%0 Report %D 2014 %T COMFEN – Early Design Tool for Commercial Facades and Fenestration Systems %A Stephen E. Selkowitz %A Robert J. Hitchcock %A Robin Mitchell %A Maurya McClintock %A Kevin Settlemyre %X

California leads the nation in building energy efficiency standards and is a leader in the United States for legislation to reduce greenhouse gas emissions. Achieving these goals in practice requires that design teams and owners have access to technologies, systems and decision support tools that support their design work. This California Energy Commission funded work on the COMFEN software tool, which gives building practitioners, such as architects and engineers, the ability to assess the energy consequences of building design decisions, is thus a key enabling element that supports the AEC community in achieving ever more stringent performance requirements. COMFEN can provide needed building design guidance to not achieve the shorter term code goals but supports more aggressive achievement of the net-zero energy performance and peak load reduction required for all new buildings by 2030 as well as supporting deep retrofit of existing building stock.

Achieving a net-zero energy building cannot be done solely by improving the efficiency of the engineering systems (HVAC, lighting, equipment). It also requires consideration of the essential nature of the building starting early in the design process, including factors such as architectural form, massing, orientation and enclosure. Making informed decisions about the fundamental character of a building requires continuous assessment of the effects of the complex interaction of these factors on the resulting performance of the building as the design evolves. The complexity of these interactions necessitates the use of modeling and simulation tools to dynamically analyze the effects of the relationships. Decisions about the building fundamentals are often made in the earliest stages of design, before a complete 'building' exists to model so that a focus on representative spaces in the building allows earlier guidance for the decision making.

COMFEN, an early-design energy modeling tool developed by LBNL, is designed specifically to make informed decisions about building fundamentals by considering the design of the building envelope, orientation and massing on building performance. It supports exploratory work early in the process by architects but is also useful for engineers and consultants later in the design process. It also supports innovation broadly as it allows teams to model new technologies and systems that are becoming available but have not yet reached mainstream status.

COMFEN focuses on the concept of a "space" or "room" and uses the EnergyPlus and Radiance™ engines and a simple, graphic user interface to allow the user to explore the effects of changing key early-design input variables for the façade, internal loads, lighting controls and HVAC system on energy consumption, peak energy demand, and thermal and visual comfort. COMFEN also provides the ability to import glazing systems that have been developed in Window7, utilizing the International Glazing DataBase (IGDB) for glass choices. Comparative results are rapidly presented in a variety of graphic and tabular formats to help users move toward optimal façade and fenestration design choices.

While the underlying simulation engines were developed over time as part of DOE's national windows and daylighting program, the specific design features of COMFEN were evolved over a several year period by consulting with a series of largely California-based architectural and engineering firms who provided important guidance and feedback on desirable features and then on functionality once the features were implemented.

COMFEN is available at no charge on the LBNL website.

%8 03/2014 %0 Book Section %B EnergyPlus Engineering Reference %D 2013 %T Complex Fenestration Calculation Module %A Joseph H. Klems %X

This document is organized to give you the best possible look into the EnergyPlus calculations. First, the concepts of modeling in EnergyPlus are presented. These include descriptions of the zone heat balance process, air loop/plant loop processes as well as other important processes for the building simulation.

Discussions during the modeling process may reference specific "object names" as found in the Input/Output Reference document.

The remainder of the document focuses on individual models.

%B EnergyPlus Engineering Reference %8 10/2013 %& Window Calculation Module %0 Report %D 2012 %T Conditioning anisotropic BSDF measurements for lighting and daylighting simulation %A Gregory J. Ward %X

This report describes the requirements for utilizing bidirectional scattering distribution function (BSDF) measurements produced by the PAB-Opto goniophotometer and similar devices in simulation tools such as Radiance, and describes progress to date in implementing these methods. An interpolation technique has been identified for resampling the measured data, and an initial implementation has been produced. Work continues on improving this technique and software so it may be employed in a streamlined process for reducing BSDF measurements to a usable form and distributed as variable-resolution XML data. This data may then be employed by lighting simulation software to model complex fenestration systems.

