In an effort to address the need for robust optical chip I/O interconnects, we describe the fabrication and testing of microscopic polymer pillars for use as a flexible optical bridge between the chip and the substrate. The polymer pillars are photoimaged using the polymer Avatrel to a height of up to 350 μm. The photodefinable polymer Avatrel was used for the fabrication of the optical pillars due to its ease of processing and its unique material properties that include high Tg and low modulus. To evaluate the performance of the polymer pillars, the optical coupling efficiency from a light source to an optical aperture with and without an optical pillar is measured. For a light source with 12o beam divergence, a 30×150 μm polymer pillar improves the coupling efficiency by 3 to 4.5 dB compared to pillar-free (free-space) optical coupling. Due to the high mechanical compliance of the optical pillars, we also demonstrate that polymer pillars enhance the optical coupling efficiency between the chip and the substrate when they are misaligned in the lateral direction and that the displacement tolerance can be doubled from 15 to 30 μm for a 1dB power loss budget.

In recent years, thin-film photovoltaic companies started realizing their low manufacturing cost potential, and have been grabbing an increasingly larger market share. Copper Indium Gallium Selenide (CIGS) is the most promising thin-film PV material, having demonstrated the highest energy conversion efficiency in both cells and modules. However, most CIGS manufacturers still face the challenge of delivering a reliable and rapid manufacturing process that can scale effectively and deliver on the promise of this material system. HelioVolt has developed a reactive transfer process for CIGS absorber formation that has the benefits of good compositional control, and a fast high-quality CIGS reaction. The reactive transfer process is a two stage CIGS fabrication method. Precursor films are deposited onto substrates and reusable cover plates in the first stage, while in the second stage the CIGS layer is formed by rapid heating with Se confinement. HelioVolt also developed best-in-class packaging technologies that provide unparalleled environmental stability. High quality CIGS films with large grains were fabricated on the production line, and high-performance high-reliability monolithic modules with a form factor of 120 cm x 60 cm are being produced at high yield and low cost. With conversion efficiency levels around 14% for cells and 12% for modules, HelioVolt is commercializing the process on its first production line with 20 MW capacity, and is planning its next GW-scale factory.

We describe thin film photovoltaic (PV) technologies that have been scaled in manufacturing, and contrast their attributes and how they impact the levelized cost of electricity (LCOE). The thin film PV technologies reviewed include cadmium telluride (CdTe), copper indium gallium selenide (CIGS), amorphous silicon (a-Si), and microcrystalline/amorphous silicon (mu/a-Si) produced by a variety of methods. The factors studied include conversion efficiency, energy yield under different lighting and environmental conditions, location dependence, tracked/fixed tilt differential performance, uptime, output degradation rate, failure rate, lifetime, module cost, balance of system (BOS) and inverter cost, installation cost, land cost, operation cost, maintenance cost and finance cost. These thin film PV technologies are compared with crystalline silicon, the most widely deployed PV technology.

We describe nanotechnologies that improve the conversion efficiency of solar energy into electricity, and enhance the round-trip efficiency of energy storage systems. We describe nanostructures that enhance light concentration, light trapping, photon absorption, charge generation, carrier multiplication, hot electron extraction, charge transport, and current collection in photovoltaic systems, as well as nanomaterials that enhance the efficiency of electrochemical processes, boost gravimetric and volumetric energy densities, reduce the rate of self-discharge, increase the peak power rating, and extend the cycle life of secondary batteries.

Addressing the growing demand for larger capacity in information technology, VLSI Micro- and Nanophotonics: Science, Technology, and Applications explores issues of science and technology of micro/nano-scale photonics and integration for broad-scale and chip-scale Very Large Scale Integration photonics. This book is a game-changer in the sense that it is quite possibly the first to focus on "VLSI Photonics". Very little effort has been made to develop integration technologies for micro/nanoscale photonic devices and applications, so this reference is an important and necessary early-stage perspective on this field. New demand for VLSI photonics brings into play various technological and scientific issues, as well as evolutionary and revolutionary challengesall of which are discussed in this book. These include topics such as miniaturization, interconnection, and integration of photonic devices at micron, submicron, and nanometer scales. With its "disruptive creativity" and unparalleled coverage of the photonics revolution in information technology, this book should greatly impact the future of micro/nano-photonics and IT as a whole. It offers a comprehensive overview of the science and engineering of micro/nanophotonics and photonic integration. Many books on micro/nanophotonics focus on understanding the properties of individual devices and their related characteristics. However, this book offers a full perspective from the point of view of integration, covering all aspects of benefits and advantages of VLSI-scale photonic integrationthe key technical concept in developing a platform to make individual devices and components useful and practical for various applications.

