Abstract: A color/color temperature tunable light emitting device comprises: an excitation source (LED) operable to generate light of a first wavelength range and a wavelength converting component comprising a phosphor material which is operable to convert at least a part of the light into light of a second wavelength range. Light emitted by the device comprises the combined light of the first and second wavelength ranges. The wavelength converting component has a wavelength converting property (phosphor material concentration per unit area) that varies spatially. The color of light generated by the source is tunable by relative movement of the wavelength converting component and excitation source such that the light of the first wavelength range is incident on a different part of the wavelength converting component and the generated light comprises different relative proportions of light of the first and second wavelength ranges.

Abstract: Embodiments of the present invention are directed to ternary and/or quaternary catalyst alloys for a direct methanol fuel cell (DMFC). The catalyst has the composition (Pt1-xRux)yM?zM?1-y-z, where M? is selected from the group consisting of W, Mo, Nb, and Ta; M? is selected from the group consisting of V, Co, Ni, Mn, and Cu; x ranges from about 0 to about 1; y ranges from about 0.01 to about 0.99; and y+z is about equal to 1. The catalyst may be deposited onto a porous carrier, and the deposition method may include ion-beam sputtering. The onset voltages of the present compositions are lower than that of conventional Pt—Ru binary systems by approximately 0.355 volts, and thus provide enhanced catalytic activity.

Abstract: Embodiments of the present invention are directed toward the field of spintronics, and in particular, systems and devices capable of performing spin coherent quantum logic operations. The inventive spin valve comprises two ferromagnetic electrode layers, and a non-magnetic conducting layer positioned therebetween. An external magnetic field B0 is applied in the Z direction, such that the two electrode layers are each magnetized in a direction substantially parallel to the external magnetic field. Rather than attempting to change the magnetization of one of the ferromagnetic layers, as is the case in prior art technologies, it is the direction of the electron spin that is manipulated in the present embodiments while the electron is traveling through the middle, nonmagnetic layer. One of the ferromagnetic electrodes may be the tip of a scanning tunneling microscope (STM).

Abstract: A color tunable light source comprises: a first light emitting diode (LED) arrangement operable to emit light of a first color and a second LED arrangement operable to emit light of a second color, the combined light output comprising the output of the source. One or both LED arrangements comprises a phosphor provided remote to an associated LED operable to generate excitation energy of a selected wavelength range and to irradiate the phosphor such that it emits light of a different color wherein light emitted by the LED arrangement comprises the combined light from the LED and phosphor and control means operable to control the color by controlling the relative light outputs of the two LED arrangements. The color can be controlled by controlling the relative magnitude of the drive currents of the LEDs or by controlling a duty cycle of PWM drive current.

Abstract: Embodiments of the present invention are directed toward the field of spintronics, and in particular, systems and devices capable of performing spin coherent quantum logic operations. The inventive spin valve comprises two ferromagnetic electrode layers, and a non-magnetic conducting layer positioned therebetween. An external magnetic field {right arrow over (B)}0 is applied in the Z direction, such that the two electrode layers are each magnetized in a direction substantially parallel to the external magnetic field. Rather than attempting to change the magnetization of one of the ferromagnetic layers, as is the case in prior art technologies, it is the direction of the electron spin that is manipulated in the present embodiments while the electron is traveling through the middle, nonmagnetic layer. One of the ferromagnetic electrodes may be the tip of a scanning tunneling microscope (STM).

Abstract: A color temperature tunable white light source comprises: first and second LED arrangements operable to emit light of first and second wavelength range respectively that are configured such that their combined light output, which comprises light generated by the source, appears white in color. One or both LED arrangements comprises a phosphor provided remote to an associated LED operable to generate excitation radiation and to irradiate the phosphor such that it emits light of a different wavelength range, wherein the light emitted by the LED arrangement comprises the combined light from the LED and phosphor. The color temperature of output white light is tunable by controlling the relative light outputs of the LED arrangements by for example controlling the relative magnitude of the drive currents of the LEDs or a duty cycle of a pulse width modulated drive current.