%C Berkeley %8 09/2012 %G eng %9 DOE/ LBNL FY12 Technical Report Deliverable %0 Conference Paper %B Building Enclosure Sustainability Symposium (BESS), April 29-30, 2011 %D 2011 %T COMFEN 3.0: Evolution of an Early Design Tool for Commercial Façades and Fenestration Systems %A Stephen E. Selkowitz %A Robin Mitchell %A Maurya McClintock %A Daniel McQuillen %A Andrew McNeil %A Mehry Yazdanian %X

Achieving a net-zero energy building cannot be done solely by improving the efficiency of the engineering systems. It also requires consideration of the essential nature of the building including factors such as architectural form, massing, orientation and enclosure. Making informed decisions about the fundamental character of a building requires assessment of the effects of the complex interaction of these factors on the resulting performance of the building. The complexity of these interactions necessitates the use of modeling and simulation tools to dynamically analyze the effects of the relationships, yet decisions about the building fundamentals are often made in the earliest stages of design, before a 'building' exists to model.

To address these issues, Lawrence Berkeley National Laboratory (LBNL) has developed an early-design energy modeling tool (COMFEN) specifically to help make informed decisions about building façade fundamentals by considering the design of the building envelope, orientation and massing on building performance. COMFEN focuses on the concept of a "space" or "room" and uses the EnergyPlus, and Radiance™ engines and a simple, graphic user interface to allow the user to explore the effects of changing key early-design input variables on energy consumption, peak energy demand, and thermal and visual comfort. Comparative results are rapidly presented in a variety of graphic and tabular formats to help users move toward optimal façade and fenestration design choices.

While COMFEN 1.0 utilized an Excel™–based user interface, COMFEN 3.0 has been reworked to include a simple, more intuitive, yet powerful Graphic User Interface (GUI), a broader range of libraries for associated system and component choices and deliver a wider range of graphic outputs and options.

This paper (and presentation) outlines the objectives in developing and further refining COMFEN, the mechanics of the program, and plans for future development. 

%B Building Enclosure Sustainability Symposium (BESS), April 29-30, 2011 %C Pomona, CA %8 03/2011 %G eng %1

Windows and Daylighting Group

%2 LBNL-5179E %0 Report %D 2011 %T Computing and applying variable-resolution data for bidirectional scattering distribution functions %A Gregory J. Ward %X

We introduce the Tensor Tree representation for bidirectional scattering distribution functions (BSDFs), a variable-resolution data structure designed to minimize storage and computation. We offer a method for reducing full-resolution BSDF data into this format, and relate techniques for the efficient generation of uniformly weighted Monte Carlo samples. The Tensor Tree BSDF representation has been tested and incorporated into the 4.1 release of LBNL's Radiance lighting simulation and rendering system, with additional methods for modeling the appearance of complex fenestration systems. Finally, an independent software library is described for third-party developers who wish to support BSDF data outside of Radiance, and recommendations are made for future development directions.

%8 09/2011 %G eng %9 DOE Technical Report %0 Conference Paper %B Third ACM Workshop on Embedded Sensing Systems for Energy-Efficiency in Buildings %D 2011 %T Co-simulation based building controls implementation with networked sensors and actuators %A Yao-Jung Wen %A Dennis L. DiBartolomeo %A Francis M. Rubinstein %Y Ruzzelli, Antonio %X

The commercial building sector is one of the largest energy consumers in the U.S., and lighting, heating, ventilating and air conditioning contribute to more than half of the energy consumption and carbon emissions in buildings. Controls are the most effective way of increasing energy efficiency in building systems; however, the interdependencies among building subsystems must be taken into account to achieve deep energy savings. A networked sensing and actuation infrastructure shared among building systems is the key to optimal integrated control of the interdependent building elements in low energy and zero net energy buildings.

This paper presents a rapid-prototyping controls implementation platform based on the Building Controls Virtual Test Bed (BCVTB) framework that is capable of linking to building sensor and actuator networks for efficient controller design and testing. The platform creates a separation between the controls and the physical systems so that the controller can easily be implemented, tested and tuned with real performance feedback from a physical implementation. We realized an integrated lighting control algorithm using such a rapid-prototyping platform in a testing facility with networked sensors and actuators. This implementation has demonstrated an up to 57% savings in lighting electricity and 28% reduction in cooling demand.