Addressing the growing demand for larger capacity in information technology, VLSI Micro- and Nanophotonics: Science, Technology, and Applications explores issues of science and technology of micro/nano-scale photonics and integration for broad-scale and chip-scale Very Large Scale Integration photonics. This book is a game-changer in the sense that it is quite possibly the first to focus on "VLSI Photonics". Very little effort has been made to develop integration technologies for micro/nanoscale photonic devices and applications, so this reference is an important and necessary early-stage perspective on this field. New demand for VLSI photonics brings into play various technological and scientific issues, as well as evolutionary and revolutionary challenges—all of which are discussed in this book. These include topics such as miniaturization, interconnection, and integration of photonic devices at micron, submicron, and nanometer scales. With its "disruptive creativity" and unparalleled coverage of the photonics revolution in information technology, this book should greatly impact the future of micro/nano-photonics and IT as a whole. It offers a comprehensive overview of the science and engineering of micro/nanophotonics and photonic integration. Many books on micro/nanophotonics focus on understanding the properties of individual devices and their related characteristics. However, this book offers a full perspective from the point of view of integration, covering all aspects of benefits and advantages of VLSI-scale photonic integration—the key technical concept in developing a platform to make individual devices and components useful and practical for various applications.

L'invention concerne des precurseurs liquides contenant de l'indium et du selenium adaptes pour le depot sur un substrat, afin de former des films minces adaptes pour des applications de semi-conducteurs. L'invention concerne egalement des procedes de preparation de ces precurseurs liquides et un procede de depot d'un precurseur liquide sur un substrat.

Harnessing solar energy has increased tremendously in recent years as the importance of renewable energy has moved to the forefront of social consciousness. Thin-film photovoltaic (PV) technologies have attracted much attention, because they offer a distinct cost advantage. Copper indium gallium selenide (CIGS) is the most promising material for such applications, because it has the highest energy-conversion efficiency of any thin film: 20.3% for cells1 and 15.1% for modules.2 However, it has been challenging to reliably and rapidly produce CIGS films on scale. To address this problem, we developed a reactive transfer process that benefits from good compositional control and fast, high-quality reaction over large areas. We also developed packaging technologies that provide high environmental stability. Our reactive transfer process can form CIGS films on a variety of materials, including glass and various metals and plastics. Our monolithic interconnection scheme involves three main patterning steps, including laser and mechanical scribing. After initial sputtering of a molybdenum back-contact film and laser patterning, a two-stage reactive transfer process forms a high-performance, thin-film CIGS absorber layer (see Figure 1).3 In the first stage, copper, indium, gallium, and seleniumbased precursor films are deposited onto the substrate and cover plate. This film stack allows precise control of the composition and crystalline structure of the resulting CIGS film. The film stack also permits different modes of processing, for example, physical vapor deposition and liquid-precursor spray printing.4 Furthermore, precursors can be deposited at low substrate temperatures, thus lowering cost and increasing throughput. In the second stage, the precursors rapidly react under pressure, with the plates held in close proximity and the precursor-film stacks facing each other. In the vapor phase, a controlled amount of Figure 1. Two-stage reactive transfer process for producing photovoltaic copper indium gallium selenide (CIGS) film. Cu: Copper. In: Indium. Ga: Gallium. Se: Selenium.

A wide array of nanotechnologies can be used to improve the efficiency of energy harvest from the Sun and the wind, and the efficiency of energy storage in secondary batteries, for use in smart grid and transportation applications. High-quality nanostructured copper indium gallium selenide thin films help produce high-efficiency photovoltaic modules. Various nanotechnologies are utilized to improve the efficiency of power-generating wind turbines, including nanoparticle-containing lubricants that reduce the friction generated from the rotation of the turbines, nanocoatings for de-icing and self-cleaning technologies, and advanced nanocomposites that provide lighter and stronger wind blades. A number of nanotechnologies can be beneficial in advanced high-capacity secondary batteries for smart grid and transportation applications. These technologies include nanostructured carbon-nanotube-based and silicon-nanowire-based electrodes with ultrahigh surface areas, as well as nanoengineered beta-alumina ceramic electrolytes with well-controlled grains, grain boundaries, and crystal orientation, which are used to boost the energy and power densities in secondary batteries such as lithium-ion, sodium-sulfur, flow, and dry cell batteries. (C) 2011 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.3574149]