Abstract: Novel systems for combinatorially screening an array of electrochemical cells are disclosed. The screening aparatus may comprise a system of electrodes and electrolytes common to each of the members of an electrochemical cell array. An electrochemical probe is used to supply a reactive fluid (or reactive species) to only one of the cells in the array at a time. The probe is configured to address each of the cells of the array individually, and to be chemically isolated from all of the other cells of the array. Thus, the cells of the array that are not being addressed by the probe are in a non-active condition. Such a system is capable of combinatorially screening a library of materials, including catalyst, electrode, and electrolyte materials, wherein each of the members of the library defines one of the cells of the array.

Abstract: Disclosed herein are systems and methods for improving the performance of a luminescent concentrator. Performance may be enhanced by incorporating a reflector capable of blocking re-emitted photons from the luminescent material used to make frequency down conversion with a narrow reflection band, while allowing broad transmission of incident sunlight. The reflection band of the reflector that spectrally matches to the bandwidth of re-emission from the luminescent material acts as a luminescence cavity to prevent the outgoing re-emission that cannot be waveguided by total internal reflection to the photovoltaic device(s) located at the side edges of the concentrator.

Abstract: A lighting system comprises at least one excitation source (5), preferably an LED, operable to generate and radiate excitation radiation of a first wavelength (?1); a shade (4) configured to at least in part surround the at least one source (5) and remotely located thereto; and at least one phosphor (16) provided in or on at least a part of the shade (4), wherein the phosphor (16) emits radiation of a different wavelength in response to incident excitation radiation. The phosphor can be provided on a part of an outer or inner surface of the shade. Alternatively, or in addition, the phosphor is incorporated within the shade. The lighting system finds particular application as a hanging, a desk, a floor standing, a wall mountable, a spot, an outdoor or an accent lighting fixture.

Abstract: An LED signal lamp (100) comprises: a housing (102), at least one LED excitation source (108) operable to emit excitation radiation of a first wavelength range (blue light), at least one phosphor material (114) for converting at least a part of the excitation radiation to radiation of a second wavelength range and a substantially transparent cover (104) provided on the housing opening. In one arrangement the excitation source (LED chip) incorporates the phosphor material. Alternatively, the phosphor can be provided remote to the excitation source such as for example on a transparent substrate which is disposed between the excitation source and transparent cover. In other arrangements, the phosphor is provided on the transparent cover or other optical components as a layer on a surface of the cover or incorporated within the cover/optical component material.

Abstract: This invention provides novel cadmium tungstate scintillator materials that show improved radiation hardness. In particular, it was discovered that doping of cadmium tungstate (CdWO4) with trivalent metal ions or monovalent metal ions is particularly effective in improving radiation hardness of the scintillator material.

Abstract: Disclosed herein are camera-based x-ray digital image detectors that contain an assembly of a scintillator screen, a wide-angle optical lens or fisheye lens, and a digital image sensor. Images formed by x-ray radiation on the scintillator screen are projected onto a much smaller area image sensor through a fisheye or super-wide-angle optical lens, hence forming a highly distorted image thereon. Transparent lead-contained glasses or plastics are utilized to shield image sensor from x-ray damage. Imaging distortion and light falloff caused by the lens optics are corrected by software algorithms. Sub-millimeter resolution may be achieved with reduced design complexity and substantially lower manufacturing costs.

Abstract: A lighting system for generating an illumination product comprises an excitation source, blue/UV LED, operable to generate excitation radiation and a remotely located phosphor, photo luminescent material. Excitation radiation is guided from the excitation source to the phosphor by a waveguiding medium, the waveguiding medium being configured such that the distance the radiation travels from the excitation source to the phosphor layer is at least one centimeter in length. The UV/blue excitation source provides excitation radiation to the phosphor(s), causing the phosphor(s) to photo luminesce, and it may also provide a component of the final illumination product. The configuration of the waveguide allows a greater flexibility in lighting system configurations, such as hanging lighting fixtures, desk lighting fixtures, floor standing lighting fixtures, desk lamps, track lighting, spot lighting, accent lighting, lighting panels, inspection lamps and endoscopes.

Abstract: Embodiments of the present invention are directed to compositions and processing methods of rare-earth vanadate based materials that have high emission efficiency in a wavelength range of 480 to 700 nm with the maximum intensity at 535 nm (bright yellow) under UV, X-ray and other forms of high-energy irradiation. Embodiments of the present invention are directed to general chemical compositions of the form (Gd1-xAx)(V1-yBy)(O4-zCz), where A is selected from the group consisting of Bi, Tl, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, and Lu for 0<x<0.2; B is Ta, Nb, W, and Mo for 0<y<0.1; and C is N, F, Br, and I for 0<z<0.1. Methods of preparation include sol gel, liquid flux, and co-precipitation processes.