%B Third ACM Workshop on Embedded Sensing Systems for Energy-Efficiency in Buildings %I ACM Press %C Seattle, Washington %V Proceedings of BuildSys 2011 %P 55 %8 11/2011 %@ 9781450307499 %! BuildSys '11 %R 10.1145/2434020.2434040 %0 Report %D 2007 %T Commissioning and verification procedures for the automated roller shade system at The New York Times Headquarters %A Eleanor S. Lee %A Robert D. Clear %A Gregory J. Ward %A Luis L. Fernandes %X

This document describes the procedures for verification testing of a newly installed automated roller shade system. The automated roller shade system has been designed to control direct sun and window glare while admitting daylight and permitting view out. Procedures in this document focus on verifying that the glare control aspect of this commercially-available system works prior to building occupancy. A high dynamic range luminance measurement tool, developed for this project, is used to verify that the average window luminance is within acceptable limits. Additional spreadsheet and visualization tools are described. The commissioning agent (CxA) and The New York Times will use these procedures during the commissioning phase of the building to verify that the automated control system is operating as intended.

%C Berkeley %8 05/2007 %0 Journal Article %J Journal of Applied Physics %D 2004 %T Charge-State-Resolved Ion Energy Distributions of Aluminum Vacuum Arcs %A Johanna Rosén %A André Anders %A Stanislav Mráz %A Jochen M. Schneider %X

The charge-state-resolved ion energy distributions of metal ions present in a cathodic arc plasma have been measured and analyzed. Contrary to literature data, lower energies were observed for higher charged ions. The observations were explained by opposing acceleration by pressure gradient and electron-ion coupling, and deceleration by part of the discharge voltage. The distributions were well fitted by shifted Maxwellian distributions, giving additional information on plasma parameters. These results are of importance for an improved understanding of the evolution of ion energy distributions, and is hence instrumental for future progress in thin film growth modelling.

%B Journal of Applied Physics %V 97 %G eng %1

Windows and Daylighting Group

%2 LBNL-56327 %0 Journal Article %J Applied Physics Letters %D 2003 %T Coalescence of Nanometer Silver Islands on Oxides Grown by Filtered Cathodic Arc Deposition %A Eungsun Byon %A Thomas W.H. Oates %A André Anders %X

Ultrathin silver films have been deposited on glass and oxide-coated glass using filtered cathodic arc deposition and, for comparison, magnetron sputtering. The energetic differences between these deposition methods lead to initially different film properties. Silver films made by cathodic arc deposition show an earlier onset of island coalescence, indicating a lower aspect ratio than islands produced by evaporation and sputtering. However, the as-deposited films are thermodynamically unstable, exhibiting changes on a timescale of minutes. While films of islands tend to increase their sheet resistance with time, the sheet resistance of contiguous films shows a decrease. Both effects can be explained by silver mobility driven to minimize film and interfacial energy.

%B Applied Physics Letters %V 82 %P 1634-1636 %G eng %U http://dx.doi.org/10.1063/1.1558955 %1

Windows and Daylighting Group

%2 LBNL-51307 %! Appl. Phys. Lett. %& 1634 %0 Journal Article %J Solar Energy %D 2003 %T Comparison Between Ray-Tracing Simulations and Bi-Directional Transmission Measurements on Prismatic Glazing %A Marilyn Andersen %A Michael D. Rubin %A Jean-Louis Scartezzini %X

Evaluation of solar heat gain and daylight distribution through complex window and shading systems requires the determination of the bi-directional transmission distribution function (BTDF). Measurement of BTDF can be timeconsuming, and inaccuracies are likely because of physical constraints and experimental adjustments. A general calculation methodology, based on more easily measurable component properties, would be preferable and would allow much more flexibility. In this paper, measurements and calculations are compared for the specific case of prismatic daylight-redirecting panels. Measurements were performed in a photogoniometer equipped with a digital-imaging detection system. A virtual copy of the photogoniometer was then constructed with commercial ray-tracing software. For the first time, an attempt is made to validate detailed bi-directional properties for a complex system by comparing an extensive set of experimental BTDF data with ray-tracing calculations. The results generally agree under a range of input and output angles to a degree adequate for evaluation of glazing systems. An analysis is presented to show that the simultaneously measured diffuse and direct components of light transmitted by the panel are properly represented. Calculations were also performed using a more realistic model of the source and ideal model of the detector. Deviations from the photogoniometer model were small and the results were similar in form. Despite the lack of an absolute measurement standard, the good agreement in results promotes confidence in both the photogoniometer and in the calculation method. 

