feature selection procedure. © 1979-2012 IEEE.
Street R.A.,Palo Alto Research Center PARC
Physical Review B - Condensed Matter and Materials Physics | Year: 2011
Transient photocurrent (TPC) and transient photovoltage (TPV) measurements are reported in bulk heterojunction organic solar cells. TPC is used to measure the band tail and deep trap density of states within the interface band gap and to identify the carrier species from the relative contribution of drift and diffusion. Steep exponential band tails are observed near the donor valence band edge, changing to a broader distribution of states at larger trap energies. The effect of the localized state distribution on the recombination is analyzed-particularly for geminate recombination, where it is shown that band tails can substantially enhance the probability that geminate pairs ionize to form free carriers. The TPV response is shown to have completely different characteristics from those of TPC, and the explanation is provided. © 2011 American Physical Society.
Palo Alto Research Center PARC | Date: 2015-08-17
A vertical external cavity surface emitting laser (VECSEL) structure includes a heterostructure and first and second reflectors. The heterostructure comprises an active region having one or more quantum well structures configured to emit radiation at a wavelength,