Abstract: A photo-luminescence liquid crystal display 100 comprises: a display panel 104 and a radiation source 102 (blue or UV LED) for generating excitation radiation for operating the display. The display panel 104 comprises transparent front 110 and back 112 plates; a liquid crystal (LC) 114 disposed there between; and a matrix of electrodes 120 (array of thin film transistors) defining red, green and blue pixel areas of the display and operable to selectively induce an electric field across the liquid crystal 114 in the pixel areas for controlling transmission of light through the pixels areas. Red 130 and green 132 phosphor materials are provided on the back plate corresponding to the red and green pixel areas and respectively emit red (R) and green (G) light in response to the excitation radiation. The LCD can further comprise a blue phosphor material 134 on the back plate corresponding to blue pixel areas.

Abstract: A liquid crystal display backlight comprises: at least one blue light emitting diode (LED) operable to contribute blue light to white light generated by the backlight; a phosphor material which absorbs a portion of the blue light and emits green light which contributes green light to the white light generated by the backlight; and at least one red LED operable to contribute red light to the white light generated by the backlight. In one arrangement the red LED is replaced with a second phosphor material which absorbs a portion of the blue light and emits red light which contributes to the white light generated by the backlight. Many packaging configurations are possible.

Abstract: Embodiments of the present invention are directed in general to novel aluminate-blue phosphors. Specifically, embodiments of the present invention are directed to use of the novel aluminate-based blue phosphors in white light illumination systems, and in display applications such as back lighting in liquid crystal displays (LCD's) and plasma display panels (PDPs). Embodiments of the present invention are further directed toward aluminate-based phosphors having the general formula (M1?xEux)2?zMgzAlyO[2+(3/2)y], where M is a divalent alkaline earth metal other than magnesium (Mg) from group IIA of the periodic table, where 0.05<x<0.5; 3?y?12; and 0.8?z?1.2. In another embodiment, 0.2<x<0.5. The composition may contain a halogen, such as fluorine or chlorine.

Abstract: Disclosed herein are cerium doped, garnet phosphors emitting in the yellow region of the spectrum, and having the general formula (Y,A)3(Al,B)5(O,C)12:Ce3+, where A is Tb, Gd, Sm, La, Sr, Ba, Ca, and/or Mg, and substitutes for Y, B is Si, Ge, B, P, and/or Ga, and substitutes for Al, and C is F, Cl, N, and/or S, where C substitutes for O. Relative to a solid-state-reaction method, the instant co-precipitation methods provide a more homogeneous mixing environment to enhance the distribution of the Ce3+ activator in the YAG matrix. Such a uniform distribution has the benefit of an increased emission intensity. The primary particle size of the as-prepared phosphor is about 200 nm, with a narrow distribution.

Abstract: Novel phosphor systems are disclosed having the formula A2SiO4:Eu2+D, where A is at least one of a divalent metal selected from the group consisting of Sr, Ca, Ba, Mg, Zn, and Cd; and D is a dopant selected from the group consisting of F, Cl, Br, I, P, S, N, and B. In one embodiment, the novel phosphor has the formula (Sr1?x?yBaxMy)2SiO4:Eu2+F (where M is one of Ca, Mg, Zn, or Cd in an amount ranging from 0<y<0.5). The phosphor is configured to absorb visible light from a blue LED, and luminescent light from the phosphor plus light from the blue LED may be combined to form white light. The novel phosphors can emit light at intensities greater than either conventionally known YAG compounds, or silicate-based phosphors that do not contain the inventive dopant ion.

Abstract: Disclosed herein are phosphor compositions comprising a BAM phosphor BaMgAl10O17:Eu2+ and at least one other hexaaluminate that may also be europium activated. The BAM may be mixed with any number of different kinds of heaxaaluminates having a similar crystal structure. The aluminum ratio may also be adjusted to alter the defect structure or to produce a second phase. Addition of another hexaaluminate to BAM enhances emission intensity and resistance to degradation, which is beneficial to applications such as plasma display panels.