%B Solar Energy %V 74 %P 157-173 %8 02/2003 %G eng %N 2 %1

Windows and Daylighting Group

%2 LBNL-51169 %& 157 %R 10.1016/S0038-092X(03)00115-4 %0 Journal Article %J Journal of Applied Physics %D 2002 %T Calculation of Thermodynamic, Electronic, and Optical Properties of Monoclinic Mg2NiH4 %A Whittier R. Myers %A Lin-Wang Wang %A Thomas J. Richardson %A Michael D. Rubin %X

Ab initio total-energy density functional theory is used to investigate the low temperature (LT) monoclinic form of Mg2NiH4. The calculated minimum energy geometry of LT Mg2NiH4 is close to that determined from neutron diffraction data, and the NiH4 complex is close to a regular tetrahedron. The enthalpies of the phase change to high temperature (HT) pseudo-cubic Mg2NiH4 and of hydrogen absorption by Mg2Ni are calculated and compared with experimental values. LT Mg2NiH4 is found to be a semiconductor with an indirect band gap of 1.4 eV. The optical dielectric function of LT Mg2NiH4 differs somewhat from that of the HT phase. A calculated thin film transmittance spectrum is consistent with an experimental spectrum.

%B Journal of Applied Physics %V 91 %P 4879-4885 %8 04/2002 %G eng %N 8 %1

Windows and Daylighting Group

%2 LBNL-47519 %& 4879 %R 10.1063/1.1454206 %0 Report %D 2002 %T A Characterization of the Nonresidential Fenestration Market %A Arman Shehabi %A Charles N. Eley %A Dariush K. Arasteh %A Phil Degens %X

The purpose of this report is to characterize the nonresidential fenestration market in order to better understand market barriers to, and opportunities for, energy-efficient fenestration products. In particular, the goal is to:

The U.S. glass industry is a $27 billion enterprise with both large producers and small firms playing pivotal roles in the industry. While most sectors of the glass industry have restructured and consolidated in the past 20 years, the industry still employs 150,000 workers. Nonresidential glazing accounts for approximately 18% of overall U.S. glass production. In 1999, nonresidential glazing was supplied to approximately 2.2 billion ft2 of new construction and additions. That same year, nonresidential glazing was also supplied to approximately 1.1 billion ft2 of remodeling construction. With an industry this large and complex, it is to be expected that many market participants can influence fenestration selection. If market barriers to the selection of high performance fenestration products are better understood, then the U. S. Department of Energy (USDOE), the Northwest Energy Efficiency Alliance (NEEA), and others can develop programs and policies that promote greater energy efficiency in commercial glazing products.

%G eng %L LBNL-52699 %1

Windows and Daylighting Group

%2 LBNL-52699 %0 Conference Paper %B ASHRAE Transactions %D 1995 %T Calorimetric Measurements of Inward-Flowing Fraction for Complex Glazing and Shading Systems %A Joseph H. Klems %A Guy O. Kelley %X

This paper presents a calorimetric measurement of layer-specific inward-flowing fractions of absorbed solar energy for a number of geometric configurations common in fenestrations with shading. The inward-flowing fractions are found to be relatively insensitive to exterior conditions. Results for an interior venetian blind over double glazing agree with thermal model calculations in the literature, and are the first layer-specific verification of these calculations. It is argued that a data base of these inward-flowing fractions for a suitably broad class of geometries will make possible the determination of solar heat gain coefficient from non-calorimetric measurements of solar-optical properties of complex fenestration components, a procedure termed solar-thermal separation.

%B ASHRAE Transactions %V 102, Part 1 %G eng %L LBL-37038 %1

Windows and Daylighting Group

%2 LBL-37038 %0 Conference Paper %B Proceedings of Window Innovations Conference 95 %D 1995 %T Chromogenic Switchable Glazing: Towards the Development of the Smart Window %A Carl M Lampert %X

The science and technology of chromogenic materials for switchable glazings in building applications is discussed. These glazings can be used for dynamic control of solar and visible energy. Currently many researchers and engineers are involved with the development of products in this field. A summary of activities in Japan, Europe, Australia, USA and Canada is made. The activities of the International Energy Agency are included. Both non-electrically activated and electrically activated glazings are discussed. Technologies covered in the first category are photochromics, and thermochromics and thermotropics. A discussion of electrically activated chromogenic glazings includes dispersed liquid crystals, dispersed particles and electrochromics. A selection of device structures and performance characteristics are compared. A discussion of transparent conductors is presented. Technical issues concerning large-area development of smart windows are discussed.

