Saxonburg, PA, United States
Saxonburg, PA, United States

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Zhou G.,Ii Vi Inc. | Wang Z.,Ii Vi Inc.
Optics InfoBase Conference Papers | Year: 2016

In this work, the film crack defect is described in details when observed during the development of an infrared film product. In consideration of the forming mechanism of film crack, DOE is conducted on different factors of material, substrate temperature and stack design, etc. Finally, the suitable design and process settings are built to eliminate film crack with the spectrum meeting customer requirements, successfully delivered infrared film products to volume production. © OSA 2016.


Trademark
Ii Vi Inc. and II VI Incorporated | Date: 2011-10-18

Optical products, namely, lenses, reflectors, mirrors, windows, beam expander-condensers, waveplates, phase retarders, polarizer-analyzer-attenuators, thin film polarizers and electro-optical modulators.


Kirkham M.J.,Oak Ridge National Laboratory | Dos Santos A.M.,Oak Ridge National Laboratory | Rawn C.J.,Oak Ridge National Laboratory | Rawn C.J.,University of Tennessee at Knoxville | And 3 more authors.
Physical Review B - Condensed Matter and Materials Physics | Year: 2012

Materials with the half-Heusler structure possess interesting electrical and magnetic properties, including potential for thermoelectric applications. MgAgSb is compositionally and structurally related to many half-Heusler materials but has not been extensively studied. This work presents the high-temperature x-ray diffraction analysis of MgAgSb between 27 and 420 ∼C, complemented with thermoelectric property measurements. MgAgSb is found to exist in three different crystal structures in this temperature region, taking the half-Heusler structure at high temperatures, a Cu 2Sb-related structure at intermediate temperatures, and a previously unreported tetragonal structure at room temperature. All three structures are related by a distorted Mg-Sb rocksalt-type sublattice, differing primarily in the Ag location among the available tetrahedral sites. Transition temperatures between the three phases correlate well with discontinuities in the Seebeck coefficient and electrical conductivity; the best performance occurs with the novel room temperature phase. For application of MgAgSb as a thermoelectric material, it may be desirable to develop methods to stabilize the room temperature phase at higher temperatures. © 2012 American Physical Society.


Wu P.,Ii Vi Inc.
Journal of Crystal Growth | Year: 2010

Extensive study of threading dislocations in 4H SiC crystals has been carried out using etching in molten KOH. In contrast to well-defined hexagonal pits formed on lightly doped 4H epilayers, etching of bulk 4H SiC crystals heavily doped with nitrogen produced rounded etch pits with their sizes varying in a wide range. Neither shape nor size of the etch pits in the bulk n+4H crystals could be used to distinguish between threading edge and treading screw dislocations. Data on the density of threading screw dislocations were obtained by counting etch pits on the carbon face of the wafers. Sequential steps of material removal, which included polishing followed by KOH etching, were used to track threading dislocations along the growth direction. It was found that a threading dislocation can produce etch pits of different sizes at different depths in the wafer. Mobility of the front of threading dislocations during growth was assessed by measuring change in the position of the dislocation etch pits upon sequential material removal. Statistical distribution of such displacements in the wafer plane was found to be lognormal. On average, the growth distance of 8 μm corresponded to the change in the etch pit position of about 2 μm. This shows that the front of threading dislocations has significant mobility during SiC sublimation growth, resulting in tilted or curved dislocation lines in the grown crystal. © 2009 Elsevier B.V. All rights reserved.


Sharp J.,Ii Vi Inc. | Bierschenk J.,Ii Vi Inc.
Journal of Electronic Materials | Year: 2015

The thermoelectric industry serves a broad range of applications using, mainly, a few standard module designs. This paper first briefly describes types of modules and two types of thermoelectric material used by the industry, after which the focus is on selected features of the standard designs and reasons for their prevalence. Whereas cost reduction and the need to maximize reliability drive the adoption of standard modules, other factors contribute to shaping the particular features of the standard thermoelectric cooling modules. These factors include the magnitude of heat loads, heat-sink performance, durability and performance expectations, and relative ease of manufacture. This discussion of the features and prevalence of standard modules relates to broader aspects of both the production and implementation of thermoelectric modules, and an estimate of current thermoelectric industry output is included. © 2014, The Minerals, Metals & Materials Society.