%B Proceedings of Window Innovations Conference 95 %C Toronto, Canada %8 06/1995 %G eng %L LBL-37766 %1

Windows and Daylighting Group

%2 LBL-37766 %0 Conference Paper %B ASHRAE Transactions %D 1995 %T A Comparison Between Calculated and Measured SHGC For Complex Fenestration Systems %A Joseph H. Klems %A Jeffrey L. Warner %A Guy O. Kelley %X

Calorimetric measurements of the dynamic net heat flow through a complex fenestration system consisting of a buff venetian blind inside clear double glazing are used to derive the direction-dependent beam SHGC of the fenestration. These measurements are compared with calculations according to a proposed general method for deriving complex fenestration system SHGCs from bidirectional layer optical properties and generic calorimetric properties. Previously published optical measurements of the same venetian blind and generic inward-flowing fraction measurements are used in the calculation. The authors find satisfactory agreement between the SHGC measurements and the calculation.

Significant dependence on incident angle was found in the measured SHGCs. Profile angle was not found to be a useful variable in characterizing the system performance. The predicted SHGC was found to be inherently dependent on two angles, although only the incident angle variations were observable under the test conditions.

%B ASHRAE Transactions %C Atlanta, GA %V 102, Part 1 %8 02/1996 %G eng %L LBL-37037 %1

Windows and Daylighting Group

%2 LBL-37037 %0 Journal Article %J Solar Energy Materials and Solar Cells %D 1994 %T Characterization of Sol-Gel Deposited Niobium Pentoxide Films for Electrochromic Devices %A Nilgün Özer %A Timothy Barreto %A Temel Buyuklimanl %A Carl M Lampert %X

Niobium pentoxide films, fabricated by the sol-gel process, were spin coated onto conductive indium tin oxide (ITO)/glass, and microscope slides. These films were cycled in a 1M LiClO4 propylene carbonate (PC) solution, and exhibited electrochromic behavior upon the electrochemical insertion (reduction) and extraction (oxidation) of lithium. In-situ optical transmittance measurements were investigated in the ultraviolet/visible/near-infrared wavelength regions (250-2100 nm). Niobium pentoxide films showed reversible optical switching from 320 to 870 nm, but were found electrochromically inactive in the infrared region. Surface analysis using X-ray photoelectron spectroscopy (XPS) indicated little difference in the chemistry of Nb2O5 films as deposited and lithiated LixNb2O5 films, as XPS binding energies of Nb and O showed no appreciable shifts. These films were found to be amorphous by X-ray diffraction. Optical transmittance measurements combined with cyclic voltamograms and XPS spectra, revealed that the electrochromic behavior of these films occurs due to the insertion of Li+ cations into niobium pentoxide films. The bronze coloration of the niobium pentoxide films could make them useful as an electrochromic counter electrodesfor electrochromic devices.

%B Solar Energy Materials and Solar Cells %V 36 %P 433-443 %G eng %L LBL-38525 %1

Windows and Daylighting Group

%2 LBL-38525 %0 Conference Paper %D 1994 %T Characterization of Tantalum Oxide Films Prepared by Sol-Gel Process for electrochemical devices %A Nilgün Özer %A Yongxiang He %A Carl M Lampert %X

Tantalum oxide films were prepared by sol-gel process using tantalum ethoxide Ta(OC2H5)5. The dependence of deposition conditions (i.e. composition of polymeric solutions and spinning rate) on ionic conductivities for tantalum oxide films were studied. The best results achieved for films fabricated by the spin coating technique were from clear polymeric solutions. These films had low packing density ρ=3.2 g/cm3 and good proton conductivity (about 10-6 Ω-1 cm-1). X-ray photoelectron spectroscopy (XPS) was used for studying the compositions of the tantalum oxide films. We report on the use of tantalum oxide films as ion conductors in devices consisting of WO3/Ta2O5/H+ ion storage polymer structure. We found tantalum oxide to have very good properties for proton device applications.