Gupta R.P.,Ii Vi Inc. | McCarty R.,Ii Vi Inc. | Bierschenk J.,Ii Vi Inc. | Sharp J.,Ii Vi Inc.
Materials Research Society Symposium Proceedings | Year: 2013

As thermoelectric (TE) element length decreases, the impact of contact resistance on TE device performance grows more significant. In fact, for a TE device containing 100-μm tall Bi2Te3TE elements, the figure of merit ratio (ZTDevice/ZTMaterial) drops from 0.9 to 0.5 as the contact resistivity increases from 5 × 10-01 to 5 × 10-06 Ω-cm2. To understand the effects of contact resistance on bulk TE device performance, a reliable experimental measurement method is needed. There are many popular methods to extract contact resistance such as Transmission Line Measurements (TLM) and Kelvin Cross Bridge Resistor method (KCBR), but they are only well-suited for measuring metal contacts on thin films and do not necessarily translate to measuring contact resistance on bulk thermoelectric materials. The authors present a new measurement technique that precisely measures contact resistance (on the order of 5 × 10-07 Ω-cm2) on bulk thermoelectric materials by processing stacks of bulk, metal-coated TE wafers using TE industry standard processes. One advantage of this technique is that it exploits realistic TE device manufacturing techniques and results in an almost device-like structure, therefore representing a realistic value for electrical contact resistance in a bulk TE device. Contact resistance measurements for metal contacts to n- and p-type Bi2Te3 alloys are presented and an estimate of the accuracy of the measurements is discussed. © 2013 Materials Research Society.


Trademark
Ii Vi Inc. | Date: 2016-09-28

Optical components and products for use with lasers, namely, lenses, partial reflectors, beamsplitters, mirrors; optical glass, nozzles, beam expander-condensers, waveplates, reflective phase retarders, polarizer-analyzer-attenuators (PAZ/PAG), thin film polarizers; electro-optical modulators; optical instruments and apparatus; optical data media; objectives; transparencies, single crystal wafer or chip to serve as a substrate for epitaxal deposition of electronic or photonic material structures or for an infrared imaging or detection unit, laser collimators, semiconductor substrates and wafers, brewster windows, mechanical and optical assemblies, focusing heads, beam director components, beam enhancement tools, beam diagnostic instruments, and integrators, semiconductor diode chips, semiconductor diode arrays, surface-emitting semiconductor diodes, edge emitting semiconductor diodes, optical pumps, 980 pumps, pump laser modules, pump lasers for optical amplifiers, high speed Datacom transceivers, vertical-cavity surface-emitting lasers, components for fiber and direct diode laser systems, laser processing heads and fiber beam delivery systems and components for laser material processing, scientific optical equipment, namely, laser cavities, laser crystals, thin film dielectric coatings for use in the manufacture of scientific optical equipment, polarization components, thin film polarizers, waveplates, polarization rotators, birefringent filter plates, birefringent filter units and lyot filters, prisms, coated optical mirrors, glass laser flow tubes, filters and lenses; components and subsystems for fiber optic communications, namely, tunable filters, sensors, monitors, chromatic dispersion compensators, polarization dispersion compensators, add/drop multiplexers, dynamic gain equalizers, tunable lasers and polarization controllers; components and subsystems for sensing and thermal imaging, namely, tunable optical detectors, tunable optical emitters, tunable optical filters, drive electronics for tunable optical detectors, tunable optical emitters, tunable optical filters, tunable optical sensors, infrared gas sensors, infrared chemical sensors, infrared biomedical sensors, focal plane arrays, wavelength translators, thermal camera engines, thermal cameras and optical amplifiers; Photonic processors, namely, channel processors for dense wavelength division multiplexing of telecommunications signals carried by optic fibers; semiconductor substrates and wafers, silicon carbide wafers and wafer chucks, silicon carbide water cooled mirror, green lasers, and fiber pigtailed laser diode modules, micro-optics for wave-length selective switches, ceramic and metal matrix composites, apparatus for converting thermal and electrical energy for cooling, heating or temperature stabilizing electronics, namely, thermoelectric coolers and converters; electronic component coolers, thermoelectric sub-assemblies, air-to-air thermoelectric assemblies, and air-to-air heat exchangers, namely, thermoelectric-based cooling modules and energy harvesting modules, power generators, and optical windows.