%G eng %L LBNL-39005 %1

Windows and Daylighting Group

%2 LBNL-39005 %0 Conference Paper %B ACEEE 1994 Summer Study on Energy Efficiency in Buildings %D 1994 %T A Comprehensive Approach to Integrated Envelope and Lighting Systems for New Commercial Buildings %A Eleanor S. Lee %A Stephen E. Selkowitz %A Francis M. Rubinstein %A Joseph H. Klems %A Liliana O. Beltran %A Dennis L. DiBartolomeo %X

We define a comprehensive approach to integrated envelope and lighting systems design as one that balances energy efficiency with anequal regard to the resultant environmental quality. By integrating envelope components (glazing, shading, and daylighting), lighting components (fixtures and controls) and building HVAC/ energy management control systems, we create building systems that have the potential to achieve significant decreases in electricity consumption and peak demand while satisfying occupant physiological and psychological concerns.

This paper presents results on the development, implementation, and demonstration of two specific integrated envelope and lighting systems:

  1. A system emphasizing dynamicsenvelope components and responsive electric lighting systems, that offer the potential to achieve energy efficiency goals and a near optimum comfort environment throughout the year by adapting to meteorological conditions and occupant preferences in real time, and
  2. perimeter daylighting systems that increase the depth of daylight penetration from sidelight windows and improves visual comfort with the use of a small inlet aperture.

The energy performance of the systems was estimated using the DOE-2 building energy simulation program. Field tests with reduced scale models were conducted to determine daylighting and thermal performance in real time under actual weather conditions. Demonstrations of these integrated systems are being planned or are in progress in collaboration with utility programs to resolve real-world implementation issues under complex site, building, and cost constraints. Results indicate that integrated systems offer solutions that not only achieve significant peak demand reductions but also realize consistent energy savings with added occupant comfort and satisfaction.

%B ACEEE 1994 Summer Study on Energy Efficiency in Buildings %C Pacific Grove, CA %8 09/1994 %G eng %L LBL-35732 %1

Commercial Building Systems Group

%2 LBL-35732 %0 Conference Paper %B SPIE Proceedings 2017 %D 1993 %T Characteristics of Laminated Electrochromic Devices Using Polyorganodisulfate Electrodes %A Carl M Lampert %A Steven J. Visco %A Marca M. Doeff %A Yan Ping Ma %A Yongxiang He %A Jean-Christophe Giron %X

The use of polyorganodisulfides as optically passive counterelectrodes in a variety of electrochromic devices are discussed. Characteristic data is presented for electrochmmic devices using proton, and lithium coloration ions with polyethylene oxide electrolyte and polydimercaptothiadiazole positive electrodes. Solid state devices consisting of molybdenum doped W03, amorphous polyethylene oxide electrolyte (a-PEO), and a polyorganodisulfide counter-electrode colored rapidly from a pale yellow to a deep blue-green, upon application of 1.2 V d.c. The photopic transmittance changed from 61 to 98, and the solar transmittance from 45 to 5% during the coloration process. Also, our experiments with polyimidazole are detailed. This family of compounds due to its unique electrical and ion conduction properties allow a single composite ion storage and ion conductor electrode to be made, simplifying the device construction. Devices rnade from this family of compounds color to deep blue-gray upon application of 1.2-1.5 V. Bleaching occurs at -0.4 to -0.5 s. The photopic transmittance changed from 55 to 9%. and the solar transmittance from 34 to 4% during coloration. Both coloration and bleaching are quite rapid.

%B SPIE Proceedings 2017 %P 143 %G eng %L LBL-33144 %1

Windows and Daylighting Group

%2 LBL-33144 %0 Conference Paper %B Materials Research Society %D 1993 %T Comparison of AIN Films Grown by RF at Magnetron Sputtering and Ion-Assisted Molecular Beam Epitaxy %A James S. Chan %A T.C. Fu %A Nathan W. Cheung %A Jennifer T. Ross %A Nathan Newman %A Michael D. Rubin %X

Crystalline aluminum nitride (AlN) thin films were formed on various substrates by using RF magnetron sputtering of an A1 target in a nitrogen plasma and also by ion-assisted molecular beam epitaxy (IAMBE). Basal-oriented AlN/(111) Si showed a degradation of crystallinity with increased substrate temperature from 550 to 770 °C, while the crystallinity of AlN/(0001) Al2O3 samples improved from 700 to 850 °C. The optical absorption characteristics of the AlN/(0001) Al2O3 films as grown by both deposition methods revealed a decrease in sub-band gap absorption with increased substrate temperature.

%B Materials Research Society %C San Francisco, CA %V 300 %8 04/1993 %G eng %1

Windows and Daylighting Group

%2 LBL-35660