Gupta R.P.,Ii Vi Inc. | McCarty R.,Ii Vi Inc. | Sharp J.,Ii Vi Inc.
Journal of Electronic Materials | Year: 2014

The impact of contact resistance on thermoelectric (TE) device performance grows more significant as devices are scaled down. To improve and understand the effects of contact resistance on bulk TE device performance, a reliable experimental measurement method is needed. There are many popular methods to extract contact resistance, but they are only well suited for measuring metal contacts on thin films and do not necessarily translate to measuring contact resistance on bulk TE materials. The authors present a measurement technique that precisely measures contact resistance on bulk TE materials by making and testing stacks of bulk, metal-coated TE wafers using TE industry-standard processes. An equation that uses the Z of the stacked device to extract the contact resistance is used to reduce the sensitivity to resistivity variations of the TE material. Another advantage of this technique is that it exploits realistic TE device manufacturing techniques and results in an almost device-like structure. The lowest contact resistivity measured was 1.1 × 10-6 Ω cm2 and 1.3 × 10-6 Ω cm2 for n- and p-type materials, respectively using a newly developed process at 300 K. The uncertainty in the contact resistivity values for each sample was 10% to 20%, which is quite good for measurements in the 10 -6 Ω cm2 range. © 2013 TMS.


Trademark
Ii Vi Inc. | Date: 2016-10-13

Optical components and products for use with lasers, namely, lenses, partial reflectors, beamsplitters, mirrors; optical glass, nozzles, beam expander-condensers, waveplates, reflective phase retarders, polarizer-analyzer-attenuators (PAZ/PAG), thin film polarizers; electro-optical modulators; optical instruments and apparatus; optical data media; objectives; transparencies, single crystal wafer or chip to serve as a substrate for epitaxal deposition of electronic or photonic material structures or for an infrared imaging or detection unit, laser collimators, semiconductor substrates and wafers, brewster windows, mechanical and optical assemblies, focusing heads, beam director components, beam enhancement tools, beam diagnostic instruments, and integrators, semiconductor diode chips, semiconductor diode arrays, surface-emitting semiconductor diodes, edge emitting semiconductor diodes, optical pumps, 980 pumps, pump laser modules, pump lasers for optical amplifiers, high speed Datacom transceivers, vertical-cavity surface-emitting lasers, components for fiber and direct diode laser systems, laser processing heads and fiber beam delivery systems and components for laser material processing, scientific optical equipment, namely, laser cavities, laser crystals, thin film dielectric coatings for use in the manufacture of scientific optical equipment, polarization components, thin film polarizers, waveplates, polarization rotators, birefringent filter plates, birefringent filter units and lyot filters, prisms, coated optical mirrors, glass laser flow tubes, filters and lenses; components and subsystems for fiber optic communications, namely, tunable filters, sensors, monitors, chromatic dispersion compensators, polarization dispersion compensators, add/drop multiplexers, dynamic gain equalizers, tunable lasers and polarization controllers; components and subsystems for sensing and thermal imaging, namely, tunable optical detectors, tunable optical emitters, tunable optical filters, drive electronics for tunable optical detectors, tunable optical emitters, tunable optical filters, tunable optical sensors, infrared gas sensors, infrared chemical sensors, infrared biomedical sensors, focal plane arrays, wavelength translators, thermal camera engines, thermal cameras and optical amplifiers; Photonic processors, namely, channel processors for dense wavelength division multiplexing of telecommunications signals carried by optic fibers; semiconductor substrates and wafers, silicon carbide wafers and wafer chucks, silicon carbide water cooled mirror, green lasers, and fiber pigtailed laser diode modules, micro-optics for wave-length selective switches, ceramic and metal matrix composites, apparatus for converting thermal and electrical energy for cooling, heating or temperature stabilizing electronics, namely, thermoelectric coolers and converters; electronic component coolers, thermoelectric sub-assemblies, air-to-air thermoelectric assemblies, and air-to-air heat exchangers, namely, thermoelectric-based cooling modules and energy harvesting modules, power generators, and optical windows.

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